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Answer the following technical question about Raspberry Pi. | Title: cannot import OpenCV in a Docker container in Raspberry Pi
Body: I am trying to build a Docker container that can run Python OpenCV code in Raspbian 10. FROM python:3.5-buster
RUN apt-get update
RUN apt-get install apt-utils -y
RUN apt-get install python-opencv -y
RUN apt-get install python3-opencv -y
COPY a.py ... | Three workarounds: Use debian:buster as your base container instead of python:3.5-buster or Put this into your Dockerfile: ENV PYTHONPATH /usr/lib/python3/dist-packages or Similarly, put this at the top of a.py : import sys
sys.path.append('/usr/lib/python3/dist-packages')
import cv2 It's unclear why Python's package ... |
Answer the following technical question about Raspberry Pi. | Title: Connections to my Raspberry PI SSH hang after a while
Body: I have a Raspberry Pi 2 B connected on the network with a static IP. After a fresh reboot, I can connect to it smoothly and it just works: ssh -A <ip> -p <port> . But after, let's say one day or more, the ssh request hangs and I don't know why. ping <ip... | The first step to analyze problems with ssh is to start the connection with verbose output: ~$ ssh -v user@<ip> -p <port> You can improve verbosity of the debug output with -vv or -vvv but I suggest to start with -v to get an overview. Try to connect without forwarding of the authentication agent connection (option -A ... |
Answer the following technical question about Raspberry Pi. | Title: How can I get my hardware to generate interrupts?
Body: sorry if this question is inappropriate, but here goes. I'm trying to build a small circuit that uses a photoresistor ( this one ) to detect when a diode puts light on it. The light will be short and potentially happen several times per second. Usually I wo... | I've hooked up an LDR to a pi's GPIO and ground pin directly. I set up the internal pull-up resistor on the broadcom chip. This created essentially a voltage divider, that would make the pin would read low if a led shined on it, and high is not. Since you only need a yes/no answer there is no need to measure the time t... |
Answer the following technical question about Raspberry Pi. | Title: Raspberry PI boot FAT32 arrangement
Body: I recently thought about tinkering with Raspbian by adding an initramfs. But I have still some unresolved questions about the boot (FAT32) partition. Does the partition have to be on a specific location? I mean, is the 4,2MB of nothing before it necessary? Does the parti... | Here are some answers to your questions: Does the partition have to be on a specific location? I mean, is the 4,2MB of nothing before it necessary? The boot partition must be the first one. It doesn't matter where it starts. The very fist sector of the boot device contains the master boot record (MBR). You can show it ... |
Answer the following technical question about Raspberry Pi. | Title: USB Camera with Rasperry Pi: Sending raw data from dev/video0 to PC through tcp/udp
Body: I want to send the raw USB data to my laptop to process it and then send it back (image processing). Is there any way I can just send the data through tcp/udp without raspi doing all the hard work? | You can't just issue a simple read() on /dev/video*. You have two options: Use OpenCV to open the camera, something like this: // includes, setup code, etc.
Mat frame;
VideoCapture cam(1);
for (;;) {
cam1.grab();
cam1.retrieve(frame);
if (frame.empty() {
continue;
}
// Serialize frame and send it over a n... |
Answer the following technical question about Raspberry Pi. | Title: Raspberry Pi Ethernet network bridge with separate wireless connectivity
Body: As explained here , I built an Ethernet bridge using a Raspberry Pi 3b+. As an extension, I am now trying to connect it to the internet via the WiFi interface. For that I configured the wireless interface as shown here . Then I brough... | I suppose you have completely setup and running Building a 'Packet squirrel" using Raspberry Pi you have linked in your question. It is using systemd-networkd . If you want to extend it with WiFi you also have to use systemd-networkd , in particular to use *.network configuration files. So try this and add setup wpa_su... |
Answer the following technical question about Raspberry Pi. | Title: Using Both +5V GPIO Pins for More Current?
Body: According to this website: https://pinout.xyz/pinout/pin2_5v_power# The +5V GPIO pins can push up to 1.5A of current, and are attached directly to the Pi's power supply. My question is, if I use both +5V pins and connect them in parallel (using diodes just in case... | The 5V pins are already connected (and also to the on-board 5V rail - which, depending on model, is NOT "attached directly to the Pi's power supply"). Using both will make NO difference. (Strictly there will be a minor reduction in resistance, but as this is negligible it would be impossible to measure.) Note the pins ... |
Answer the following technical question about Raspberry Pi. | Title: Has anyone got a Text to Speech engine installed?
Body: Just wondering whether anyone has got a Text to Speech engine installed on the Pi?It would make a great addition to almost any programming project to make it talk to the user! | Yes it is possible; I saw a YouTube video of the Pi reading the news using festival . Use the following command to install festival using Debian $ sudo apt-get install festival festival-freebsoft-utils To make it speak simply pipe it the text or file you want it to read, like so echo "Hello World"| festival --tts Refe... |
Answer the following technical question about Raspberry Pi. | Title: Wifi repeater with bridge: connected but no internet on mobile phone but works fine on MacBook
Body: I live in a dorm where I don't have the physical access to the router. I want to set up a Pi as a Wi-Fi router with a bridge so that I could connect Philips Hue Bridge via Ethernet and then control the bulbs via ... | You are using Access point as WiFi router/repeater, optional with bridge for Raspbian Stretch for your setup with Raspbian Buster. This doesn't work completely out of the box, so I have updated the tutorial. Raspbian Stretch comes with systemd 232 but Buster has systemd 241 that fixes several bugs and changed things. s... |
Answer the following technical question about Raspberry Pi. | Title: SSH Connection refused, even though the openssh-server daemon is running
Body: I did a fresh installation of Ubuntu Mate on my Raspberry Pi 2. Installed openssh-server (in fact it was already installed), and changed the port to be 10022 . However, I cannot access the Pi, from the netowork, neither from the same ... | To troubleshoot your problem run systemctl status ssh . You can see from the output if the ssh server is running and enabled and also see the most recent lines from the log. journalctl -e -u ssh.service could also be helpful to find the issue. It will show everything logged regarding the specified unit. As we clarified... |
Answer the following technical question about Raspberry Pi. | Title: boot failure after flashing RPI-4 raspbian buster on older RPI-3 image sdcards
Body: Last week I flashed Raspbian Buster image to a very old SanDisk 8gb card (slow) using win32diskimager on windows 10, it worked just fine on my new RPI4B-1GB board - and its still functional ... Steps followed :
1) format SD ca... | I found a new recommended imager Etcher recommended by @HawaiianPi in this SD Cards issues thread. Etcher was able to image all the 3 cards without any hiccups and all 3 cards are booting in pi4 now. Win32DiskImager still doesnt work for me on the Buster image on the 16gb cards. Also etcher detected all the sd cards as... |
Answer the following technical question about Raspberry Pi. | Title: Is there a way to unplug the Raspberry pi safely without shutting down
Body: I'm building a kiosk app for a raspberry pi, and the final intention is that it will sit in a pelicase with all the external hardware, with one power cord in. My program has a quit button which safely shuts down the pi by running sudo h... | You seem to be looking for something like https://juice4halt.com/ : a UPS which provides a GPIO signal to the RPi which can be used to initiate shutdown when the external power is lost. Now, sudo halt is not some kind of magic which makes the shutdown safe by releasing pixie dust. You can write a script to do the same ... |
Answer the following technical question about Raspberry Pi. | Title: Is there a way to Stop/Pause an actively recording/on raspi camera?
