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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Geared motors not moving under load when connected to Raspberry Pi using (L293D) motor driver
Even though the motors seen above are geared and strong enough to move the car against a decent load (because I have tried with the same battery, just without the L293D motor drivers and the ...
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12 views
PIR sensor always high with Raspberry Pi 3
I'm working on a project in which I have a generic 3-pin PIR sensor
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39 views
Why is the GPIO number system seemingly random?
Here is the layout for the standard Raspberry Pi GPIO header:
There are many different types of pins throughout the header in what appears to be a non-ordered fashion:
The 5V power pins are next to ...
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3answers
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Best way to gain access to more gpio pins on a raspberry pi 4
I am working on a project that requires the use of many gpio pins (ideally 100+). All those pins need to be able to do is turn on and off in a frequency of ~10hz. The only boards I was able to find ...
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1answer
24 views
Mirror imaging the Raspbian desktop for GPIO screens
How can I make the raspbian desktop look like I am viewing in front of a mirror? (basically backwards) I've already looked in the documentation for config.txt (here is a link) and tried to use rotate, ...
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Motion Activated Spotlight?
So I've successfully made a Motion Activated CAMERA that I've installed in my garage for various irrelevant reasons. The thing sends me an email when it detects motion, and sends me recordings of said ...
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Buttons connected to uart including standby/power button
I have a electronics project (32x32 Pixel led panel) with a raspberry pi as computing unit.
This device has a self made PCB with holds 2 voltage regulators, one for the onboard micro controller (atmel ...
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17 views
Connecting Pi to AVR with both I2C and ISP
So I'm attaching an ATTiny85 to a Pi Zero to build a variant of this WS2812 LED driver. The Pi talks to the ATTiny via an I²C/TWI interface.
However, I also want to be able to update the software on ...
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2answers
28 views
OpenOCD help please
I built an open source electronics project which requires me to program the board with jtag. I already had a raspberry pi 1 b+ so I decided to try and use it to do the programming. I cant seem to get ...
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Can't get to toggle leds with WiringPi library in C
So I got my python code to run that basically just toggles the LED, but now I tried enabling the GPIO via WiringPi library in C but it doesn't work. Considering python code runs, there isn't really ...
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1answer
26 views
Not getting a full 3.3V instead getting like 0.7V on a GPIO pin
Okay so I ran the following code and I am seeing ~0.70V on the GPIO pin and not 3.3V. Why could that be?
#import the GPIO and time package
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
...
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2answers
34 views
Using PWM with RPi.GPIO in Python
Scenario: I want to control a PC fan using the Raspberry Pi. The 4-wire-fan (MGT9212UR-W25) has its own power supply (12V) and can be controled via PWM. I would like to control it with a Python script ...
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1answer
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Raspberry Pi screensaver/DMPS on/off to trigger shell script on change
I've got a touch screen without backlight control and and turning off the HDMI-output just brings up a "no signal" placeholder on the screen.
I've soldered a octocoupler to the power toggle ...
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20 views
How to configure Pi zero as a RS485 slave device?
I want to configure the RPi zero as a slave device in the RS485 network. But I am not sure how to implement it in the software(C/C++).
The idea is RPi is doing some image processing, and whenever the ...
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39 views
Rpi 4 not booting after adding new i2c bus. changes made in config.txt
I made changes in config.txt to add a new i2c bus to connect a serial display as a temperature sensor is already connected to the default i2c bus.
I took the following steps:
Enabled i2c in Rpi ...
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1answer
50 views
problems lighting up LED on pi 3
HI i am new tp pi and python and wanted to create something that simply turns on and off a led.
It does not seem to work and not sure why?
here is the python script:
from gpiozero import LED, ...
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2answers
23 views
RPi.GPIO Cleanup() only specific pins?
Im using the Pi to control some relays, that in turn switch some light bulbs.
some code for clarification:
def do_work(job):
try:
duration = int(job.Duration)
gpioPort = int(job....
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1answer
19 views
Rasberry Pi 3 Pi4j does not work for digital pins other than RaspiPin.GPIO_07
I am trying to get a led working with the Raspberry Pin 3 model B+ with Raspbian. I am using Java Pi4j library this way:
GpioPinDigitalOutput digitalOutputPin = GpioFactory.getInstance()....
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1answer
32 views
Can Rpi GPIO pins be used to drive a DC motor? [closed]
I tried to GPIO pin to high and I cannot see output voltage. I try every solution but no one works for me.
import RPi.GPIO as g
g.setmode(g.BOARD)
g.setup(16, g.OUT)
g.output(16, g.HIGH)
I look GPIO ...
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2answers
46 views
Use GND as GPIO?
I've found a 5v relay board which is twice cheaper in comparaison with a board with 40 pin stacking header.
I can wire the Pi to the relay board using jumper cables but it look like messy.
My wish ...
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1answer
32 views
Reconfigure pi GPIO default states
The default states (right on boot), on my pi are:
+-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+
| BCM | wPi | Name | Mode | V | Physical | V | Mode | Name | wPi ...
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25 views
Raspberry Pi3 - Controlling 4 DC motors
I need to feed 4 DC motors of 5V on my Raspberry Pi 3 Model B using PWM (Pulse Width Modulation).
