Questions tagged [gpio]

GPIO stands for General Purpose Input Output and can be used to receive and send digital signals to and from simple electronics from the Raspberry Pi.

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Raspberry as I2C Slave, how to slow down transfer rate?

I have had minor success using the PIGPIO library and interfacing the Pi as an I2C Slave (Using GPIO Pins 18 and 19 as SDA and SCL) with a Campbell CR1000X Datalogger I am encountering a problem ...
HelpMeImDumb's user avatar
6 votes
2 answers
412 views

Pi4J kills USB bus?

Hello fellow Pi enthusiasts :) I am currently attempting to control a standard 16x2 character LCD display from the PI's GPIO pins from Java. I downloaded Pi4J and wrote a small program to initialize ...
You'reAGitForNotUsingGit's user avatar
4 votes
1 answer
622 views

sh: can't access tty; job control turned off

Yesterday, I was programming GPIO controls for a robot in class and left for a few minutes to work with another group. I came back to find all the GPIO disconnected and sh: can't access tty; job ...
user39770's user avatar
3 votes
1 answer
65 views

magnetic field generated by the engine alternator affects gpio value

I am working on a dashboard for a motorcycle. I created a Qt application on my raspberry pi 4 on a raspberry pi os lite. I have configured one of my GPIO as interrupt using the wiringPi library. ...
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DCF77 time signal emulator by Raspberry Pi Zero WH

This is my first post on this forum. Thanks for being welcomed into this community. I am struggling with my second project with a RaspberryPi. On Github I found a very interesting project of an ...
mvittorini's user avatar
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Is it possible to control servos in both directions on the RPi?

I have been working on controlling servos in one direction with PWM control via GPIO ports on my RPi 3. I've worked with motor controllers that use PWM before and it seems that I should be able to ...
frc_contributor's user avatar
3 votes
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628 views

LIRC mode2 shows no output

I am trying to receive configure an IR remote control for my raspberry and I configured LIRC on the Pi and it works all fine but I won't be able to capture some output with mode2 -d /dev/lirc0 I ...
Chris's user avatar
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Unable to intercept the code of my remote control at 433 MHz with RaspberryPi

I'm trying to reproduce the code generated by my universal 4-channel radio control with RaspberryPI. I cloned my remote with a universal remote like this: I used the libraries included in 433Utils ...
jay's user avatar
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Raspberry Pi button bug, what is happening?

I am new user of raspberry pi. I have two buttons, and some code to run, yet the led will not react to the buttons. It's probably a easy fix, but keep in mind, I am new to robotic and have only ...
Robotechnology's user avatar
3 votes
1 answer
452 views

How to use Rpi GPIO to PWM adjust IR LEDs brightness?

I'm using this circuit for my project, which I referred from https://www.sparkfun.com/news/1396. I don't really understand how current works in GPIO pins, so the question is: instead of connecting ...
emily's user avatar
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Getting button click type

I've been looking for a while to how to get the kind of click of a button on GPIO. Is it a single click? Double? Triple or more? Is it a long click? a very long click? a combination of them? I haven'...
GIMBorgo's user avatar
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Is it possible to virtually trigger a GPIO Input pin when nothing is actually connected to it?

I am trying to use incoming MIDI data on my Raspberry Pi 3's USB port to virtually trigger an input GPIO pin. The reason for this is as follows: I'm using the MIDI out port on a Behringer X-32 audio ...
nathanoday's user avatar
3 votes
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1k views

How to properly trigger multiple Raspberry Pi camera modules via GPIO?

I am working with three Raspberry Pi 3 B boards, which in turns have RPi camera modules V2 connected to each. I followed this very detailed post about triggering another Pi using GPIO pins and it ...
Anna's user avatar
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LED strip PWM on GPIO18 + mono audio output

On the RPi 3 I would like to control a WS2811 LED strip with PWM (GPIO18) by keeping the audio working. It looks like for the RPi Zero (I'm unsure for RPI 3 though) left and right channels of the ...
myoan's user avatar
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RPi Zero WiFi and USB OTG

I'm quite new to this kind of things, but I've jumped out with an idea of a device to give the ability to mount network shares as they where normal pendrives (like for TVs and other old devices). I ...
Samuele Pilleri's user avatar
3 votes
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2k views

Which GPIO pins are used for I2S audio I/O

I am trying to set up the ADAU1781 as an audio codec for the Pi 3 B, communicating with the Pi via the GPIO pins. Which pins would I use for I2S audio input and output? I have been doing a lot of ...
Emmett P's user avatar
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Kodi on a GPIO screen

I recently bought a 3.5 inch TFT touchscreen connected by GPIO to my raspberry. I finally managed to make it work with Raspbian. however, when I launch KODI, the image on the TFT freezes and KODI ...
Pierre-Philippe's user avatar
3 votes
0 answers
607 views

