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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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HD44780 Display and wiringPi

I have wired a display to the raspberry pi, which uses an HD44780 controller. The wiring was verified by using this python script: https://www.raspberrypi-spy.co.uk/2012/08/20x4-lcd-module-control-...
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I can't change pin value

I've been with my new Raspberry for a month and it worked perfectly but today the pins have stopped working. I have tried many ways to put them with value 1 but for more I try not change them from 0. ...
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Is it possible to revive GPIO 18 pin? [duplicate]

I guess it (pin 18) got burned after me accidentally connecting it to the 12V of the led strip and not the data pin, while the RPI ground and 12V ground were connected too. I used pigpiod, gpiotest ...
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GPIO only reaches 2,4v when high

TLDR; Under little load the GPIO 22 reaches 3,5v whereas under more load it only reaches ~2,4V, which is not enough to trigger the reset-line on an ATMEGA328P. UART GPIO Pins still reach 3,3V in both ...
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Emulate USB devices from one Pi zero to another Pi zero

I'm looking for the best way to emulate USB devices that are plugged into a Pi zero and connected to another Pi zero through GPIO pins, so the second Pi zero will emulate the actual device that is ...
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27 views

Use Python flask or NodeJS for controlling stepper motors via Web?

Im planing a project where I need to controll some stepper motors with my RaspberryPI. I'd like to controll those motors interactively via a web GUI. This server should run on my Py. Now I found a ...
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How to connect a pulse sensor to my Raspberry PI 2?

I have a pulse sensor looking like this, having three outputs: _____ / \ | <3 | \_____/ | | | I assume it is the same model like sold on pulsesensor.com, but I bought it from an ...
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52 views

Ultrasonic sensor stops working a few minutes later

I want to get distance continuously using while loop but a few minutes later my code suddenly stops working and doesn't get distance (there is None value in distance variable) I have changed first ...
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32 views

5 volt GPIO pins on RPi not working?

So, today I made a simple LED circuit with a 5 volt pin on my Pi and it doesn't work. I tried the 3 volt ones and they work, but every 5 volt pin fails to work. The circuit just consists of a red Led,...
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Sending Data from LoRa connected to Raspberry Pi

My objective is to connect a LoRa module with RPi and send data using it. So I made the connection:(Rpi to LoRa) 3v3 (Physical Pin 1) to Power Source (Pin 1) Tx (Physical Pin 8) to Rx (Pin 3) Rx (...
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Interrupts with MCP23017 using the mcp23017 dtoverlay

I'm at my wits end with this one. Okay, so we've got an MCP23017 with its INTA wired to the Pi gpio12 (bcm) in /boot/config.txt dtoverlay=mcp23017,addr=0x20,gpiopin=12 so far so good. I'm looking ...
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unwanted wake from halt

I want to use the "wake from halt" with my raspberry pi to keep it down must of the time and waking up using external stimuli when need. But I am not sure why, sometime it wakes up from halt although ...
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22 views

Connect Raspberry Pi to access controller Z-5R by GPIO

I try to understand how to control Z-5R. Z-5R - it's access controller, that control the electromagnetic lock by RFID cards. I want to control this device by Raspberry Pi. How I can plug it correct? ...
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25 views

KY040 Rotary Encoder not responding at all

Hey I'm very new to raspberry pi and decided to start a mall project including a rotary encoder. I found some guides online that I followed but I just can't get any signal from the encoder ...
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473 views

How can I wire a Raspberry Pi to an 8-relay board in a tidy professional manner?