Body: Starting the Raspi Camera is rather trivial: raspivid -t 10000 -o test.h264 Problem: There is no way to stop this. This seems really stupid to me as, to the best of my knowledge, there is no camera available for retail which requires the u... | Inspecting the source code to Raspivid reveals that there are two ways to interrupt the capture. The first method is to send any SIGNAL to the capture process. The signal is processed by the following code in Raspivid : /**
* Handler for sigint signals
*
* @param signal_number ID of incoming signal.
... |
Answer the following technical question about Raspberry Pi. | Title: Pi stopped connecting to wifi in fedberry?
Body: I'm using a rpi3 b+ and fedberry 27.
I had connected to wifi previously, now it suddenly stopped working. In edit connections I shows that I have my wifi network as a saved connection and my password is correct.
How do I fix this and connect to wifi? | I rebooted my rpi a couple of times and the wifi started working. |
Answer the following technical question about Raspberry Pi. | Title: Copy files to home directory of Raspberry Pi SD card of raspberry pi boot
Body: I want to transfer large files (15 GB total) to the home directory of the Raspberry Pi for processing on the Pi. When I connect the SD card to the computer ( macOS ), I see a volume boot where the only directory is overlays . A find ... | You could put files in the relatively small boot partition. Otherwise NO. macOS doesn't (actually won't - it could) support ext4 partitions. There are a number of 3rd party options for ext4 support, but each new release prevents these from working. Transfer files over the network - there are lots of options; FTP, nfs, ... |
Answer the following technical question about Raspberry Pi. | Title: Auto-login with other account than pi
Body: I want to perform autologin with an account "baa_user" at boot, which is in his own group (baa_user) & have his own home folder, without admin rights at all.
I tried almost all solutions that I found but no one worked.
Change file /etc/lightdm/lightdm.conf worked for p... | I'd guess that you forgot to add baa_user to the autologin group: sudo gpasswd -a baa_user autologin If not, try to login as baa_user manually, maybe you'll find out that something is wrong that prevents the user from starting a desktop session at all. |
Answer the following technical question about Raspberry Pi. | Title: Raspberry Pi 4 not turning off HDMI monitor on idle
Body: NOTE: This issue has since been fixed, as far as I am aware (it works now). If you are seeing something else happen, this may not be it. That does, of course, assume that you haven't edited the config in a way that disables this behavior. In the past, the... | I actually just found out the answer -- it's somehow not yet implemented on the Raspberry Pi 4. The command still works on all previous Raspberry Pi devices.
Since it seems to be rather difficult to find the page that even mentions this command, I'll link it as follows: Video Options in config.txt If anyone has comment... |
Answer the following technical question about Raspberry Pi. | Title: Does the Pi4 have pullups on SDA/SCL?
Body: I can't find a full Pi4 schematic but I gather some previous Pis have had pullups on these two lines whilst others haven't, along with much discussion on whether hats should have a pullup or not. Does anyone have a full Pi4 schematic (not the simplified one on the webs... | I²C requires pullup to work. The unreferenced discussion seems to be misinformed. All Pi models have on-board 1.8kΩ pullups on I²C pins 3,5. I have not used I²C on a Pi4, but assume it is unchanged. You can verify for yourself that pullups are present - just connect a 1.8kΩ resistor from pin 3 to Gnd and the voltage sh... |
Answer the following technical question about Raspberry Pi. | Title: Web Interface to Control Robot Arm attached to Raspberry Pi - HOWTO?
Body: I'm currently working on a project to hook up a robotic arm & webcam to my Raspberry Pi and control said arm through a web inteface. I believe the technical work here involves: Connecting the Robot Arm to the Pi (done). Commanding the Arm... | I'm thinking I will need a script running on the RPi to constantly listen for events/commands. Then hopefully I can setup a webserver of sorts... You've over-complicated things. If you have a piece of hardware connected to the pi and you want to control it via a web interface, all you need is a web server. The server... |
Answer the following technical question about Raspberry Pi. | Title: Missing packages on raspbian
Body: I'm trying to install the libindi astronomy toolset on my Raspberry PI 3 uname gives me Linux raspberrypi 4.19.58-v7+ #1245 SMP Fri Jul 12 17:25:51 BST 2019
armv7l GNU/Linux cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 10 (buster)" For libindi I need to pre-install som... | Okay, after running sudo apt update again I was able to install all missing packages. |
Answer the following technical question about Raspberry Pi. | Title: Raspberry pi SD card issue
Body: once I had sd card corrupted, so I couldn't use it again for raspberry. Tried everything. Now different error. I disabled swap on sd card and placed my script files and some files on ram memory to save sd card from corruption again. Every day made backup from ram memory to sd car... | Please, tell us your exact SD card model.
Anyway, if you ask me, I would recommend using high-speed SD cards, i.e. class 10 would be ok, considering you barely save any money if you use low-speed card. You can check performance of different cards here: http://elinux.org/RPi_SD_cards Btw, how many I/O operations do you ... |
Answer the following technical question about Raspberry Pi. | Title: i2cdetect shows two device address
Body: I have interfaces Atmel 24C04 EEPROM to raspberry PI 3b+ and used i2cdetect to verify if the interfacing is done properly. I am new to this area and trying to learn by doing some hands on. After interfacing i2cdetect is showing two address 0x51 and 0x52 :-( As far as I k... | The 4K EEPROM only uses the A2 and A1 device address bits with the
third bit being a memory page address bit. The two device address bits
must compare to their corresponding hard-wired input pins. The A0 pin
is no connect. Have you connected A0 to ground? Does the device operate properly? It sounds like you are s... |
Answer the following technical question about Raspberry Pi. | Title: How can I close all chromium tabs Automatically once a day before reboot Pi?
Body: When Domoticz and Grafana are open in Chromium on Raspberry Pi 3 b, it uses a lot of memory. That's why I want to close all chromium tabs automatically once a day. I can find a lot about the automatic startup of chromium, tab Domo... | It's not that hard to kill a program. You need the PID for it or the correct name . For Chromium this would be chromium-browser I guess, so run killall chromium-browser . You should also note that there is auto completion in bash. So if you type in killall chr and then hit the ⇥ TAB it will complete the right name if i... |
Answer the following technical question about Raspberry Pi. | Title: Can one run a Raspbery Pi Zero W at load continuously?
Body: I want to use a RPi Zero W to drive a display. This will be putting the CPU on-load pretty much 24/7. Can it handle having load near-continuously? I do have a small metal heat sink on the CPU. I recall reading that if a Pi approaches critical temperatu... | Yes the pi will indeed slow down and can possibly even shut off when the cpu overheats. Because of this in built thermal throttling functionality you should not be able to damage a pi by running it continuously. On a side note you do realize that the pi draws a similar amount of power as a cellphone and has a cpu desig... |
Answer the following technical question about Raspberry Pi. | Title: Wifi disabled after reconfiguring HDMI
Body: I am using a Raspberry Pi 3 A+ with Raspbian Stretch (updated/upgraded about a month ago), connected to a Manga Screen 2: http://wiki.thing-printer.com/index.php?title=Manga_Screen_2 I have used this Raspberry Pi with a 1920x1080 desktop monitor, and also with an 800x... | Okay, I'm not sure why exactly this was causing an issue or why this is the fix, but I successfully restored my wifi connection. If anyone knows why this bug exists, I would love to know. The line hdmi_timings=1080 1 100 10 60 1920 1 4 2 4 0 0 0 60 0 144000000 3 , paired with hdmi_mode=87 allows the user to specify a c... |
Answer the following technical question about Raspberry Pi. | Title: SD file system type VFAT is OK?
