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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How to get LDR sensor reading in C language [on hold]
I am currently working on a project using laser module, a capacitor and an LDR. After looking online, I found a library in Python called GPIOZero that allows me to do this directly, as follows:
from ...
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1answer
36 views
Why is pigpio library not moving my servo when the same pin number works perfectly with RPi.GPIO?
I am working on a self driving rc car project and I need a servo to steer my car. As I was getting a bit jitter with RPi.GPIO I tried pigpio library. I am using a Raspbery Pi Model B. But it won't ...
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2answers
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Voltage dropped significantly on GPIO 4 with a relay coil
I have a Raspberry PI 3 B+, and when I activate the GPIO 4 as output and checking agains a multimeter I get its 3.3V as expected.
If I connect the GPIO4 to one end of a coil (http://www....
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How does the linux kernel handle interrupts [on hold]
A few days ago I asked a question that had (probably) had to do with en interrupt being fired by an ENC28J60 chip (SPI) and messing with the UART buffer. See here.
I found a software fix for this ...
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34 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'...
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Is it possible to toggle 3.3V and 5V header pins on and off? [duplicate]
Header Pins 1, 2, 4, 17 are labled 3V3 and 5V on the schematics but the connections to the BCM and/or regulators are not in their documents. It appears the 5V node is coming from the raw USB/external ...
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26 views
False Contact Closures - Do I Need Physical Pull Up Resistors to Resolve?
I'm running Raspbian Jessie 4.9.35-v7+ on a Pi 3 Model B. I cobbled together a basic python script to monitor a GPIO pin and send a network signal to a remote application, made two copies of the ...
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1answer
23 views
Raspberry pi and microbit working together
Can I do a pin out from raspberry pi onto a breadboard and have a microbit setup to receive that pin out and have the microbit run a command on pin in?
Or can I have the raspberry pi send a signal to ...
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2answers
29 views
Can't exit my apllication in a clean way
Not sure if my problem is related to RaspberryPi, GPIO or just my understanding of Python but since I'm detecting my problem while playing with a button attached to my PI I ask it here.
I have a ...
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1answer
19 views
How to control computer fans with GPIO
I want to build a smart air conditioner with my Raspberry Pi 3b+ by using these PC Fans: https://www.amazon.de/Arctic-F12-PWM-PST-Geh%C3%A4usel%C3%BCfter/dp/B00NTUJTAK/ref=cm_wl_huc_item.
What is ...
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Reading Bytestream from GPIO / External Interrupt and CLK
So I have an external device which bangs out a byte stream (DOUT), it indicates the upcoming stream on an DRDY. The timings are given on an DCLK line.
These three lines (DRDY, DCLK, DOUT) serve the ...
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1answer
139 views
Reactive Programming
The examples I see for the GPIO input are based on a loop which waits and check if the GPIO is receiving any info. Is there a way of just detecting when a button was pressed without using a loop under ...
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2answers
67 views
Run the program in the laptop and use the raspberry gpios
I'm working with face tracking and I want to activate some servomotors depending the motion of my face. For facetracking I'm using, an usb cam, opencv and dlib.
Now results the raspberry can't run my ...
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0answers
20 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 ...
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1answer
22 views
Is it possible to use BCM 3 for IR Remote Receiver?
I have connected an IR remote receiver to my Rasberry Pi's GPIO BCM 3 on.
The receiver works as expected and I have the wanted side effect, that if off as soon as an arbitrary key on the remote is ...
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1answer
23 views
How can specify unsigned number corresponding GPIO pin in linux kernel module?
I am beginner of linux driver. I want to write my simple module with led. i found some function like gpio_request(unsigned gpio, const char *label), gpio_export(unsigned gpio, bool ...
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1answer
58 views
outb() equivalent in Python for GPIO
I am a very beginner on programming and raspberry usage, tho I think I learn fast. I am trying to convert an old program (not mine) that was written for Linux on C++ for communication with a printer ...
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1answer
62 views
Thoughts on emulating a ROM chip with a Raspberry Pi?
