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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Why does a GPIO pin float? [on hold]

If the GPIO pin is connected to a 3.3V source it goes high. If the the GPIO pin is connected to nothing it is maybe low or maybe high, ie. floating. But why then is it not definitely low?
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18 views

Blinking LED - start and stop

This is my first post here so HELLO and sorry if I'm posting in the wrong place. Do you know a simple bit of Python that will set a LED blinking indefinitely until it's told to stop? Control will be ...
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1answer
31 views

Connecting 32 pin LED matrix to Raspberry Pi

I have a Raspberry Pi Model A and a 32 pin 8x8 full color LED Matrix. I would like to connect these up so my Raspberry Pi can control all the LEDs. This is the LED matrix I have: ...
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38 views

Using gpio value [on hold]

Is it possible to reference the value of the pin 7 outside this function in a global variable? gpio.setup(7, gpio.DIR_IN, readInput); function readInput() { gpio.read(7, function(err, value) { ...
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1answer
68 views

Rasberry Pi IR Transmitter does not work

Config directory root@raspberrypi:/etc/lirc# ls hardware.conf lircd.conf lircmd.conf lircd.conf file # Please make this file available to others # by sending it to ...
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14 views

Can I use the GPIO pins of a Pi Zero to control stepper motors? [duplicate]

I would like to control two stepper motors using a Pi Zero. I'm pretty confident that this is possible (please, please, please tell me if it isn't!) but I have no idea where to start. Is there any ...
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1answer
32 views

Why do I need to connect servos to the ground of the battery and the ground of the RPi?

I'm trying to use two servos simultaneously and I've connected both servos to my battery pack which gives 6V (the servos require 6v). If I ground the servo only to the battery and I only use one of ...
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1answer
28 views

Configure Alt GPIO using sysFS

I have a Model B Revision 1.0 + ECN0001 that I am making a program in C to read and control a HCTL-2022 Quadrature Decoder using the GPIOs by way of sysfs. It's working great, but now I would like to ...
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1answer
31 views

Doesn't having pull up resistors in the I2C pins disables their use as GPIO?

The GPIO 2 and 3 pins are the I2C pins and both have 1.8k pull up resistors. Can they still be used are GPIO pins even with these resistors?
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33 views

How to connect a servo feedback potentiometer?

I've taken apart an old RC car and have been trying to get my Raspberry Pi to run the car. At this point, I'm able to control the rear drive motor. The motor is connected to a L298N H-Bridge module. ...
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3answers
37 views

Is the GPIO configuration changed for Raspberry Pi Zero

When I wanted to start working with Raspberry Pi Zero, I presumed the GPIO configuration is the same as for A+, B+ and Pi2 and I wanted to confirm it is true. However, I couldn't find an official ...
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1answer
543 views

I need to control 8 LED's but I can only control 3? [helpful pictures attached]

I'm very new to electronics in general, but I want to build a small project where I can individually control (from a GPIO pin) 8 LED's. From what I understand, each GPIO pin on the Pi (Pi2 model B ...
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1answer
19 views

How to use the Display - O - Tron 3000 with the hc-sr04?

I've got a Pimoroni Display-O-Tron 3000 and a HC - SR04 ultrasonic sensor. I want to use the Display to output the distance that the ultrasonic sensor reads, however, the DOT 3000 uses all the 5v ...
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1answer
95 views

GPIO True and False seem to be reversed

I'm using the GPIO pins on my Pi under Raspian to control a relay and a computer fan. In Python 2, the command GPIO.setup (18, GPIO.OUT) Immediately supplies power to the pin and triggers the ...
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1answer
70 views

Is there a way to add power button on RPI 2 Model B? [duplicate]

Me and my dad were been looking for making small Pi to bigger Pi out of old PC case from 2004. So I thought that I need power button to power Pi but it's in the PC case so I took those but then i ...
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0answers
39 views

what is required for automation in plantation? [closed]

What i want to do is when the moisture of the soil gets decreased i just want to give water to the plants or if i can just get a notification about the moisture would be fine. I have very little ...
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0answers
87 views

RPi 2 isnt booting, Green and Red light ON

I have Rpi 2 model B v1.1 for a week. I tried some cirquits with GPIO pins. One day i made a simple button cirquit. It worked well. But few minutes ago Rpi crashed, i powered it off. When i power it ...
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1answer
334 views

Common ground with 9V?

