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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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After changing lirc gpio wifi stops working with raspbee module attached

I build a tv remote control using lirc on an rpi3, and it worked very fine up to this day. Today I put a ZigBee (RaspBee) module on the first 12 GPIO pins and my output GPIO pin (17) for the remote ...
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How to use GPIO buttons to interact with front end of Nodejs server

So I'm currently trying to make an application that will display columns of data in the browser. I want to be able to interact with what is being displayed with buttons wired in through the GPIO pins. ...
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19 views

creating a .deb package and autorun it [closed]

I'm using a Raspberry Pi 2 Model B running the latest Raspbian Stretch Lite 2018-11-13. I built a program that communicates with a LoRa chip (SX1276) using SPI, gets some data from a temperature ...
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59 views

Burned PI while using GPIO pins

First of all I'd like to point out I already know there a wide variety of posts covering this issue but I'm wondering whether you could help with my case. I was messing around with the GPIO pins ...
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1answer
13 views

Can't trigger GPIO control via executable run through php's exec function

/var/www/html/index.php <?php exec("./on"); shell_exec("/var/www/html/on"); on.cpp #include <string> #include <getopt.h> #include <cstdlib> #include <sstream> #include &...
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1answer
20 views

GPIO solution to power Pi

Looking for a GPIO solution to power a Pi 3 B+. Basically, trying to bypass the Pi micro USB connector. Also, any suggestions on hardware to build a compact, inverted, USB male right-angle ribbon ...
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2answers
19 views

Minimum Pulse Width for asynchronous Interrupt

Does anybody know what is the shortest pulse width that the Raspberry Pi (any model) GPIO interrupt pins can detect? I have a project in mind, but the pulses would be between 5 & 17ns wide.
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1answer
31 views

“push” physical button on a remote

I have a remote for my kitchen fan where I can turn on the fan and toggle to light. This remote says on the back to be using 433MHz so I bought a receiver and transmitter for my Raspberry Pi in hopes ...
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17 views

Raspberry Pi + L293D to switch 12V solenoid valves

I am porting an Arduino project to Raspberry Pi. On the Arduino I switched two 12V solenoid Valves with the help of a L293D IC. It worked perfectly. Now I am porting this system to a Raspberry Pi. ...
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20 views

My rotary encoder is missing pulses - what are some potential solutions?

I have a rotary encoder with a very high resolution (5000 pulses per rotation). I used what I believe to be a fairly optimized rotary pulse counter program written in C found here but the faster I ...
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2answers
50 views

Autostart a program comprising GPIO-commands

I am used to autostart with rc.local, after making my program called "test3.py" executable (sudo chmod a+x test3.py). I failed to get it autostarted, means as the first program which the Raspi-stretch ...
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1answer
24 views

Rapidly-fluctuating output when using rotary encoders with Raspberry Pi + Processing

I'm using a Raspberry Pi 3 with some Cylewet KY-040 rotary encoders that I bought from Amazon to set up an art installation with Processing 3. Pi is just running the stock Raspbian NOOBS. Right now, ...
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42 views

raspberry pi zero audio output [on hold]

I want something like JustBoom DAC Zero pHAT but there are no additional pins for something else. I'm noob in prototyping. What i have to do?
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33 views

I need help coding a toggle button for led? [duplicate]

I have hooked up my circuit and it works as a hold button to turn light on. Then when I let go of button light turns off but I have found no way to make a toggle button for led. If somebody were so ...
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0answers
16 views

Gpiozero inside custom function

So I have a odd problem. I have raspberry pi model 3 using gpiozero in python 3. Just trying to turn on the motor at half speed when calling the function. Issue is that nothing happens when ...
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1answer
31 views

Setting a mode to a pin requires root permissions

I’m trying to change pin mode on RPI (with Raspbian) – it works when I invoke those commands sudo chown root.gpio /dev/gpiomem sudo chmod g+rw /dev/gpiomem but after every restart I have to execute ...
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1answer
43 views

GPIO ports not working

Friends, I try to switch 4 GPIO pins (GPIO.BCM) from '0' to '1', and only the first 2 out of 4 (GPIO18 and GPIO23)do switch, from 0 to 1. I have used different GPIO pins for GPIO24 and GPIO25, ...
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1answer
18 views

Would lifting the pads off of the display and camera connector kill a RP?