Body: The instructions say to format the SD card with FAT the one I bought came pre-formatted as VFAT which I believe is just an extension of FAT is this OK or should I load up GParted and format it again? EDIT: Actually on closer analysis with GParted it is actually FAT32. blkid ... | The one you bought probably has two partitions. The first is a small (~50 MB) FAT32 partition. The second is a larger (2-4 GB) ext4 (linux native) partition. The FAT32 one is required by the Broadcom SoC, I think. It contains some kind of simple bootloader and the kernel. The second one is the root filesystem. shou... |
Answer the following technical question about Raspberry Pi. | Title: Can I use my Pi as an access point in headless mode?
Body: I'm using my Raspberry Pi in headless mode (through ssh) and I want to set it up as a wireless access point. But if, acting as an access point, it forwards packets from the ethernet interface onto the wlan interface and vice versa, does that mean I will ... | To answer your immediate question, packets land in the FORWARD chain after the local routing decision is taken, so packets addressed to the RPi itself (like SSH traffic) should not be affected by these rules: However, you should note that if eth0 and wlan0 interfaces belong to different IP subnets (e.g. 192.168.0.X and... |
Answer the following technical question about Raspberry Pi. | Title: How rpi3 as slave use i2c with wiringPi
Body: I tried to let my rpi3 with wiringPi as slave to receive data from master
and data +1 send to master . mater send 1 to slave (rpi3) My rpi3 SDA is GPIO 18 ,SLC is GPIO 19 the code on my rpi3 : #include<wiringPiI2C.h>
#include<stdio.h>
int main(){
int fd;
fd = wiring... | wiringPi does not support I2C slave mode. It only supports using the Raspberry Pi as an I2C bus master. This in part is because wiringPi uses the underlying Linux I2C driver which only supports master mode. |
Answer the following technical question about Raspberry Pi. | Title: Force a 16bit framebuffer when using a DPI display
Body: I have a 16bit (565) display attached to a Pi with the DPI interface. The problem is that the framebuffer that gets set up is still 32bit and it looks like it's just dropping the LSBs to truncate the output to the screen. This leads to really nasty banding... | Framebuffer color depth can be changed by fbset fbset -fb /dev/fb0 -depth 16 ... Writing the desired framebuffer configuration in /etc/fb.modes could help making the change permanent, but I never tried that personally. |
Answer the following technical question about Raspberry Pi. | Title: Network Log File
Body: Does the RPI have a log file stored somewhere (perhaps /var/log ) for network interactions (such as connections, disconnections, etc.)? | It depends what information exactly do you want to get. The first look is to the journal: rpi ~$ journalctl You can search for the interface name (e.g. eth0, wlan0) and will find if it gained carrier and something like that. Looking for systemd-networkd or wpa_supplicant will give you an overview about these services: ... |
Answer the following technical question about Raspberry Pi. | Title: I want to give Internet to the Raspberry Pi via PuTTy
Body: I can't connect the Raspberry Pi to the internet due to VLAN vulnerabilities. I can connect the Raspberry Pi via Ethernet just in the network to connect to PuTTy. I want to connect the Raspberry Pi via PuTTy to the internet. | PuTTy is a ssh client running on MS Window$ to connect to a ssh server. I haven't seen a setup usable to route to the internet with it. You have to connect the RasPi to a router or configure MS Window$ (if you use it) to "share internet connections". But this isn't an issue belonging to Raspberry Pi. B.t.w. I don't bel... |
Answer the following technical question about Raspberry Pi. | Title: dhclient keeps sending DHCPDISCOVER requests. why?
Body: I connected my rPi to my iPhone via Bluetooth and configured bluetooth interface in the following way in /etc/network interfaces: # iPhone via Bluetooth
allow-hotplug bnep0
iface bnep0 inet dhcp It gets an IP address from the phone and the internet connect... | I did a bit more research and it appears that the problem was in dhclient itself. There are numerous instances of it being mentioned if one googles "dhclient syslog DHCPDISCOVER". I was able to fix the problem by removing all *.leases files from /var/lib/dhcp , purging (not just removing, but purging) isc-dhcp-server (... |
Answer the following technical question about Raspberry Pi. | Title: Raspbian Buster - Keep network interface down on boot
Body: I am configuring my raspberry pi zero w for a project in which I am using a micro-USB Ethernet (eth0) and WiFi (wlan0) as network interfaces. I am using wpa_supplicant to configure wlan0 to connect to a wireless access point. For my specific applicatio... | There a different ways you could achieve what you want. Method 1 – use systemd-networkd If you want to use systemd just follow step 1 and step 3 of this tutorial . Just omit this command systemctl enable wpa_supplicant@wlan0 , so wpa_supplicant won't bring your interface up at boot. If you want to start it manually run... |
Answer the following technical question about Raspberry Pi. | Title: Simulate raspberry pi GPIO
Body: Is there a software to simulate Raspberry Pi hardware design such as proteus? I would like : To use a raspberry pi as a virtual component, Do all the wiring, simulate, Simulate, test code, Check for errors and, Be able to the code implement on real hardware. Is there such softwar... | Apart from the beta Microsoft emulator ( https://azure-samples.github.io/raspberry-pi-web-simulator/ ), which only supports one built in circuit board, the only other emulator i could find is http://www.rpi-emulator.com/ provides an offline downloadable RPi-3 emulator for windows systems. Raspberry Pi Emulator lets you... |
Answer the following technical question about Raspberry Pi. | Title: Pre-built OpenCV on Raspbian Buster
Body: The hassle of installing OpenCV on Raspbian is something many want to avoid, and the easiest way to do this is to use a prebuilt image. I decided to take this route, only to find most pre-built images are still running outdated OS builds, that don't support the pi-4. My ... | You just needed to run apt-get update and retry your command to install your desired package. The issue was that one of the dependencies (libpango in this case) which needed to be installed along with your desired package had been upgraded by your distro maintainer and that your (outdated) local list of packages made a... |
Answer the following technical question about Raspberry Pi. | Title: Should I leave the Raspberry Pi plugged in after shutdown?
Body: Are there any problems with leaving my Raspberry Pi powered even though it is shutdown? Sometimes I forget to unplug it after running sudo halt , so I was wondering if I was affecting the lifespan of my Raspberry Pi or something like that. | Yes, every electronics degrades while it ages, if connected on some power source. The "problem" lies in electronic characteristics itself. One of the phenomena is called electromigration , where IC (actually whole PCB) degrades under various "nonideal" (i.e. working) conditions: current, time, temperature (which is als... |
Answer the following technical question about Raspberry Pi. | Title: Cannot ssh into Raspberry Pi Zero W over wifi after enabling ssh
Body: I'm trying to set up my Zero W to use as a headless server, so I've taken the following steps: Flashed Raspbian Buster Lite onto the SD card Put a file named wpa_supplicant.conf in the boot/ directory with the details for my home's wifi netwo... | Turns out I was looking at the wrong nmap output, and the wrong IP address. Once I put that in, I could connect just fine. |
Answer the following technical question about Raspberry Pi. | Title: Pigpio equivalent of GPIO's event_detected() function?