I'm new to pi's extending. I've a MB102 breadboard, coupled with a powersupply. I plugged a 9V power supply, and it's working (powersupply => resistor => led on). I'd like to interface some ...
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4answers
98 views

How to connect a graphic card to Raspberry pi?

I want a way to connect a graphic card like nvidia or amd to raspberry pi do you think has a way to do that?
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29 views

Direct memory access GPIO address manipulation

So we have a structure that is composed of pointers to the already mapped memory area. struct bcm2835_peripheral { int mem_fd;// "/dev/mem"s file descriptor void *map; //pointer to mapped ...
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0answers
4 views

What is an active bounty? [migrated]

What is an active bounty? Please explain. I am a new Pi user and don't have a clue what is being asked of me. What are your quality standards?
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1answer
114 views

GPIO stuck in High Mode

I'm new to this whole RP world, and I'm trying to learn it. I've been trying to follow this post, and connected my Pi this image below Connection between Pi and Adafruit T-Cobbler Plus Wiring ...
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1answer
40 views

Can't turn off gpio pins

I recently installed raspbian on my RPi and i have experience in Python so I decided to play with GPIO pins. As soon as i connected my led to the 4th pin(5V) and 5th pin(GND) it turned on and I ...
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13 views

How to make a python program start when the Raspberry Pi boots up with Raspbian? [duplicate]

For your information, this python program requires root privileges due to needing to control the GPIOS. Any help would be great.
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1answer
58 views

How to add a fan to the Pi

I was reading about how to cool the raspberry pi, I plan to do so, however, some articles mentioned that I should use a buffer circuit rather than connecting it directly into the GPIO pins. What does ...
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1answer
58 views

Are there any practical benefits to using a U-cobbler vs. T-cobbler and vise-versa?

I just bought a Raspberry Pi 2B and am now looking at accessories for prototyping some electronics projects. From what I've found, it appears there are three different styles of cobblers that make it ...
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1answer
35 views

Is there a possibility of GPIO failure?

I made my GPIO working as I want, but is there a possibility of GPIO failure after some time? My raspberry will work 24/7, GPIO pins will be used for like 20 minutes a day and I'm wondering if I ...
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1answer
38 views

Allow sudo only to run one Python script that accesses GPIO

I have a simple Python script that controls three LEDs. I want to limit the sudo command for my user counter (member of group pimem) to just run this script and because it access the GPIOs also allow ...
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2answers
36 views

RPIO Module installation

I've been trying to install the RPIO module onto my pi. so far, no luck because my pi is without internet at the moment (I only have internet on my laptop through mobile tethering). Does anybody know ...
4
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1answer
68 views

Windows IoT on Raspberry Pi: how to eliminate huge variations in reading pins values? (C#)

I have been porting the library for HX711 (Weighting sensor module amplifier) for Arduino to C# for Raspberry Pi Windows 10 Core. Source here on GitHub Arduino library It does work, I am even using ...
3
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2answers
52 views

Project needs multiple PWM

I'm working on a project that needs three (or more) PWM pins to work. But unlike Arduino, the Raspberry PI B+ has just one PWM pin. I've searched for solutions and I found that I can use the WiringPi ...
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25 views

High frequency data reading from Raspberry

Is it possible to organize the reading of data from GPIO with high and precise frequency (up to 200 kHz) in win10 IoT?
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9 views

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

This is the surprise that I saw when I booted my Raspberry Pi B+. In case you can't read the picture, it says, sh: can't access tty; job control turned off. When I try to go into a different virtual ...
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1answer
34 views