Tried to remove some I/O that i dont need from my RP3 A+ to fit in a mobile project. Ive done this before on my RP3 B with great success. But I wasnt to gentle when removing the display and camera ...
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1answer
78 views

How do I run a python script as root [duplicate]

I'm try running a Python script that uses the GPIO pins but I get an error telling me that it doesn't have access to dev/mem and I should try running as root. I don't know how to run a Python script ...
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1answer
35 views

Neopixel lights do not change color

I recently bought a 1 meter WS2812B strip. I installed the Adafruit Neopixel Circuit python library with the following commands: sudo pip3 install --upgrade setuptools pip3 install RPI.GPIO pip3 ...
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1answer
15 views

Lipo power: Powerboost versus Micro-Lipo charger

I'm a hardware newbie, wanting to power my RPi Zero via a Lipo battery, and also have the battery charge without removing it. There are many posts about this, but my question is more about two power ...
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1answer
15 views

which GPIO pins can I use on top of the PhatDAC?

On Pi zero, when I connect switches to GPIO23 and 24 the PhatDac stopped working. PhatDAC is connected to Pi zero by tall header so I connect my switches thru pins. The switches work correctly with ...
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1answer
33 views

Using a molex powered usb panel to power multiple pi's

I have been looking into multiple ways to power numerous rapsberry pi's from one power source. I am not an electrical engineer and as such some methods I have researched online are less than ideal, ...
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1answer
25 views

Making a music device from RPi

I am making a musical instrument from a raspberry pi out of cardboard. It would be like a piano with an octave of notes (13 including sharps). How would I get the raspberry pi to detect when a circuit ...
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0answers
19 views

Raspberry pi 3 - GPIO output stays at 1.8V

I've set-up a GPIO port to output. With an external multi-meter, I've noticed that the potential stays at 1.8V in respect to the ground. I've checked in respect with the same ground, and the 3V3 and ...
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1answer
27 views

Raspberry GPIO button sysfs

I am trying to connect a button to my raspberry pi 3 (model B). I want to do it via the sysfs approach. Here is a picture or my small circuit: It cannot be simpler: the black wire is connected to a ...
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1answer
38 views

GPIO causes random input on room light switch / EMP?

I am building a simple application with a switch on the rasperry pi 3 b+. I have connected GPIO pin 18/32 through a 56k resistor to 3.3v (tried pin 1 and 17) to have it pulled up. The switch closes ...
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4answers
446 views

How can I make my LED flashing while executing the rest of the code?

How can I make my LED flashing while executing the rest of the code? I want to make some LEDs flash while my program executes the rest of the code.
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0answers
6 views

Putting a SlushEngine X LT on a Waveshare High-precision AD/DA board

I am trying to drive a stepper motor based on a voltage (eventually leading to a PID). To do this, I want to stack a SlushEngine X LT on a Waveshare High-precision AD/DA board on a RPi. However, they ...
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1answer
65 views

I did a short circuit between the 5v pins [duplicate]

I thought I could power a fan by connecting each of its rudimentary wires to pins 2 and 4 (5v pins) on the raspberry. Immediately, the screen the pi was connected to went blank, even though the pi was ...
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0answers
30 views

Pi4j Edge detection does not work (always detects both edges)

I am new to using Raspberry Pis GPIO and I am using pi4j to control it. I simply tried to make a Button work, that only triggers when releasing the button. Here is my code if (Gpio....
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1answer
38 views

Can the GPIO pins be used to compromise a raspberry pi?

For example, would a touchscreen device that uses the below pins on a Raspberry Pi 3 be able to do something more than say, send touch and keyboard events? Anything hackish/nefarious? (edit: use case: ...
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2answers
130 views

FM transmitter antenna length

I'm a new raspi user, and I'm starting to build some projects with hardware. I would like to try this FM radio station for example, but I have a doubt about the antenna's length. This is important ...
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1answer
31 views

In raspberrypi 3v3 pin output is not providing power

i am working with raspberry pi suddenly my terminal got stuck and after i dis-connect my raspberrypi and again connect it ;but it not detect my raspberrypi sd card and i found that 3v3 pin is not ...
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0answers
35 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'...
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1answer
30 views

GPIO pin remains high

Upon running the following script my relay stays open when the GPIO pin is set to output. In all my attempts. there has not been any way for me to alter this behaviour. The code I've ran: import ...
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1answer
35 views

How to synchronize GPIO state between two Raspberry over Internet?

