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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GPIO not working as i want

Yesterday I received my raspberry pi 3 and installed Raspbian. I am trying to use it with this relay, but when i tried to use GPIO using the commands like echo 4 > /sys/class/gpio/export The ...
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3answers
53 views

Generating alternating current from GPIO – is it a misuse?

I've built a simple joystick for my RasPi 3 Model B. When making it, I tried to minimize the number of its GPIO pins, and ended up with a design that uses 3 pins. However, I'm afraid I'm about to put ...
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1answer
26 views

Interfacing PIR motion sensor with Raspberry Pi

I was trying to write a simple Python to detect the motion sensor output and print a message on the screen. My connection was like below: Raspberry Pi model B+ VCC of sensor: 5V (Pin 2) of Pi GND ...
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0answers
24 views

Cascading MAX7219 in daisy chain

For an IoT project I need to cascade MAX7219 in a daisy chain with Pi. Can anyone please assist me with the circuit and the code?
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2answers
31 views

GPIO control relay with button

I'm wondering if it's possible to have my momentary button control a relay in Python whilst I'm holding the button down? Currently, I'm able to control the relay with a small python script, switching ...
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1answer
22 views

PiFm RDS cuts off after a few seconds

I am using my Raspberry Pi as a radio transmitter. I'm using the Pi FM RDS program. It works fine for a few seconds, but then it just suddenly stops broadcasting the sound. The program is still ...
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0answers
19 views

LED connected to Raspberry Pi is always on [closed]

When I connect LED to Raspberry Pi 3, it's always on. It doesn't switch off even when I shutdown the OS. Any idea how can I program it. I used to control via Wolfram language on Raspberry Pi 2 but ...
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1answer
29 views

how do i proceed with SPI on raspberry pi 2?

i am quite new to programming raspberry pi. (though i have used apt-get update and upgrade to install, and i have enabled the SPI mode in the rasp-config) i have recently purchased the arducam mini ...
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0answers
11 views

Problems with ln29 [closed]

Can any help me please . I'm creating a project using the gpio pwm with a ln298 motor controller. I've used this with a small motor but I'm trying to do the same with an old drill motor and 18v drill ...
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1answer
37 views

I²S Pins on Raspberry Pi 3

I looked at the schematics of the Raspberry Pi 3 here but couldn't figure out which Pins are what, to use the I²S Interface. Which Pin-Numbers are for: Bit clock line? Word clock line? Multiplexed ...
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1answer
26 views

Can the L298N be powered solely by the Raspberry Pi 2B?

The L298N shown here has a 12V power input. It also has a dual function 5V in/out. It should be used as input in case power input in the 12V line is below 7V. And it can be used as output in case ...
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1answer
18 views

SyntaxError: can't assign to operator

I'm having trouble programming the logic of 2 PIR sensors to print a message in console whenever a user place both hands on the PIR sensors.I have managed to successfully attach the PIR sensors to the ...
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0answers
29 views

Why do I need to run GPIO as root even with GPIO Ver 0.6.2? [duplicate]

Trying to use GPIO in Python, but it only works if I change to root. Why? The description for GPIO Ver 0.6.2 indicates that root is no longer needed?
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0answers
20 views

Lowering 19v to 3.3v GPIO input [duplicate]

Let's say i need to read an input in a GPIO pin, and the voltage to the input is somewhere near 18V, how would it be the best way to not surpass the 3.3V accepted by the Pi? I've already looked into ...
0
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1answer
18 views

Why do I get an error message: 'Inappropriate ioctl for device' with I2C connection?

I am trying to connect a particle sensor to RPi via I2C. I have added dtparam=i2c_arm=on to the config.txt file and I have also un-blacklisted I2C. Using the Serial Python module, I have a script ...
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0answers
18 views

Pull-up Resistor location on long wire

The DHT22/AM2302 sensors require a pull-up resistor on the data line. Does it make any difference if the resistor is at the end of the wire (for instance on a 6 meter cable) at the sensor vs. at the ...
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0answers
26 views

Connect RFID scanner, Display, WiFi shield, Load Sensor

I'm trying to connect multiple devices to my Raspberry Pi 3 B+. The components are RFID RC522, RPi LCD display, Load Sensor (strain gauge), and WiFi shield. All those are needed for my project. ...
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1answer
31 views

high frequency GPIO sampling raspberry pi

I have a Raspberry Pi 2 Model B and want sample the GPIO 27 with 14400 samples per second. GPIO 27 is a pin with no Uart and no other before implemented funktions, i need the samples as single line. ...
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1answer
32 views

