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.

615 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
6
votes
0answers
228 views

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 ...
5
votes
0answers
2k views

Can I control GPIO Pins when using Android on the Pi 3?

I want to install Android on my Raspberry Pi for implementing a GUI app, which is easy to create using Android Studio. But now I am confused about how to control the GPIO pins on the Pi 3 to turn on ...
5
votes
2answers
379 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 ...
4
votes
2answers
688 views

Controlling a High Power 13V DC Motor with in-built Hall Effect sensor

I am a beginner with electronics and RPi. I have a Brushed DC Motor that runs at a constant 13V and draws about 4-5 A while running and about 18-20 A at stall. It also has a single Hall effect sensor ...
3
votes
0answers
523 views

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 ...
3
votes
0answers
96 views

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 ...
3
votes
0answers
381 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 ...
3
votes
0answers
109 views

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 ...
3
votes
1answer
290 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 ...
3
votes
0answers
830 views

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'...
3
votes
0answers
164 views

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 ...
3
votes
0answers
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 ...
3
votes
1answer
1k views

Not getting a response from a connected PIR sensor

I have a PIR sensor which I'm using connected to a Raspberry Pi 3 Model B as part of a Magic Mirror project. I'm running this module for the sensor. I've had the Motion Sensor working before, but now ...
3
votes
0answers
636 views

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 ...
3
votes
0answers
1k views

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 ...
3
votes
0answers
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 ...
3
votes
0answers
581 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 ...
3
votes
0answers
515 views

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 ...
3
votes
0answers
4k views

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 ...
3
votes
0answers
4k views

Daisy Chaining MCP23017 & Addressing

I'm looking to daisy chain multiple MCP23017 chips (upward of 10) to essentially give me more IO to play with from my Pi. I've started to work on the circuit diagram, but I'm really lost with all ...
2
votes
0answers
38 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. ...
2
votes
0answers
168 views

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 ...
2
votes
3answers
197 views

connect multiple temperature sensors to rpi

I need to connect multiple temperature sensors to my RPI. can you, please, elaborate whether/how can this be done with this or this unit? or can you suggest other unit? I need to measure temp on the ...
2
votes
0answers
25 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, ...
2
votes
0answers
115 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 ...
2
votes
0answers
68 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.
2
votes
0answers
321 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 ...
2
votes
0answers
69 views

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 ...
2
votes
0answers
77 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 ...
2
votes
0answers
249 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 ...
2
votes
1answer
280 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....
2
votes
0answers
824 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 ...
2
votes
0answers
142 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 : ...
2
votes
0answers
180 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 ...
2
votes
0answers
33 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 ...
2
votes
0answers
186 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 ...
2
votes
1answer
1k views

Pigpio not calling Callback for first rising or falling edge

I have some sample code (taken out of my larger program) that regularly (but not always) missing the first rising edge: #!/usr/bin/python import pigpio, time def callback(g, l, t): print("Callback ...
2
votes
1answer
1k views

RPi Zero: Two UART devices at the same time

I need to read UART data from one device, and send different data to the other device, all via raspberry pi zero. It has only one UART TX and one UART RX on GPIO pins, but I heard that it is possible ...
2
votes
0answers
183 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 ...
2
votes
0answers
158 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 ...
2
votes
0answers
1k views

Permission issue accessing /dev/mem – gpio node-rpio

I am somewhat of a newbie, so please let me know if there is a way I can go about this better. I'm working on doing some LED coding (WS8201 strip) with node.js and it appears I am having trouble ...
2
votes
1answer
80 views

fork() Process Issue on Channel Switching via Rotary Encoder

I have KY040 rotary switcher(encoder) as shown below picture. It is the scenario that there are 5 radio stations(simple html url) in urls.txt which are read into stations list in radyoCS.py, at every ...
2
votes
1answer
1k views

UART pins not reading sensor output RPI3

This is my first pi project so im a bit new at this. Im trying to connect a senseair K-30 CO2 sensor to the pi via the UART gpio pins. This is the sensor I am using: https://www.co2meter.com/products/...
2
votes
0answers
172 views

Simulating electrical inputs to an Arduino and Raspberry Pi

I have an Arduino-Raspberry Pi system, with many sensors attached, that I want to try to virtually test (without either physical device) on Travis CI. Are there any extant tools capable of simulating ...
2
votes
0answers
582 views

Change pin for Wake-from-hold

There is this not-so-well-documented feature about shortening Pin 5 (GPIO3) to GND for booting a halted PI (see e.g. here) which is called wake-from-hold. As it is possible to change almost ...
2
votes
0answers
414 views

Can I control 5050 RGB Strips with the Raspberry pi?

I have purchased 5 meters of a 5050 RGB Strip yesterday. I bought it for my PC case, but of course I don't want to use 5 meters in my case. I want to do some smart lighting in my room and a bias ...
2
votes
0answers
292 views

GPIO Edge detect setup on 3 pins, when one changes all callbacks are called

I have a PI setup with 3 sensors (reed switches) and 2 "outputs" to a relay. They are on pins (8, 10, 12) I have pin 3 setup to drive the first relay and pin 5 setup to drive the second relay. I ...
2
votes
0answers
211 views

Driving a HC-SR04 requires a 10 microsecond pulse, Java does 14. Any success stories?

I'm working on Android Things on an rpi3 dev kit, with the IMHO excellent Picon Zero hat. I'm trying to trigger and read the reply from a HC-SR04, which requires a ~10 μS trigger pulse, then ...
2
votes
0answers
173 views

Best Way To Power Raspberry Pi Zero and External 4.5 - 36v Circuit

I am creating a drone where I have a Raspberry Pi Zero, and a Motozero. I need to supply the Motozero with power from 4.5 to 36 volts as well as the Raspberry Pi Zero. What is the best way to do ...
2
votes
0answers
235 views

multiple DS18S20 temp sensors without using 1wire

Can anyone tell me if it is possible to connect the multiple DS18S20 sensors to different GPIO ports and pull the temperature on different ports, as opposed to a single wire option where I can only ...

1
2 3 4 5
13