I am reverse-engineering a late-'80s IBM Wheelwriter typewriter, which runs off of an Intel 8088. It has a ROM chip, specifically: https://www.datasheets360.com/pdf/1277907997291200345?xrefPartId=...
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1answer
43 views
128x64 OLED Display Issue [closed]
I have a cheap display I got from eBay connected to a Raspberry Pi B+. It has 4 pins (vcc, gnd, scl, sda). I followed the adafruit tutorial here but after setup, when I run a python example (any of ...
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2answers
84 views
GPIO pins do not appear to go into the raspberry pi
I am testing out this new birthday present I got ages ago and I this set I have got has got male pins and the raspberry pi's GPIO pins are male as well and they obviously appear to not go in.
This ...
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3answers
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GPIO to detect if external 5v source is turned on or off?
I'm using a Pi Zero W and I'd like to connect a 5v source to a GPIO pin to detect if the 5v is on or off.
I know the GPIO is only digital I/O and 3.3v max, so is a simple voltage divider enough or do ...
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1answer
60 views
Using GPIO between two radio programs
So I have two programs that are meant to talk to radio's via GPIO pins but need them to talk to each other via GPIO
Eg..
Program 1
PTT = 12
COS = 16
Program 2
PTT = 16
COS = 12
So basicly when ...
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0answers
22 views
PiFace Digital2 and LED display
I'm building a home alarm system with Raspberry Pi 3 B+ and the PiFace Digital 2 board.
I will have used all 8 inputs, and maybe 4 outputs.
Now, my question is, If I would like to connect a 16x2 ...
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1answer
50 views
WittyPi on Pi Zero W - I2C read / write fail
I've connected WittyPi2 (an RTC Power Management hat) to my Pi Zero W - but I'm constantly getting failures in the log, to do with the I2C communication:
I2C read 0x01 0x68 0x09 failed (result=), and ...
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1answer
79 views
LIRC won't setup the device
Very new to this low-level driver stuff, so many places to make mistakes.
Basically I'm trying to get an IR transmitter with lirc. I have a IR led to pin 23 with a transistor, however there's nothing ...
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1answer
31 views
Value of GPIO in a slider buttton changing without doing anything
I want to use a slider button of 3 pins.
Actually I'm using 2 of it, like the schematic below:
simulate this circuit – Schematic created using CircuitLab
My code is:
import RPi.GPIO as GPIO
...
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1answer
33 views
connect 4 measuring devices output to a raspberry and set a Pin high if value exceed a particular value
I have a special measuring system. Each measuring unit gives PWM output (total 4 outputs). Maximum frequency will be 10Khz (for each output). I wanna measure the frequency of each PWM evey second ...
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1answer
27 views
Changing between I2C and GPIO in the same application
My program is a test system. It should first set SCL=1, SDA=0. Read some values from other GPIOs. Then set SCL=0, SDA=1. Read some values from other GPIOs. This is in order to verify the integrity of ...
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1answer
90 views
Any way to add more GPIOs to the AIY Voice Kit?
I'm working on a project using the google AIY Voice Kit V2 as a base. I'm planning on adding a keypad which requires 12 GPIOs. Does anyone know of a way to add more GPIOs to the Pi Zero W with AIY ...
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3answers
41 views
Turn on 2 leds with a toggle switch
I have a toggle button with 3 pins. I want to use it to turn 2 leds, when it's in one position turn on one led (red) and when it's in the other position turn on the other led (green).
I found a lot ...
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RFSniffer and Transmitter program for 434 mhz receiver and transmitter
In the past, I have successfully build a solution to control my etekcity smart plugs working on 433 mhz using the RFSniffer and transmitter ( RFOutlet ) etc. programs.
Currently i am trying to ...
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1answer
29 views
How Can I Determine Why My Python Script Is Terminating?
I'm running Raspbian Jessie 4.9.35-v7+ on a Pi 3 Model B. I cobbled together a basic python script to monitor a GPIO pin and send a network signal to a remote application and made two copies of the ...
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4answers
82 views
program my robot with python
initially my question was about how to fix my code. You informed me that usage of that python class will not work with my setup of one motor. I agree and I want to instead use the GPIO library to ...