DS18B20 temperature sensor not found in folder

I've bought the camjam edukit 2 for my pi which includes the DS18B20 temperature sensor. However, after going over the instructions 20 times, rebuilding it a same amount and searching online, I still ...
Bram's user avatar
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Raspberry Pi GPRS Connection: Unable to browse after ppp connection is established

I have a persistent problem browsing after connecting my GPRS/GSM Module to Raspberry Pi. I bought the GSM/GPRS Module on amazon here. I have followed the instructions as given on this site https://...
Omoniyi Omotoso's user avatar
3 votes
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interrupts gpio debounce java

My current code does not debounce the input signals from a hardware switch and as a result I get multiple input signals from a single push of the switch. Maybe I'm thinking wrong but I thought that ...
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GPIO23 (BCM) is busy when using /sys/class/gpio but I am able to use wiringPi pin 4 (GPIO23)

I'm having a bit of trouble accessing GPIO23 using /sys/class/gpio/. To clarify a few terms (according to the table on this page): Header pin 16 is BCM GPIO 23, which is wiringPi pin 4. Header pin 11 ...
tompreston's user avatar
2 votes
0 answers
134 views

spi overlay driver don't run due to shared pin11

I'm trying to run old FLIR Lepton driver on Raspberry Pi 3 Model B v1.2 (2015). FLIR SW driver here: https://www.flir.eu/developer/lepton-integration/lepton-integration-raspberry-pi/. PDF guide here: ...
Niko's user avatar
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pigpio Python Raspberry Pi wave PWM generation

I am using pigpio to generate a PWM signal varying in time. I create a wave, which contains one period of a sine wave, in the form of PWM signal. I use wave_send_using_mode and WAVE_MODE_REPEAT_SYNC ...
kubajed's user avatar
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1 answer
659 views

Controlling stepper motor with Raspberry pi

I am building a sorting machine for a project where I want to sort the balls based on their color. For the actual sorting mechanism I am using a stepping motor (NEMA 17 with Driver DRV8825). I ...
Rajat Sharma's user avatar
2 votes
2 answers
327 views

GPIO Button Wiring

Edited: Question re-written Hello, So I am looking to build a system that will have around 400-500 input buttons. These buttons are basically used to select an option so only 1 button will ever be ...
opalbow's user avatar
  • 21
2 votes
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Control multiple (10+) monitors at the same time?

I want to make an art installation where there's an array of monitors are displaying graphic rendered by a single machine. In the picture I shown, each little square represent a monitor, and the ...
zeyuyun1's user avatar
2 votes
1 answer
51 views

Bluetooth Ignition need help smoothing out functionality

I have been working on a Bluetooth authorized push to start the ignition in my truck. Right now it's installed and working but I would like to change the function of the button and shorten the time it ...
Citsk6's user avatar
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2 votes
1 answer
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Problem with 1-Wire devices not showing up on GPIO4

For a project I want to implement 1-Wire communication in a Raspberry Pi Zero W. The goal is to use a Maxim Integrated Max17313 Fuel Gauge for inspecting battery usage. To make sure the implementation ...
Björn Ellensohn's user avatar
2 votes
0 answers
172 views

Input() called from GPIO input (button press) returns error

I'm learning Python whilst tinkering with various 'kits' I got for my Raspberry Pi. Currently messing around with the RFID-RC522, a simple to use RFID read/write board. I have independent Write.py ...
Joe L's user avatar
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Schedule for Raspi OS upgrades to 5.5 kernel & libgpiod 1.5

Several months ago, this blog post appeared in a search. In summary, this post outlines the new char device-based GPIO interfaces. It further states that a full complement of features will be ...
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2 votes
0 answers
151 views

Enabling software i2c causes boot failure

I have a Raspberry Pi 4 model B, fresh installation of Raspberry Pi OS. I am trying to use software i2c to get around the clock stretch bug in the broadcom 2835 chip. I edit /boot/config.txt to ...
user2434545's user avatar
2 votes
0 answers
29 views

Button hardware for RPI

I have the following circuit: I am wondering if this configuration will work if I'm trying to add buttons. I wanted to set them up as GPIO=GPIO.PUD_DOWN and to have it activate on the rising edge, ...
George's user avatar
  • 99
2 votes
0 answers
172 views

Using GPIO on the Bitwizard DMX hat board

I have a rpi 4, with a relays board on top of it, and a Bitwizard DMX hat board on top of that. The Bitwzard board doesn't have a male header on the top, so I am unable to connect my sensors. It was ...
M.Parent's user avatar
2 votes
0 answers
185 views

More than 2 SPI slaves

I like to connect more than two SPI slaves to the Raspberry. Just want help how to configure my Raspberry Pi Zero.
ib95's user avatar
  • 21
2 votes
0 answers
656 views

How to use Rpi UART to debrick a bricked LinkSys G (WRT54GL) Router?