Switching a Circuit on/off with a MOSFET

I have have a simple circuit that I want to drive with a raspberry pi GPIO pin and I want to use a MOSFET to control the circuit. My circuit will be using about 3-5v and 2-3a. I'm planning on using ...
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2answers
121 views

How To Switch On/Off A Circuit using GPIO

I have a simple circuit that runs on 5 volts. Let's just say for simplicity that it is a circuit with an LED that lights up when a push button is pressed. The problem is that it has a push button ...
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1answer
88 views

What are the limitations of PiZero GPIO?

PiZero does not seem to have conventional GPIO pins. How to use GPIO?
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2answers
455 views

GPIO library for C

I want to utilize the GPIO pins on my Raspberry Pi 2, but I'd rather not use Python since I personally dislike the language. However, I cannot seem to find any information regarding the use of C, only ...
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1answer
48 views

Raspberry Pi 2 As Inbetween From GPIO Device To PC

So I'm not sure if this specifically has been asked before, as I had a look around, and most of the questions relating to USB stuff seemed to be about using the Pi as a USB flash drive. I was ...
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3answers
247 views

How to know the input voltage on Raspbian?

I have a unattended raspberry with a power supply for many device. Raspberry has lately restarts and I think that may be caused by a under voltage. Is it possible to check the input voltage for ...
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1answer
42 views

Sequential Control - time and signal based in C

i want to program in C a simple sequential control with the raspberry. The current task is: If a button is pressed, something (e.g. a LED) shall be switched on for 5 seconds and then go off itself. ...
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4answers
69 views

Set up RPi2 as a local website for I/O control

I am making a drink making robot. I was going to set the RPi as a webpage that can only be accessed when on my local Wifi network. Then on the page you would select what drink you want and when the ...
0
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1answer
39 views

Sensing soil moisture levels with the RPI - ADC/GPIO & ADC/USB solutions anyone?

I bought a 'Soil Moisture Sensor' like this https://www.tiagoespinha.net/wp-content/uploads/2014/05/2014-05-09-12.51.20.jpg from ebay, and it turns out it's really nothing of the sort (just a ...
5
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1answer
121 views

GPIO callbacks in any language

I know the linux kernel has a language agnostic GPIO interface through /sys/class/gpio which can be manipulated with echo, cat, etc. How can this be used to create event driven callbacks ...
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1answer
134 views

Pi GPIO to another GPIO?

Would it be possible to connect one gpio directly to another gpio, and use one as input and the other as output on the pins? Then I could just supply power to one of them and run them both headless. ...
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1answer
19 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 ...
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1answer
33 views

WittyPi board keep turning off Raspberry

I have a Raspberry connected with the WittyPi board. Been strugling to get it running without it dead locking. I have followed the steps in Witty Pi's manual ...
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59 views

Is the resistor needed to connect 3 pin 5v buzzer (RP2b)?

I am new to Raspberry Pi. I recently wanted to connect a active buzzer (5V 30mA) like this: BUZZ to my Raspberry. I am not sure should I use a resistor on the way to +5v pin and DATA GPIO pin. (like ...
3
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1answer
36 views

Unknown fuse blow out in custom power board for raspi B cluster

I've been trying to adapt the design for power distribution layed out in this raspi cluster design. . While looking through the researcher's design, I couldn't find any use for jumpers 2 and 3, ...
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1answer
73 views

Raspberry Pi 2 B GPIO pwm and interrupt pins

Good day! I would like to use pwm and interrupt on raspberry GPIO pins but i don't know which GPIO pins are actually dedicated for pwm output and which is for hardware interrupts, is there a way for ...
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1answer
36 views

Raspberry Pi IR Sensor stays HIGH when it shouldn't

I have a Raspberry Pi that has an IR sensor on it, and a Arduino that has IR LEDs hooked up to it. I am sensing when something is put into a box, but not when the item is taken out (callChris() is ...