Body: Is there an pigpio equivalent to GPIO's event_detected() function? I need something that is constantly watching for a button press. The code I currently have doesn't consistently detect it (python sample code below). import pigpio
pi = pigpio.pi()
y ... | The pigpio term is callback . def cbf(gpio, level, tick):
print(gpio, level, tick)
cb1 = pi.callback(22, pigpio.EITHER_EDGE, cbf)
cb2 = pi.callback(4, pigpio.EITHER_EDGE)
cb3 = pi.callback(17)
print(cb3.tally())
cb3.reset_tally()
cb1.cancel() # To cancel callback cb1. There is also wait_for_edge but I would pr... |
Answer the following technical question about Raspberry Pi. | Title: How do I expand a raw disk image?
Body: The official images supplied are raw disk images, which could have been created using dd . How do I make an image bigger? I'm not interested in repartitioning said image as that has already been answered in How can I resize my / (root) partition? . | As explained in this question there are two methods of expanding the image. Below are two examples to expand the file by 1 kilobyte. DD creates a non-sparse file dd if=/dev/zero bs=1k count=1 >> myimage.img Truncate creates a sparse file truncate -s +1024 myimage You probably want to use truncate. A sparse file only wr... |
Answer the following technical question about Raspberry Pi. | Title: Control GPIO pins from C
Body: Most of the libraries, in multiple languages, interact with the GPIO pins via /sys/class/gpio/export , /sys/class/gpio/import , /sys/class/gpio/gpio10/value , etc. However the linux kernel docs clearly state that is the legacy way of doing things. What is the non legacy way of doin... | sysfs has been deprecated and has been replaced with libgpiod . https://www.beyondlogic.org/an-introduction-to-chardev-gpio-and-libgpiod-on-the-raspberry-pi/ The interactions are with /dev/gpiochipx rather than /sys/class/gpio . The only obvious improvement (to me) is that GPIO events now have a time-stamp. |
Answer the following technical question about Raspberry Pi. | Title: Run Raspbian in RAM
Body: Since the first version of Raspberry Pi, I use a customized version of Raspbian in order to mount the rootfs in read-only. Basically I created symlinks in RAM for /var directories so applications don't log to the sd-card anymore. Because RPi4 has plenty of RAM I would like to try to loa... | The short answer is this is possible but there is no simple setting that you change and it just works. It takes a lot of effort. You can't do this directly because ext4 is not a valid format for an initial ramdisk. You must convert the filesystem prior to boot. Mount the Raspbian root partition on another Linux system ... |
Answer the following technical question about Raspberry Pi. | Title: Two dhcpcd services: systemd and init.d
Body: I see that there is a systemd service called dhcpcd5 and an init.d script called dhcpcd. Why both ways? What are the differences and how to choose which run? | Most popular distribution have changed its init system from old SysV to systemd including Debian and its flavor Raspbian. Scripts in /etc/init.d/ are leftover from SysV and they are all emulated by systemd . I think they are only available for backward compatibility of old scripts, or the maintainer of the programs sti... |
Answer the following technical question about Raspberry Pi. | Title: How do I connect Raspberry PI SPI pins to LED Segment via SPI?
Body: The led segment (SPI Slave) I have got has the pin names - VCC, GND, DN, CS, CLK. The raspberry pi model is 3 model B version 1.2. The segment model is XC-3714 . Is my understanding correct here that this is how I need to connect the pins?
I do... | It uses the SPI0.0 interface Pin#24 GPIO08 CE0 connects to CS pin#19 GPIO10 MOSI connects to DIN pin#21 GPIO09 MISO unconnected pin#23 GPIO11 CLK connects to CLK pin#20 GND connects to GN pin#17 3.3V connects to VCC Use https://github.com/rm-hull/luma.led_matrix with https://github.com/rm-hull/luma.core and https://git... |
Answer the following technical question about Raspberry Pi. | Title: How to prevent VNC Viewer window to headless RPi4 from automatically closing after a while?
Body: I'm running an RPi4 headless and connecting over WiFi using VNC Viewer. At some point after opening the viewer window (maybe an hour or two later) that viewer window seems to automatically close. This is an annoya... | By default, the RealVNC server in Raspbian Buster on the Rpi 4 has a 3600 second (one hour) idle timeout. To alter this while in a VNC session: (1) Right click the VNC server icon on the Raspbian desktop taskbar, and select 'Open' from the menu. (2) then in the VNC Connect app, (3) left click the three-line 'hamburger'... |
Answer the following technical question about Raspberry Pi. | Title: Installing interactive brokers IB gateway on raspy 3B+
Body: I found some posts that walk you through the installation but they are very old and don’t work anymore. I tried to install the oracle java for Arm Linux and then modify the IB installation script to point to the newly installed version of java but when... | Make sure you edit the shell script in binary mode! It sounds like you may have edited it as plain text. (eg. use vi -b) |
Answer the following technical question about Raspberry Pi. | Title: Automated (Scripted) Configuration of Raspberry Pi Access Point
Body: Are there any opensource scripts/repos that automate configuring a Raspberry Pi into a Wireless Access Point? | Yes: " pi-ap " a GPL 3.0 repo in Github. I configured a series of bash scripts which automate the configuration of: hostapd dnsmasq wpa_supplicant dhcpcd ...to turn a a Raspberry Pi into a Wireless Access Point. Tested on Pi 3B+ and Pi 4 with both Raspbian Stretch and Buster . Additional Features : Fast DNS: systemd-r... |
Answer the following technical question about Raspberry Pi. | Title: Configure Rpi as router - error when starting network and DHCP interfaces
Body: I looked at several solutions for this question, but none of them worked.
Additionally, I tried some of the tutorials provided (with the necessary changes), but none of them worked My aim is to use a RPi 3B+ as a router with an exist... | To do what you want is simple with systemd-networkd because it has everything built-in and you don't need additional helpers. So I will use it for my suggestion, tested with Raspbian Buster Lite 2019-07-10 updated on 2019-08-22. Updates done with sudo apt update && sudo apt full-upgrade && sudo reboot . First switch ov... |
Answer the following technical question about Raspberry Pi. | Title: Wifi Dongle heating problem
Body: I'm having a sort of "issue" when using a Wifi dongle for my Raspberry Pi, after about 3 minutes connected to a router, the dongle starts to heat up quite alot, almost like a mug of coffee, which I find to be very concerning considering that the dongle casing itself is plastic a... | Unfortunately I don't have enough rep to just comment so I'll just put my answer here... It would help greatly to know what the model of your wifi dongle is. E.g. a model no.
I seriously doubt it is your Pi that is causing the overheating - mine has been on 24/7 using a wifi dongle and I have had no problems. I don't k... |
Answer the following technical question about Raspberry Pi. | Title: RPI 3B+ 'activity' LED always flashes approximately every 1.5 secs With Buster booted external USB SSD?
Body: Booting my pi 3B+ from Buster on a USB SSD 240G Kingston A400, I now get quick pulsing yellow (green?) activity LED flash bursts, every 1.5 to 2 seconds, during normal operation, even when only the Deskt... | I purchased a new SanDisk Ultra 32G SD Card (it was the smallest in the store), for around $10 USD. I suppose an 8G SD Card would have been sufficient for this purpose. The 32G was preformatted fat32. With my RPI 3B+ powered off, I put the blank formatted SD Card in the boot slot on the RPI. The usb SSD was also conne... |
Answer the following technical question about Raspberry Pi. | Title: Install 64bits os on Raspberry Pi 4
Body: I'm not able to run 64-bit OS on my Raspberry Pi 4.