What is the simplest way to synchronize GPIO state (states are: 1 or 0) between two Raspberry devices connected via Internet ? What I need is immediately change GPIO state on Raspberry 1 if Raspberry ...
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3answers
59 views

Relay board failing when connected to RPi3 5V pins

I'm using my pi to power several relays. A total of ~20 relays (a 8-relay board and three 4-relay boards) I'm also running home-assistant Yesterday i noticed that when i try to power them all up, ...
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1answer
63 views

Heartbeat on GPIO via config.txt

I want to have an indicator that the Pi is running an wired a LED to GPIO 21 (with a resistor). When manually turning on the LED via /sys/class/gpio the LED turns on. Unfortunately, it does not give ...
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2answers
374 views

MCP3008 analogue digital converter… how can I use it for the complete opposite of what it was made for?

I have set up an mcp3008 chip and a slide pot on my pi because I wanted a nice old fashioned volume control, and all of that seems to working fine and I am quite happy with it. Now I have 7 ...
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1answer
42 views

3 PWM pins for RGB LED

I got an RGB LED, one mass and one for blue, red, green. So I got a list there are only two PWM compatible pins listed. Pin 32(GPIO 12) and pin 33(GPIO 13). But for my RBG LED I need three pins with ...
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1answer
65 views

Connect button to GPIO without breadboard?

Is there a way to connect a button to a Raspberry Pi 3B+ without a breadboard? If so, how? Could you give a diagram and explain? I am only a beginner so please make it easy to understand. Also I would ...
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1answer
46 views

same GPIO input signal on multiple raspberri's from one source

Im having 7 raspberri pi's 3 connected to 7 screens, running an python 2.7 app to download different images from google drive, every raspberry has different images. Geeqie is displaying those images ...
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3answers
72 views

gpiozero Button.when_pressed

I'm learning python and gpio using the examples here: https://gpiozero.readthedocs.io/en/stable/recipes.html I wanted to extend the code to more than one button and pass a parameter to a function (...
2
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1answer
263 views

Green LED on RPI 3B+ GPIO

I have seen a few examples of wiring a red LED directly from the RPI GPIO pins, however, I need to wire a GREEN LED and am having trouble calculating the resistor needed. I believe that a green LED ...
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1answer
32 views

How to use transistor to operate external circuit [closed]

I have a GPIO transistor short circuiting a button on a calculator. I already did the transistor-led projects, but I have a problem: I believe (correct me if I'm wrong) that when current travels to ...
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1answer
27 views

Multiple jumper cables to same GND? [duplicate]

Is it safe to connect the three cables on the right side of the resistors to the same GND on my RPi, or should I put them on separate ones? (I know very little about electronics, but I'm trying to ...
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0answers
50 views

How can I connect the Raspberry Pi to IFTTT without using webhooks?

I know you could use webhooks if the RPI is publicly accessible, but I would like to avoid that. My objective would be asking google assistant to turn on a GPIO pin, then that info magically ...
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1answer
45 views

Connecting Hifiberry Digi+ clone (PiFi Digi+ V1.0) to an Raspberry Pi 1 B (26Pin Header)

Hi I wanted to make use of an older Raspberry Pi and build an Volumio Music Player. I ordered Hifiberry Digi+ clone (PiFi Digi+ V1.0), unfortunately I forgot I own an older Raspberry Pi 1 B with the ...
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1answer
38 views

Wiring Pi - BCM 20 works with a button, but not BCM 21 :-(

I have two switches (buttons). Red is connected to physical pin 38 (BCM 20) and green to physical pin 40 (BCM 21). I call wiringPiSetupGPIO() it returns 0. When I use pullUpDnControl(redSwitch, ...