Raspberry PI multiple high frequency pinout

I'm controlling 4 stepper motors with my raspberry PI, and I need to step them in a control loop cycling at a specified rate as low as once every 40 microseconds. The motors won't always be stepped ...
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2answers
80 views

LED Toggle Switch with GPIO

I have a raspberry Pi 3, and am looking to use a 3 wire automotive LED switch (think missile switch or lighted rocker switch) to trigger a GPIO pin, and power the LED when in the on position. If I ...
0
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1answer
11 views

understanding 'close' and 'unexport' of i2c and gpio

I'm learning how to code Raspberry pi in javascript (shouldn't matter for this question) and using the onoff library and i2c-bus libraries. The GPIO (onoff) library shows how to 'close' a pin, which ...
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4answers
63 views

Has anyone found a tutorial on reading info directly from a Kill-a Watt with the Pi?

I keep finding tutorials showing to connect some kind of wireless radio to the Kill-a-watt. I want to find a way to connect the Pi directly to the Kill-a-watt. Is the Pi's GPIO pins not capable of ...
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1answer
24 views

How to turn off / let float a servo attached to GPIO

I'm driving servos attached to GPIO, powered from external PSU and using PIGPIO Library through node.js - everything works just fine but I don't know how to completely "shut down" the servos - once ...
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1answer
46 views

Emulate an SD card with a Raspberry?

I have a special embedded device which has an SD card slot and reads data files from an inserted SD card. These data files are validated only once (because validating them on every access would take ...
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1answer
26 views

Hooking up a speaker to the GPIO

I want to control a speaker via GPIO to play a square wave of varying frequencies. The first speaker I found laying around my house had 4Ω 10W printed on the back. I know for a fact this is not an ...
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0answers
32 views

Raspberry Pi controlling 5v Fan using Transistor [duplicate]

I have a project that requires a fan to keep the Pi cool due to the terrible ventilation. It's a 5v 0.6w fan. So I thought I could use this wiring here: Instead of 12v it would be 5 from a UBEC, and ...
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0answers
7 views

How to adjust sensitivity of Grove PIR module?

I am planning to implement a Motion detection system with PIR sensor of GrovePi+. However I do not know how to adjust the range and sensitivity. Can anyone please elaborate how it's done?
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2answers
46 views

Conveniently devolop Java on my Desktop PC and testrun on Raspberry PI 3

Is there any way to develop Java on my Desktop PC and test-run it conveniently on my RaspberryPi. I'd prefer developing on a more powerful PC, but I'd need to run it on the RaspberryPi due to ...
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1answer
16 views

Segmentation fault while reading water flow sensor

import RPi.GPIO as GPIO import time GPIO.setmode(GPIO.BOARD) #Declaration of pin flowSen1=29 flowSen2=31 flowSen3=7 flowSen4=11 tankIn=12 tankOut=13 cali_flowSen1=4.5 cali_flowSen2=4.5 ...
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1answer
43 views

Processor under high load when using multiple GPIO

Soo here is the thing. I have a script with a function delayedRing(params), which "activates" 3 GPIOs at the same time (or with delay, which is set with parameters), like so: LED1 ON -> delay ...
0
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1answer
40 views

Controlling servo SPEED with either pi-blaster or pigpio

Ultimately I want to be able to control up to 8 servos using node.js - I'm able to control the servos using either pi-blaster or pigpio, but how do I control their speed with which they move?
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1answer
54 views

A guide or layout for the Eleduino GPIO Extension Board Layout?

Does anyone have a guide or layout for the Eleduino GPIO Extension Board Layout? It's a T Board but with 3v/ground and 5v/ground separated on the sides to match with the bread board side lines. It ...
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1answer
21 views

Can two push switches be used as 2 keyboard inputs?