If I do these steps ( https://www.raspberrypi.org/documentation/installation/installing-images/mac.md ) with a 32bit OS it works fine, but if I use Ubuntu or FreeBSD then it doesn't boot. The screen keeps blank. Is ther... | Quoting from FreeBSD/ARM on the Raspberry Pi family For Raspberry Pi 4 (NOT supported yet) use the image for RPI3 You might want to try the latest FreeBSD-13.0-CURRENT-arm64-aarch64-RPI3 (410MB). No RPI4 has been reported installed yet. FWIW, as of Linux see Support of Raspberry Pi . |
Answer the following technical question about Raspberry Pi. | Title: powering the RPi 4 + a 2.5" HDD with 1 power adapter
Body: Ok, so here's the problem:
I want to build a RPi 4 machine for gaming. From what I've read, if I want to attach a 2.5" HDD via usb 3.0 to the Pi 4, it will have to be powered somehow, since the Pi won't be able to power it - at least, not reliably.
Now, ... | I don't know where you heard that the Rpi-4 can't power a 2.5 inch USB-3 hard drive "reliably". I have one RPI-4 running a 2 TB WD Elements 2.5 inch portable hard drive, and another one with a 1 TB Toshiba Canvio drive. Both of these drives are this type: If you run a Rpi-4 with the recommended official power supply yo... |
Answer the following technical question about Raspberry Pi. | Title: autoreconf: command not found
Body: autoreconf -fiv
-bash: autoreconf: command not found I've tried everything listed in this link , but I still can't find any auto(re)conf. pi@no:~/motion $ apt-cache search autoreconf
pi@no:~/motion $ apt-cache search autoconf
pkg-config - manage compile and link flags for libr... | apt-cache search only searches for packages by name and description, not what they contain. For your intended use case you probably should use apt-file : $ sudo apt install -y apt-file
...
$ sudo apt-file update
...
$ apt-file search autoreconf
autoconf: /usr/bin/autoreconf
autoconf: /usr/share/man/man1/autoreconf.1.gz... |
Answer the following technical question about Raspberry Pi. | Title: How to revert from rpi-update to stable build
Body: I have been using a RPi3 for the last year without any issues. I have had rpi-update as part of a regular update process ( cron job).
Lately I have been experiencing crashes. I started to investigate, and while there is nothing helpful in the syslog I saw a new... | "In normal circumstances there is NEVER a need to run rpi-update as it always gets you to the leading edge firmware and kernel and because that may be a testing version it could leave your RPi unbootable". https://www.raspberrypi.org/forums/viewtopic.php?p=916911#p916911 Even the rpi-update documentation now warns "Eve... |
Answer the following technical question about Raspberry Pi. | Title: Raspberry Pi 4 VNC Remote Connection Desktop Error
Body: Surroundings Raspberry Pi system: Raspbian Buster with desktop Direct connection using fiber Problem VNC connection remote desktop error: cannot currently show the desktop , I have enabled VNC and boot desktop automatic login option when booting, but still... | Yes, in addition to the above two operations must also set the resolution, the specific location in Advanced Options > Resolution, select the appropriate resolution. |
Answer the following technical question about Raspberry Pi. | Title: Can't return any values from ttyUSB0
Body: I'm using a SICK S300 scanner connected via Diagnostic cable to my Raspberry Pi, and it shows the connection as /dev/ttyUSB0 however I can't retrieve any data from it whatsoever. Here is a simple Python program I am using to attempt to read the incoming data. import ser... | Using an RS422 to USB connection I was able to recieve data through the same port /dev/ttyUSB0 |
Answer the following technical question about Raspberry Pi. | Title: Raspberry Pi won't connect to NAS Server
Body: I can't connect to my local NAS from my Raspberry Pi, and yet, on my Mac I can using the old Cmd+K. So far, I've tried several options, including : sudo mount -t cifs -o username=USERNAME,password=PASSWORD // 192.168.X.X /mnt/ which tries to connect as root ; sudo m... | samba-client is a so-called virtual package. From the FAQ: Debian GNU/Linux FAQ <p>6.8 What is a Virtual Package?</p>
<p>A virtual package is a generic name that applies to any one of a group of packages, all of which provide similar basic functionality. For example, both the tin and trn programs are news readers, and... |
Answer the following technical question about Raspberry Pi. | Title: "structure needs cleaning" after sudo apt-get upgrade
Body: distribution version: 10 (buster) kernel version: 4.19.57-v7+ Basically, I haven't done anything on this Pi except download a 3.5in touchscreen driver. Then I created a static IP address Then (from ssh ) I attempted to run sudo apt-get update , which re... | An SD card format and Raspbian re-flashing did the trick |
Answer the following technical question about Raspberry Pi. | Title: Stacking multiple TV hats
Body: Is it possible to stack multiple TV hats on each other? I would like multiple users to watch TV channels on different frequencies (MUXes). | It's not possible because there's no way to change the SPI chip select pin from CE0. https://www.raspberrypi.org/forums/viewtopic.php?t=227520 https://www.raspberrypi.org/forums/viewtopic.php?t=247569 |
Answer the following technical question about Raspberry Pi. | Title: Coproc in shell script
Body: I'm trying to do a simple shell script that will make my raspberry's bluetooth discoverable but i'm facing some issues. My raspberry is running Raspbian. Running this through command line works perfectly: coproc bluetoothctl
echo -e 'discoverable on' >&${COPROC[1]} But when i create ... | Invoke it either with ./test.sh or bash test.sh . By using sh test.sh you're falling back to shell only, not Bourne Again SHell, bash. |
Answer the following technical question about Raspberry Pi. | Title: Synchronizing video on multiple raspis
Body: I would like to synchronize one feed (ie. this super maly fight scene from Puss and Boots...lets assume I have it on disk and in .h264 ) across 3 raspis (via a network) each connected to one HD monitor for a total of 3 HD monitors. I can easily do this via mplayer as ... | I added synchronizing capabilities to omxplayer, you can checkout the repo here . Note this is still in development, however, to the best of my knowledge, it is the only way to get reliable synchronization across multiple raspis. |
Answer the following technical question about Raspberry Pi. | Title: Run forever task as root in init.d script on startup
Body: I'm trying to start a nodeJS Server on Raspbian on startup. Everything works fine with this script: #!/bin/sh
#/etc/init.d/myService
### BEGIN INIT INFO
# Provides: myService
# Required-Start: $all
# Required-Stop:
# Default-Start: 2 3 4 ... | Since version 8 (Jessie) Debian has switched to the new init system systemd . All Debian flavors, including Ubuntu and Raspbian, followed this. So old style init system SysV is deprecated and no more available. Its init scripts in /etc/init.d/ are only emulated by systemd for downstream Compatibility with SysV . But th... |
Answer the following technical question about Raspberry Pi. | Title: NOOBS stuck at rainbow screen - Raspberry Pi 4
Body: I formatted my SD card to fat32 using GParted and copied all the files from the official NOOBS Lite download: https://www.raspberrypi.org/downloads/noobs/ . I unzipped using unzip command on the terminal. When I turn on the rainbow appears and the Pi gets stuc... | I connected it to the other HDMI port and the image appeared, it was actually booting but showing the rainbow through that port. |
Answer the following technical question about Raspberry Pi. | Title: How to setup port forwarding & DDNS with noip
Body: Followed the tutorial for webcam server here: hackernoon.com/how-to-access-your-raspberry-pi-camera-from-anywhere-544ab9e5bacc When I visit https://<host name>.ddns.net:8081 the browser can’t connect to the server. I’ve configured my internal port and external ... | The first thing I notice is that you wrote about http s , but acording to the linked site, the web(cam)server on the pi supports http, only. Maybe, you give it a try? Test if you can connect to the server from within your local network, i.e. from your mobile when connected to WiFi by visiting http://raspberrypi:8081 (M... |
Answer the following technical question about Raspberry Pi. | Title: How can I get the image recorded from a rear-view camera?