I was working on a project that 'debricks' my bricked router(WRT54GL). Since this is my first time with Serial communication on any device, I have some questions to ask. This is the pinouts for the ...
Gooday2die's user avatar
2 votes
0 answers
65 views

EasyDriver stepper motor through sysfs not moving

I'm trying to activate a stepper motor using easydriver from here https://www.schmalzhaus.com/EasyDriver/Examples/EasyDriverExamples.html using sysfs and C, but it doesn't move. I connected my ...
Cris's user avatar
  • 121
2 votes
1 answer
284 views

Timed trigger for GPIO input

I'm running a raspberry pi system that records fish as they swim passed an IR break beam sensor at a fish ladder. So far the system works well but I'm trying to cut down some of the false triggers. ...
kemistree4's user avatar
2 votes
0 answers
138 views

PWM on pump not working as expected

I am attempting to run a PWM on a pump using rpi.GPIO using the following code: def run_PWM_on_pump(): gpio.setmode(gpio.BOARD) gpio.setup(8, gpio.OUT) p = gpio.PWM(8, 0.5) #also works at ...
Tmello225's user avatar
2 votes
0 answers
384 views

Pulse Position Modulation on Raspberry Pi Zero

I want to WRITE a Pulse Position Modulation (PPM) to an arduino from a raspberrypi. Is the board capable to do this and if so, from which port/pin? A pulse position modulation is a signal that ...
bem22's user avatar
  • 121
2 votes
1 answer
371 views

What is going on with my GPIO pins?

So I wanted to try out my Raspberry 3B+ once again, but I have been sitting here for hours without even being able to turn on a LED. My code: import RPi.GPIO as GPIO import time GPIO.setmode(GPIO....
DubstepZedd's user avatar
2 votes
1 answer
894 views

Setting up the second PWM channel from kernel module not working on RPI 3 model B+

I'm trying to set up both PWM channels (PMW0 and PMW1) on my Raspberry Pi 3 Model B+ from my kernel module. I've successfully set up channel 0 with the desired frequency and variable duty cycle and I'...
A6SE's user avatar
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2 votes
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494 views

Lighting an LED through Pi 4 Model B using Assembly

I have been struggling to light an LED using my raspberry pi 4 model b but have not been able to find a solution. My assembly code : .section .init .globl _start _start: mov r0, #0xF0000000 orr r0, ...
Rahul Wadhwani's user avatar
2 votes
0 answers
2k views

Hardware controlled RTS on a Pi4 not working accurately

We need to use RS485 to talk to one of our custom tools. We need to use hardware controlled rts/cts. I've read so many articles about this but nobody ever says it works for them with fast timing and ...
JSMNST's user avatar
  • 21
2 votes
0 answers
230 views

How to play a 16-bit WAV in raspberry pi 3 b+ with PWM?

I have a 16-bit WAV file, the header of the file as below: WAV header Information: RIFF : RIFF Chunk Size : 5719002 Format : WAVE Sub-Chunk 1 Information: Sub-Chunk 1 ID : ...
Ming Ding's user avatar
  • 147
2 votes
0 answers
226 views

Safe cut power supply from raspberry

I want to cut safe the power supply from the raspberry with a relay connected to the gpio. I know how to connect to relay to the board but.. When the relay turn off the power line will be cut off to ...
Jordy van den Berg's user avatar
2 votes
0 answers
44 views

Method for piling three peripherals on one pi

I'm working on my first pi project, which is intended to use the following three peripherals: GPS -- using UART (pinout) eInk -- using SPI (pinout) battery power supply -- using I2C (pintout on p. 15 ...
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2 votes
0 answers
276 views

SPI NOR Flash: Unstable reads

So I hooked up an Winbond 25Q256JVEQ to my Raspi3 via SPI (spi0.0) and want to read its content. I use the jedec-nor-spi dtoverlay so its available as MTD. However when I want to read the chips ...
bam's user avatar
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2 votes
0 answers
269 views

Issues with Sequent Microsystems 8 relay board

I'm using the Raspberry Pi 3 Model B V1.2, and the Sequent Microsystems 8 Relay Board 2.0. The manual tells you to install this software from github. I installed this and was able to control the ...
Luke Hamel's user avatar
2 votes
1 answer
3k views

Rpi3b+ to Rpi3b+ jtag/SWD connection and OpenOCD

I'd like to hook together two Raspberry pi 3b+ to use jtag/SWD with OpenOCD. I learned it can be done, but implementing it has proven challenging. I have two questions: How to connect the Rpi's. If I'...
T. M.'s user avatar
  • 871
2 votes
0 answers
187 views

GPIO reading high (because its an input) at boot

I am making a thermostat and one of the issues I have with the pi is that on restart it sets all its pins to input which will provide power to devices, in this case a relay being used to switch on and ...
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