Requirement: I have a custom website which is displayed on a big monitor using a Raspberry Pi. The website has a couple of buttons to navigate around with and I have added JavaScript keyboard ...
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1answer
30 views

Problem with MQ2 Smoke Sensor

I am currently doing a Smoke Alarm System project using Python 3 and a Raspberry Pi. At the moment I am testing the MQ2 Smoke Sensor Code but when running it the smoke level always remains 0. With ...
0
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1answer
36 views

Accessing gpio not working as non-root. “Can't open /dev/mem: : Permission denied”

I am attempting to get a c++ program to access the gpio as non-root. I am on a raspi 2 running Jessie. I followed the instructions on issue: Access GPIO pins without root. No access to /dev/mem. Try ...
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1answer
58 views

Help to build Mini PCI-E add-on card for Raspberry Pi 2

Is it possible to build an add-on card that has mini PCI-E slot, SIM slot and LED and that can be attached to Raspberry Pi 2 GPIO header? It would save me one USB port and it would be more neater ...
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3answers
97 views

What can I use GPIO pins for?

I have completely no idea what they do, except for the part that they can be used to control LEDs and then the Pi camera Are there any practical/simple uses for it?
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1answer
40 views

Connecting multiple devices via I2C

http://www.modmypi.com/raspberry-pi/breakout-boards/adafruit/adafruit-pwmservo-driver-16-channel-12-bit-pca9685 How do I connect two I2C devices to my R Pi? Specificaly 16 Channel 12 Bit PWM Servo ...
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1answer
24 views

unable to set GPIO 17 as an output by assembly program

I am trying to st GPIO 17 as an output. I am using Pi 2 model B. By searching for the base address of peripherals, I found that it is 0x3F000000. I want to write a code in assembly language, Following ...
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3answers
23 views

Sharing ground with the outlet power source

So, here's the theoretical setup: 220V outlet to which a 5V USB power source is connected, powering the RPI. That outlet powers some other 220V consumers (such as a lightbulb). Lets say I have a GPIO ...
0
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1answer
30 views

saving GPIO data to sqlite using python, retrieving dynamically using php

I am try to make a game for my son, it has 2 vibration sensors that represent Balls and Strikes (for baseball). When a sensor is hit I have a loop that adds a tick to either the strike or the ball. ...
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0answers
10 views

Line passing via XBee and timeouts

I'm trying to control a few lights on a sign that will be a short distance from a Pi 2 via an XBee 802.15.4 with IO line passing. Everything works, except that 25 seconds after a change, the sign ...
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5answers
2k views

Why do the Pi GPIO pins use/give 3.3V and not 5V?

I know for a long time that people should NOT put more than 3.3V on the GPIO pins. They also give out 3.3V when high. Cue weed jokes I did some research and it seems no one really bothered asking. ...
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2answers
52 views

Why raspberry has 5V output rail if gpio only works with 3.3V?

I have recently read that using Raspberry GPIO with 5V is risky as it may damage the GPIO pins. I did used my Raspberry with 5V without knowing this fact and I was lucky that sensors I have used were ...
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1answer
42 views

How to communicate with a raspberry pi cube satellite?

I am planning to build a cube satellite that will be above 150km - 600km altitude in the LEO(Lower earth orbit). What can i use to communicate with it. How would that work? I know I will need a radio ...
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1answer
36 views

How can I put GPIO.HIGH in a variable

I have a python program what control relay board via GPIO. When I set a GPIO port LOW the relay closes and HIGH opens the relay As example. I use this line to close the relay and open it again after ...
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1answer
212 views

Trying to use PiGRRL 2.0 Custom Gamepad PCB but there's no documentation on how to program the buttons

I have this gamepad PCB from Adafruit: https://www.adafruit.com/products/3015 In their guide it's supposed to work with the file they give you but that image only works on raspberry pi 2 and I'm ...
0
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1answer
32 views

Access GPIO Pins in OpenELEC

I want to use the GPIO Pins to controll a 433Hz transmitter on a pi 2 with openelec. It is possible to use ssh, but I am not able to install the software (Commands are in description: ...
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0answers
31 views

What component do I need to play a sound clip over GPIO?

I'm looking for a way to play a sound clip (wav/mp3/ogg) using the GPIO and some small component(s) (i.e. not ordinary speakers). The sound clips contain human speech, so quality need not be great. ...
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0answers
21 views

Most efficient way to play music with floppy drives

I've been wanting to use my RPi as a controller for a floppy drive symphony for a long time. However, progress is going very slowly because I keep running into issues. Whenever I try to use more than ...