Body: I have a rear-view camera ( NAVITEL MR250 ) which I use everyday. I got into image processing and I thought a good personal project would be to create a "self-driving car" (Quotation marks because I just wanted to do the image processing part). I to... | You most probably won't be able to. You will have to find out many things up front: is there a video output (analog or digital) is there a connector to communicate with the device is the camera interface something common (the Pi will only work with CSI and USB) If you cannot answer any of those questions with a yes the... |
Answer the following technical question about Raspberry Pi. | Title: Nested Else issue. Very Basic
Body: This is the code I am using to operate a relay to open my garage and the garage status is checked by a magnetic switch. However there is an issue with the logic can someone help me please as I am very new to Python. If the garage is already closed (gpio 4 input true) it shoul... | You're not actually re-checking GPIO4, you're just re-reading the variable mag1 . One way to fix this would be to add mag1=GPIO.input(4) after your time.sleep(20) . import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(18,GPIO.OUT)
GPIO.setup(4, GPIO.IN, pull_up_down=GPIO.PUD_DOW... |
Answer the following technical question about Raspberry Pi. | Title: Long range interface between a Raspberry Pi and a smartphone?
Body: I would like to control a Raspberry Pi 4 with my smartphone (for my drone). Now I'm looking for an interface between the RPi and my Android phone. Requirements : Control with a web interface or app Range: at least 1 km (0.62 miles) . Data rate: ... | In the end I opted for this solution: Android Phone > Serial > Self built antenna with an Arduino > RFM95W > Raspberry Pi 2km range Cheap Fast Easy Links: Android Serial RFM95W |
Answer the following technical question about Raspberry Pi. | Title: Errors while trying to install nginx-extras on buster on an RPi 3 B+
Body: I tried to install with following commands: sudo apt update
sudo apt install nginx-extras This was the output: Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will... | This solved the problem: sudo apt update --fix-missing |
Answer the following technical question about Raspberry Pi. | Title: Can malware persist in the Pi outside of the OS/SD card?
Body: Please let me know if this question is more appropriate for Security . What kinds of damage can an attacker with physical access to a Pi cause? In a desktop PC or laptop, an attacker with physical access might be able to hide malware in, say the devi... | If you have physical access to a computer, including Raspberry Pi, you do not have any chance to avoid attacks. The attacker can just do what he want with the hard- and software, even simply replace the whole Raspberry Pi with a prepared one. He has lots of time to prepare a RasPi before hand, and then replace it very ... |
Answer the following technical question about Raspberry Pi. | Title: Screen blanking in X-Windows on Raspbian
Body: I'm on the similar project and issue as OP with screen-blanking (HDMI output), running a Raspbian Server 2.4: Disable screen blanking in X-Windows on Raspbian The standard user pi logs the session that auto-starts after a boot. I have tried different approaches with... | I created a xorg.conf file with the following input and now it stays up: Section "Monitor"
Identifier "Monitor"
Option "DPMS" "false"
EndSection
Section "ServerLayout"
Identifier "ServerLayout0"
Option "BlankTime" "0"
Option "StandbyTime" "0"
Option "SuspendTime" "0"
Option "OffTime" "0"
E... |
Answer the following technical question about Raspberry Pi. | Title: How to select audio output in Raspberry 4
Body: I have a youtube video playing in Chromium and I can hear the sound that comes from HDMI, to the built-in monitor speakers. How can I select where the audio goes?
I'd like to hear the sound in the speakers connected to the audio jack.
I'm using Raspbian and in the ... | The Advanced Options in raspi-config has an option to select default audio output. Right clicking on the speaker icon in the GUI also displays output options (including, in my case, Bluetooth). |
Answer the following technical question about Raspberry Pi. | Title: "Permission denied (publickey)." after flashing with Raspbian Buster Lite
Body: I recently received a Pi Zero W, and I am attempting to set it up for the first time. I loaded a recent download of Raspbian Buster Lite, modified config.txt with "dtoverlay=dwc2" and cmdline.txt with "modules-load=dwc2,g_ether" imme... | This seems to be an edge case, but the root cause was an invalid Bonjour installation, which prevented the raspberrypi.local hostname from being resolved. This became apparent as all .local hostnames would resolve to my own machine. As I was unable to get a correct Bonjour installation, my solution was to install iTune... |
Answer the following technical question about Raspberry Pi. | Title: Run a code without being on the physical machine
Body: I have some devices (i.e. leds) that I need to control on a Raspberry Pi, but I was thinking if there is a way in which I can put the code in a server, and then when the raspberry Pi receives a certain command to turn on a led, it takes the command from the ... | My pigpio library lets you control the GPIO of one or more Pis from another machine on the network. The other machine may be a Windows, Linux, Mac, or Android machine. It's simplest if the other machine can run Python. http://abyz.me.uk/rpi/pigpio/python.html An easier approach might be to use the gpiozero software. ... |
Answer the following technical question about Raspberry Pi. | Title: Direct Ethernet IPCam and Wifi for browsing - Networking setup
Body: I would like to connect 2 ipcams via a switch to the RPI 3B+, and use the WiFi to connect to a router (to use the webbrowser etc), and also use the router for VNC The ethernet is used to send commands to the camera and also watch the streams. W... | This problem can be reduced to make the RasPi a router with an WiFi uplink to the local hotspot/router and connect to a local wired network. It is no problem to use the wired and wireless connection at the same time because you asked it. If you mean to have all devices on the same subnet 192.168.1.0/24 then it isn't po... |
Answer the following technical question about Raspberry Pi. | Title: Not able count Pulses Generated by PLC
Body: I am using the below code to capture the pulses and count pulses for a specified interval but the output not as what i expected. For every pulse it is giving uncertain value. The pulse i want to count is from a motor that will generate one pulse per rotation. I am us... | You are using a long deprecated version of the pigpio Python module. Where did you find it? I suggest you download the latest version of pigpio from the Raspbian repositories. Try this code. !/usr/bin/env python
import time
import pigpio # http://abyz.me.uk/rpi/pigpio/python.html
pi = pigpio.pi()
if not pi.connecte... |
Answer the following technical question about Raspberry Pi. | Title: RPI Zero as Keyboard: Convert key codes from SHOWKEY to write into /dev/hidg0 HID packet
Body: I'm using RPI Zero W as keyboard gadget. It's supposed to act as keyboard getaway from Bluetooth keyboard to USB keyboard. I'm running "showkey" shell command process giving me codes of just pressed keys. I can get pre... | The fastest solution appeared to be manual test and compare of all the keys one-by-one. |
Answer the following technical question about Raspberry Pi. | Title: I can't get the OSD with omxplayer
Body: I installed omxplayer on Raspbian Buster Lite (no Desktop, no Xserver) on an rpi3. On my previous builds when I paused a video I would get an OSD with the current runtime and time remaining. Now nothing appears. I tried pausing through dBus and terminal. Neither shows... | I usually use omxplayer wrapped in a script. When I ran it naked I saw the error message "Error: Unable to open font". A little search and I found omxplayer uses these fonts for the OSD.. /usr/share/fonts/truetype/freefont/FreeSans.ttf
/usr/share/fonts/truetype/freefont/FreeSansOblique.ttf I downloaded the ttf from ... |
Answer the following technical question about Raspberry Pi. | Title: Restart wifi using bash script and systemd service?