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2answers
166 views
Water Level Detection Sensor 3.3 Volt vs. 5 Volt
I'm using a classic Water Level Detection Sensor or sometimes called Rain Water Level Sensor together with a RPI 3+ to detect water in a Pot (Link).
So I don't need any analog reading but only the ...
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3answers
111 views
Multiple GPIO Buttons
I've seen a tutorial here that shows me how to do this:
But what I want to do is like this:
I want to have multiple buttons and distinguish between them. The graphic I painted depicts the desired ...
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1answer
65 views
Raspberry Pi 3b+ do not detect DS18b20 on 1Wire
Problem: The new raspbian kernel does not detect the DS18b20 sensor over the 1wire bus. This is due to the Device Tree that was added to Kernel 3.18.8
What hardware used:
Raspberry Pi 3b+ Kernel: 4....
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2answers
28 views
Is it possible to change Rx pin as GPIO15 is damaged?
I rather stupidly connected 5 V logic directly (without using a level shifter) to Rx, GPIO 15 (pin 10), of my RPi 2B and now it appears to have stopped functioning.
Could I configure another pin ...
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1answer
36 views
gpiozero import resets pullup
In order to use a GPIO connected button as a power off switch I have set a pullup for pin 23 in a dtb overlay (following http://blog.gegg.us/2017/01/setting-up-a-gpio-button-keyboard-on-a-raspberry-pi/...
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2answers
91 views
Multiple RPi and multiple external 5V power sources. Connecting all GNDs = ok?
First off, I'm a noob when it comes to hardware/electronics. Barely started and not planning on getting too deep in it.
I have a bit complex setup that boils down to multiple RPis (around 13, with ...
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3answers
102 views
Command/control latching relay using gpio pin only
first off, I'm a noob when it comes to hardware/electronics. Barely started and not planning on getting too deep in it.
Now, what I am trying to do may not be possible, hence this question.
I have ...
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2answers
156 views
/dev/mem vs /dev/i2c-1
What are advantages and disadvantages in accessing I2C and other interfaces directly with /dev/mem (as in this code) instead of using /dev/i2c-1 (as in most examples like this)?
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1answer
51 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 ...
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2answers
40 views
Connecting RPi to a motion sensor
I'm new to working with RPi GPIOs, and I never studied electronics so bear with me on this newbie question.
I have an RPi 2 Model B, and I'm tasked with detecting a motion detector alarm going off.
...
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Which language is best for Raspberry Pi Apps for better GUI and Firebase
I want to develop Raspberry Pi app which requires lots of REST API calling, GPIO controls and very best GUI. I have done research on following.
Running C#.net or VB.NET apps in Raspbian OS using Mono....
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1answer
28 views
Wireless doorbell using gpiod
Good Morning,
I have a non issue that I am just curious how its working. So I have a wireless doorbell that I built. It works using the gpiod and remote gpio. So I have a chime unit that I built with ...
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0answers
27 views
GPIO LED is constantly on. GPIOZero can't turn it off
If power is supplied to the Pi then the LED will be on by default. I've got the LED connected to GPIO pins [4, 6] and the script can not turn it off. I've switch the cables around and that's resulted ...
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2answers
95 views
How to check if SPI is enabled and functional on Raspi 3b+?
I have run raspi-config and enabled SPI and also verified that /boot/config.txt contains the line:
dtparam=spi=on
However, when I run lsmod | grep spi I get the following:
spidev ...
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0answers
18 views
How to attach Air208 GSM micro sim card board to raspberry pi zero w that already has display attached on GPIO
I have a Air208 GSM micro sim card board that I want to attach to my raspberry pi zero w to make calls.
The issue is that I already have a 3.5" tft display attached to the pi zero w via GPIO (header ...
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1answer
40 views
Connecting jumpercable to gpio pins
My teacher gave me a large group of jumper cables attached to one another.
this might be a stupid question but if it's attached like on the on the bottom picture what is the order of the cables? (...
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1answer
28 views
gpio command from terminal
I have two simple scripts, one in Python, one in bash to turn on and off a LED.
I don't know what I'm doing wrong but if a run the bash script nothing happen, while the Python script It works flawless....