I want to connect a Raspberry Pi to an 8-relay board, such as this one. Together with ground and power this amounts to ten wires. One option to connect the two is by using female to female jumper ...
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18 views

Control GPIO from HDMI V sync

My Project on a Raspberry Pi 2 with Raspian stretch. I want use a GPIO pin to drive 3d shutter glasses (glasses hacked to receive 0 _3V square wave) Video playing on the HDMI port and A Pin goes on ...
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PiCamera Minimal latency between real world event and digital data presence

Using a picamera, what is the best latency one can achieve from a real world event like an led lighting up and the Pi/MCU 'knowing' it has occured(by extracting image data)? I would also be ...
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How to toggle a 1 Channel Relay 5V

So. I have a 1 Channel 5V relay from a starter kit and I cant turn it on or off. I saw a bunch of tutorials but in every one the labels on the relay are such as VCC, GND and so on. My relay its ...
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Closing Circuit versus voltage

I want to control this remote in the picture using GPIO. Am Newbie. I followed a cookbook to connecting the relay directly to the garage door motor but thought "Why not use the remote and perhaps ...
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2answers
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capture Image with picam then send to another pi via UART

I would like to send an image(JPEG) captured by a pi-zero (in a in-closed container) to an pi3 for storage and analysis. Currently I have UART via gpio set up, but so far I have only been able to send ...
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42 views

What is the highest amount of relays Pi 3 can handle?

I'm looking to do something interesting with 16-20 laptop and computer fans. I was wondering if this was possible to just connect them to a large battery and then use a trigger to control some power ...
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Blink project mishap, help?

So I've set up the blink experiment using my newly bought electronics kit for my RPi 3B+ (https://www.amazon.de/Freenove-Raspberry-Processing-Tutorials-Components/dp/B06VTH7L28/ref=sr_1_3?ie=UTF8&...
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Erratic motor behavior from a Pi being controlled through a websocket

I'm in the process of trying to put together a small "robot" that can be controlled over the internet. I'm trying to get the code for the drive motor controls down now, and I've hit an odd issue. ...
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1answer
23 views

Use internal pull up resistors with the gpio-keys module in the device-tree

I have an external board with some buttons that are attached to gpio 20 and 21 which connects these pins to ground when pressed: simulate this circuit – Schematic created using CircuitLab I'd ...
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Connecting a PIR and Relay Module to a Raspberry Pi causing 2 Minute False Alarms

I am building a small home automation system, and one node has a PIR to detect motion, and a Relay Module to control a 240v light with a Raspberry PI 3. The PIR is connected to 5v, and has a ...
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Change UART default pins

On of on my pi zero I think my RXD pin is out. When trying to connect through usb/serial I receive all the loading of the boot and the login console but cannot send anything (thus cannot login). I ...
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38 views

Read data from a balance via RS232 port using rs232 to usb converter cable in rapsberry pi

I am a beginner to this, I have a balance (scale) that I need to read the data (weights of material) from. Data will be read every 10 seconds and I have looked up RS232 codes in here and utilised ...
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1answer
28 views

Connect raspberry pi to an iphone app without port forwarding

For our capstone project, we have a python code that is supposed to detect the presence of a tile beacon, then we want that program to communicate with an iphone app built with swift letting it know ...
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1answer
56 views

GPIO not fast enough for RF transmitter?

I'm trying to control a 315MHz RF socket using the RCSwitch library. I tested with an Arduino and it worked 100% of the time but when porting over to a pi zero I can only get it to correctly turn on / ...
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2answers
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Channeling a single circuit into 6 possible circuits based on gpio pin signal

I basically want a single input relay, with 6 outputs, that switches to any of the 6 outputs based on the gpio signal, if that makes sense. So the gpio signal would send a signal like 1-6 in binary ...
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can I use SSH and GPIO UART simutaniously?

I am connected to my Raspberry PI 3 B+ running Raspbian through an SSH terminal, and I am trying to make an application that uses the UART through the GPIO. Whenever I try to open the port "/dev/...
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GPIO in /sys/class/leds/

I am doing a project with Raspberry Pi and OpenWrt. I need to attach indicator LEDs. Basically, I need to modify the DTS for bcm2710 and add additional GPIOs in the led section such that it gets ...
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Pigpio Wiegand timeout

I have an RFID keypad linked to my Raspberry Pi. It sends out a Wiegand 26 signal when someone presses a key or presents a card/fob. The code is based on http://abyz.me.uk/rpi/pigpio/examples.html I ...
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56 views

How to control 12V LED with the GPIO?