Body: My rpi is connected to a captive portal hotspot. I have prepared a python login script to login to the captive portal and it was working fine. But sometimes the wifi is getting disconnected and at that time i need to restart the wifi. Hence I have prepare... | Modified the .service file as follows [Unit]
Description=captive portal automation
[Service]
Type=simple
KillMode=process
ExecStart=/home/pi/.caportal/do.sh That's it! Thanks for the comments |
Answer the following technical question about Raspberry Pi. | Title: Addressing PCA9865 Servo Driver
Body: Although not directly related to the Raspberry Pi, the piece of hardware I'm attempting to understand can be utilized by the Pi and it's a relatively basic concept that I'm looking for more information on, I'm just not sure what it is called to research it. The PCA9865 Servo... | A5 to A0 should be thought of as a binary number. Ax is 1 if there is a solder bridge, otherwise 0. A5 A4 A3 A2 A1 A0 Decimal
0 0 0 0 0 0 0
0 0 0 0 0 1 1
0 0 0 0 1 0 2
0 0 0 0 1 1 3
0 0 0 1 0 0 4
0 0 0 1 0 1 5
0 0 0 1 1 0 6
0 0 0 1 1 1 7
0 0 1 0 0 0 8
...
... |
Answer the following technical question about Raspberry Pi. | Title: Using Normal GPIO Pins as I2C (required)
Body: We are attempting to use the Raspberry Pi as an embedded software platform. We are writing this in python, but currently we have it wired up to use 3 separate I2C busses. We have two of them wired to the normal I2C pins, but we require the use of a normal bog-standa... | You can use any spare pair of GPIO to create a software I2C bus. As you have noted you will need to use external pull-ups to 3V3 on the chosen GPIO. You need to add an entry to /boot/config.txt For details see /boot/overlays/README Name: i2c-gpio
Info: Adds support for software i2c controller on gpio pins
Load: d... |
Answer the following technical question about Raspberry Pi. | Title: intermittence in Adresses on a I2C bus when using more than 5
Body: Hello im doing and experiment trying to Expand my raspberry to use 7 I2C devices (MCP23017 E/SP) its my first time using more than 1 MCP Im using SparkFun Solderable Breadboard to conect Pi 5v / GD to a rail and SCL and SDA to the other rail Adr... | First off, all signal pins on the Pi are 3.3V. If you are powering your circuit from the 5V rail, you are going to damage your Pi if you haven't already partially fried it. What value pull-ups are you using? (You are using pullups, right?) Make sure all your wires are as short as possible, and really make sure you are ... |
Answer the following technical question about Raspberry Pi. | Title: Virtualizing raspberry pi (as guest) on bochs?
Body: Is it possible to run raspberry pi as a VM on Bochs (the hypervisor)? Actually I've an R Pi application which I would like it to run on a PSP game console, also I've found that the bochs hypervisor is supported on PSP: http://www.hacker.co.il/psp/bochs/ The ap... | No, this does not work. Bochs emulates IA-32 alias x86 architecture. It is NOT a hypervisor. Raspberry Pi is running on ARM Cortex A series (or ARM 11 in case of the original Pi and Pi Zero). You will need to find another way to get Tic-80 on your PSP. Either an emulator for ARM architecture or a direct port of Tic-80 ... |
Answer the following technical question about Raspberry Pi. | Title: Why is `wget` hanging?
Body: I have raspbmc (Debian) installed on my Raspberry Pi and it seems to not be able to download anything? wget seems to stall yet it can ping! The same happens for apt-get Resolving google.com... 173.194.41.160, 173.194.41.165, 173.194.41.163, ...
Connecting to google.com|173.194.41.160... | I think your IP configuration might not be correct.
Try ifconfig -a and review your configuration.
I came to this assumption because your system time doesn't get set via NTP. An other possibility is a proxy configuration.
You could see it with export | grep -i proxy |
Answer the following technical question about Raspberry Pi. | Title: Raspberry Pi would not boot
Body: I just successfully installed a rapberry debian provided by NOOBS and the installation process
went quite smoothly. But after it has been installed, I cannot boot the Pi again. The green light will flash once when the power is on, and I can see the lauching screen but afterwards... | I solved the problem. I changed to a 8GiB SD card instead of the 16GiB card I had before, and it worked. It was probably just a bad card for the Pi. |
Answer the following technical question about Raspberry Pi. | Title: SD card broken readonly switch, now I broke /boot, no USB keyboard in initramfs. Any way to write to card?
Body: TL;DR: RPi won't boot, other computers check the R/O physical switch, the switch tab is long lost. I have a backup with previous, working state, but can't write it onto the SD card. I have a RPi1, usi... | On many readers, it's enough to insert the SD card not all the way in, so that the pads make contact, but the place where the lock should be is still occupied by the edge of the card. The edge of the card will then activate the lock detection mechanism which allows writing. Otherwise, the trick with the sticky tape is ... |
Answer the following technical question about Raspberry Pi. | Title: Will this work out (usb hub + rpi zero w + Zishan Z1 DSD)?
Body: Well, I want to connect Rpi zero W and Zishan Z1/2 DSD in one case, but with both devices working in one port connected to PC. (with working usb device in Rpi if in "portable" mode or in both situations) So, the most easiest way to do it is obvious... | I think your config is OK. ZiShan Z1 should take much less than 50mA. RpiZ takes less than 300mA. In other words, a piece of cake for USB2.0 hub. References Zishan DSD Pro Battery = 3000mAh Battery life = 8H (3000 / 8 ~= 40 mA) http://audiorealviews.site/index.php/2019/03/24/zishan-dsd-pro-realview/ How much power do... |
Answer the following technical question about Raspberry Pi. | Title: Powering Raspberry Pi 4 With OnePlus Charger 5V 4A
Body: I´m planning on buying Raspberry Pi 4 and i don't want to waste money on a charger if the one that I have for my phone technically works. I can save a few bucks for buying the case alone. I don't use it because I don't want to lower the phone battery life ... | Any device that supplies 4 amps at 5 volts will work to power the Pi4B. |
Answer the following technical question about Raspberry Pi. | Title: About Power supply for Pi 4b
Body: I have bought Pi 4b but now I don't wanna buy separate power adapter for it, I already have 5V,4A power adapter of my smartphone so can I use it for Pi 4b also?? | Raspberry Pi 4B is rated for 3A by the manufacturer. You can always use a charger that can deliver higher current. It is necessary that your charger must not exceed rated voltage, which in this case is 5V. Usually, 5V adaptors give out ~5-5.8V, which the Pi can handle without any issues. |
Answer the following technical question about Raspberry Pi. | Title: Apply 3.3V onto an output GPIO pin?
Body: My question in short: Will I damage my Raspberry Pi 4 if I apply (its own) 3,3V onto a GPIO pin that is set to output mode? (With current limiting resistor, of course) I ask this question because this is what I want to do: | The answer to your question is - it depends. With the circuit you have drawn it will be OK. If the output is HIGH no current will flow; If the output is LOW 3.3/5 ~ 660µA will flow into the GPIO, which is well within its specifications. |
Answer the following technical question about Raspberry Pi. | Title: HDMI Output works with NOOBS but not after I install an OS
Body: I am brand new to RasPi.