Heyo! How to control single 12V LED using Raspberry's GPIO? To be more exact, I need to connect 12V LED & push button to Raspberry Pi 3 B+ GPIO in order to control LED (on/off) and read button ...
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56 views

Start / stop a script with buttons

i want to start and stop this script with a buttons 1 button to start and one to stop using gpio pins 35 and 37 #!/usr/bin/env python from random import randint import SimpleMFRC522 import time ...
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42 views

anode RGB LED to raspberry Pi

I have wired up a common anode rgb led to my raspberry Pi. I dont understand why its not lighting up. My setup is this: 5v to rgb anode rgb to pi pins ( 5,6,26) My code is const Gpio = require('...
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Controlling a led button and receiving input from that button

Ok, I have a button with a small 24v Led inside. My goal is to control the light depending on the state of the button. Quick press: toggle start/pause --> light on/off Long press (1500ms) --> reset -...
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1answer
33 views

Python RPIO.ChangeDutyCycle() Equivalent in WiringPi (C)

I'm currently developing an application with the WiringPi library. I have implemented a prototype in Python, and I'm currently trying to reproduce the same behaviour in C++. However, I ran into some ...
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1k views

Why do LED lights need resistors? [duplicate]

Can someone explain why LED lights need resistors when connecting to pi. The raspberry Pi is either providing 3.3v or 5v depending on if it's connected to power pins or gpio pins. Your set up would ...
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2answers
42 views

How to know if Raspberry is running

I'd like to implement an electronic circuit to be able to restart my raspberry Pi when it has been shutdown (without plugging in and out the USB charger, which will obviously remain plugged all the ...
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1answer
22 views

Pi Camera streaming via gpio

is there a way to transfer the video stream from one raspberry pi to another via gpio pins? One pi is In a closed container with the camera and the other pi drives the user interface. Networking is ...
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1answer
41 views

Generating fast rise PWM signals using software GPIO

I want to use my Raspberry Pi 3 Model B (rev 1.2) as a source for fast rise PWM signal generation. The idea is to utilize RPi as part of a cheap TDR (time-domain reflectometry) setup. For anyone ...
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1answer
39 views

Read/Write GPIO

I wrote an assembly code for my Raspberry Pi to read an I/O with a button and switch an LED according to the state of the button. It seems that the I/O with the LED is toggling all the time and I don´...
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34 views

piscope SPI pin activity even though the SPI device is not connected

my final goal is to use python (spidev) to communicate with a BMS chip. Until now I was quite unsuccessful, thats why I wanted to use piscope to track the activity of the SPI pins. The device is not ...
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how do I assign pins on GPIO expander mcp23017 to a 2nd i2c bus

So I've got a device on my pi that takes up almost all of the GPIO pins on the pi, but the device nicely has an MCP23017 on board, giving me an extra GPIO pin, number 496 - 503 What I want to do is ...
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DS18B20 & Pi 3+

I'm not getting a w1_slave, and all I'm getting is 00-xx0000 when the DS18B20 isn't burning my fingertip. I went for green for ground, which is on the top right plug from this perspective. I spliced ...
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1answer
33 views

enable software i2c on raspberry pi gpio

I am trying to interface more than one sensor with Raspberry Pi Zero W, which communicate using i2c interface. So far I am able to connect sensor to dedicated i2c and read the data. Want to know ...
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ReSpeaker 2Mic Expansion Board Not Showing Up Under “aplay -l”

I am very new to the raspberry pi. I am setting up the Respeaker 2Mic Expansion board on my Raspberry Pi 3 B+. I have downloaded the files from GitHub through the terminal, have physically connected ...
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Raspberry Pi 3 B+ LED Light Blink not working

I am trying to get my LED to blink once, but it is not working. I connected the brown wire to pin 6 (Ground), and the red to pin 7 (GPIO 4). I watched a tutorial on connecting the circuit but it is ...
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Is it possible to plug in and out sensors, LED-s etc. on the breadboard while the Raspberry is running?

What I would like to do, is to let the Raspberry Pi run and while it is running, connect and disconnect eg. sensors whenever I please to/from the breadboard WITHOUT turning off/disconnecting the Pi ...