I installed the NOOBS onto an SD card. (formatted using SDFormatter)
On boot the NOOBS screen came up on HDMI.
I selected Raspbian.
After NOOBS installed Raspbian and (I assume) booted the OS there was no HDMI.
Now when I... | I think this is the same problem, check linquize solution: Blank screen after installing Raspbian In short, the problem is that the config-file is overwritten by the template. You could try to let it finish the boot-process, and with no signal on the HDMI, try to connect to the Pi via SSH. Then edit /boot/config.txt an... |
Answer the following technical question about Raspberry Pi. | Title: What is causing gaps in logs?
Body: I am examining the log of my program, which runs on a Raspbian 9, on an SD card. The program is started and managed by systemd , and the logs are handled by journald . Occasionally the log contains gaps, such as the one highlighted below: You can see that a period of almost 24... | The time gap can be explained because the Raspberry Pi does not have a realtime clock built-in. Raspbian takes effort to make the gap as small as possible and don't always start with 1970-01-01. It stores the date/time from the last shutdown and starts with it. So you will first see this date until the synchronization ... |
Answer the following technical question about Raspberry Pi. | Title: What is the OpenELEC/XBMC equivalent of ctrl-alt-del?
Body: OpenELEC freezes on me intermittently in the middle of video playback, likely because the video file itself is corrupt. What can I do to bring it out of its frozen state, and, e.g. back into the file explorer (or somewhere else equally sensible)? | OpenELEC and XBMC use the Xorg server as the foundation of the GUI. By default, X can be exited via Ctrl + Alt + Backspace . Try that next time this happens; if it works you will either get spit to console or a login screen, but the video player will be dead. Unfortunately, getting the keystrokes through the lock-up ... |
Answer the following technical question about Raspberry Pi. | Title: Slight dip on the GPIO 5v line when LEDs are on
Body: I have my raspberry pi set up to do two main things: control 16 LEDs via 16 transistors each connected to an out pin. The LEDs are collectively fed the 5V from the GPIO. power a chip also on the 5V line The chip itself is not important (its a DAC) beyond the ... | Question How to keep (1) 5V DC power supply for Rpi and (2) 5V DC power supply for external circuits, eg, LEDs, relays etc as steady as possible, say, less than 0.02V fluctuation (ie, "slight dip" in Rpi 40 pin connector 5V power, when switching on LEDs)? Solution Use two separate 5V regulated power supplies, one for R... |
Answer the following technical question about Raspberry Pi. | Title: Why don’t GPIO lines work for DS18B20 Sensor?
Body: Recently, I bought a DS18B20 temp sensor to monitor my fermentation temp of my beer and assumed I could just hook up the power, ground and data to their respective pins on the Pi but I could never get it to work. I looked online and there were a lot of tutorial... | To enable 1-wire (with or without parasitic power) you need dtoverlay=w1-gpio dtoverlay=w1-gpio-pullup in /boot/config.txt |
Answer the following technical question about Raspberry Pi. | Title: Can't get VPNSecure installed/running correctly on RPi3B with Raspbian
Body: I'm trying to set my RPi 3B running Raspbian up with a VPN and I already subscribe to VPNSecure so I attempted to install it using the Linux instructions here: https://support.vpnsecure.me/articles/getting-started/linux-vpnsecure-client... | Raspbian is a 32 bit operating system. Executable files on Linux have the ELF format (similar to EXE files on MS Window$). The error message ELF: not found is typical if the operating system cannot find that a file is executable, in particular it isn't a 32 bit program. You should use the 32 bit installer and fix the e... |
Answer the following technical question about Raspberry Pi. | Title: USB ports on USB hat not recognised
Body: I have a setup that uses 4 USB cameras, a USB cell modem and a USB weather station. I deal with this by adding a powered USB hub. I just bought a Waveshare USB hat which looked like a tidier solution. The USB ports on the hat are not recognised although the power light c... | I will assume you have this USB hat: Never used it myself, but according to the wiki : You have to attach the USB HUB HAT to a Raspberry Pi B+/2B/3B with a USB cable Have you done that? |
Answer the following technical question about Raspberry Pi. | Title: Raspbian: dpkg hangs during raspberrypi-kernel package upgrade
Body: while doing an apt upgrade on my Raspberry Pi 4 (Raspbian 10 - Buster), dpkg was interrupted during setup of the raspberrypi-kernel package: raspberrypi-kernel (1.20190819-1) wird eingerichtet ...
»Umleitung von /boot/bcm2708-rpi-b-plus.dtb zu ... | Found out, that the reason for the hanging dpkg process was a hanging call to sync in two post-installation-scripts: raspberrypi-kernel.postinst and raspberrypi-bootloader.postinst , both located at /var/lib/dpkg/info/ . After remounting root-fs using the sync option ( mount -o remount,sync,rw,noatime / ) and commentin... |
Answer the following technical question about Raspberry Pi. | Title: Automate delivering custom updates to several identical Raspberry PIs?
Body: There are several RPIs hosting an (always identical) custom set of software, and it's configuration. Each RPI runs binaries, triggers shell scripts, has configs, and any or all of those moving parts may have to be updated over the Inter... | I would recommend you to have a look at Ansible as I am already using it to update some hundred Pis that are distributed over various places and sometimes also are only connected via LTE. To reach all those Pis, I configured an openvpn-server to which all Pis connect when they boot. In Ansible you can write playbooks a... |
Answer the following technical question about Raspberry Pi. | Title: Enabling GL driver makes all sorts of problems on a Pi 3!
Body: Situation: Raspberry Pi 3B running freshly flashed Buster SD card. Graphics: Pi => hdmi-to-VGA => monitor. Pi and monitor are on same power strip. Both turn off together once pi has shutdown. Updated, upgraded and autoremoved. No dpkg errors. OpenGL... | I have reached a partial solution for each of my original points. Mouse pointer jittering/bouncing/jumping/flickering: No known
solution, but some /boot/config.txt flags make it more noticeable. More RAM used: Well too bad, turn on swap if necessary. Entire screen freezing: turns out it was related to low voltage, but ... |
Answer the following technical question about Raspberry Pi. | Title: I2C communication between two arduino masters sending events and one raspberry pi slave
Body: I have two arduinos intercepting events. They have to deliver these events to a raspberry pi. According to my understanding of the I2C protocol, the RPi must be configured as slave, and the two arduinos as masters. Now,... | There can only be one I2C bus master (except in circumstances which do not apply here). There is no Pi kernel support for it to act as an I2C slave. If using I2C the simplest solution (from the information provided to date) is for the Pi to be I2C master and for the Arduinos to be I2C slaves. The Arduinos could signal ... |
Answer the following technical question about Raspberry Pi. | Title: PIGPIO not detecting I2C device but i2cdetect -y 1 detects it and I can even run my codes well in SMBUS
Body: I have a Raspberry Pi 3 Model B+.
My I2C device which is this (exact breakout board) isn't getting detected through PIGPIO Library. The sensor works very well with the example codes which uses SMBUS libr... | The most likely solution is that the I2C device does not support the SMBus read byte command. i2cdetect uses a variety of probing methods and chooses the one most likely according to the device's address. The pigpio example script is much simpler. See man i2cdetect As there is no standard I2C detection command, i2cdete... |
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