Currently, I have the next components: 2 NPM transistors, 1 L293D integrated circuit, resistors (220 ...
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1answer
45 views
433mhz transmitter fails using RPi Zero but works when using RPi 3
I've been successfully using a 433mhz transmitter with my RPi 3 to control some remote sockets with 433mhz receivers. I recently moved the project over to my RPi Zero and the transmitter has suddenly ...
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2answers
115 views
How to turn off relay when RPi shuts down
I have connected a relay to BCM 14 and by setting its output to HIGH I can turn it on, making a 220V bulb to turn on.
I use for that the following python instructions:
GPIO.setmode(GPIO.BCM)
GPIO....
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2answers
32 views
What GPIO pins are not multiplexed with essential components onboard
Hello I am in need a lot of chip select pins for my circuit (8 pins) and i am worried about pins being multiplexed which might suddenly pull high/low mid operation. Ill only be using the HDMI port,...
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34 views
Got a raspberry pi 3b+ 3v3 pin shorted. What can i do?
I've bought a Raspberry Pi 3 model b+, to try as a simple computer
Put it on the case, tried for some time, but it did not hit the performance i was expecting, so droped this idea.
I kept it save, ...
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1answer
57 views
RPi 4 — Garbage on serial console (UART) using upstream kernel
I'm experimenting with upstream kernel and now I try to get serial console working. I'm getting only garbage symbols when I try to communicate:
I think it is important to notice that I only get ...
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1answer
25 views
libpgiod vs wiringPI ports/pins etc
since sysfs is deprecated, and wiringPi can't really be used anymore, I started with libgpiod.
I found some examples I am trying to play with. But nothing yet. (I am trying to get an libpgiod version ...
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0answers
29 views
Enabling software i2c causes boot failure
I have a Raspberry Pi 4 model B, fresh installation of Raspberry Pi OS. I am trying to use software i2c to get around the clock stretch bug in the broadcom 2835 chip.
I edit /boot/config.txt to ...
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1answer
37 views
Is it safe to connect a 3.3v fan to gpio instead of power? [duplicate]
I have a Raspberry Pi 4B and a fan. According to the instructions paper of the fan, it should be connected to
a ground and a 3.3V power
, or a ground and a 5V power.
So I've used the former setup ...
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xpt2046 LCD touch sreen doesn't work with xserver
I had installed the touchscreen on the gpio of my pi 0w and did worked like a charm.
Then I decided to install Xserver, lightdm :
sudo apt install raspberrypi-ui-mods
After what the screen is grey ...
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2answers
45 views
Output resistors and GPIO
I am planning to control a IC ([CD74HCT299E][2]). I have currently GPIO-pins directly hooked up to the IC. My Question is, does the Raspberry pi have resistors before the GPIO-pin, or do I have to or ...
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26 views
How to disable output to serial (GPIO) during boot
I'm trying to drive a motor control over the Raspberry Pi's GPIO serial pins (GPIO 14 and 15)
I've disabled the serial console, however, during bootup of the Raspberry PI, it still sends data over ...
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What are the alt functions of GPIO FL0 FL1?
I am going through the raspberry pi compute module and deciding which gpio pins to use for status led and LAN_RUN for LAN9512.
Seems like GPIO 31 and 33 have the least important alternate functions.
...
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I2C (and SPI) - Byte-by-byte
I would like to read multiple bytes from an I2C device but only one byte at a time. For example, to read 10 bytes from an I2C real time clock I would issue a single read command (send device code ...
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1answer
40 views
How do I use a Raspberry Pi to install OpenWrt firmware on a BT HomeHub 5a or PlusNet Hub One router
I have a spare BT HomeHub 5a clone (actually a PlusNet Hub One router). I would like to install the OpenWRT firmware on it, in order to reliably use it as a wired wifi range extender without a DHCP ...
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1answer
25 views
What are the specifics regarding schmitt trigger inputs to the gpio?
There are some references to the existence of Schmitt trigger inputs on the Raspberry Pi. There seems to poor and conflicting information on this point. There is https://www.scribd.com/doc/101830961/...
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2answers
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How can Rpi3B+ GPIO input IR signals direct from Optoma HX180X projector's remote control CN1082?
I am trying to record the IR codes from my projectors remote. Nothing seems to be working and I need some help.
I want to be able to directly record the IR signals that my remote is putting out when ...
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1answer
26 views
What's the difference between SPI CE0 and CE1 and any other GPIO?
What's the purpose of specifying SPI CE0 and CE1 when you can just toggle regular GPIO?
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1answer
33 views
How can I expand the 5V pins?
I require 2 more 5v pins to be used - as I would like to avoid welding the 4 wires directly to the 5V pins, I wanted to know if it would be possible to expand those pins.
I would require a small ...
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0answers
34 views
Reading Mitutoyo digital micrometer with rasberry pi
Im trying to read the value from my Mitutoyo digital micrometer 543-390B Datasheet. The micrometer is using a smartbox to communicate with PC, the box is using P87C51SBPN microchip P87C51SBPN ...
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3answers
46 views
What can be done to plug extra V5 output?
I'm currently playing around with the RaspberryPi 4 and a couple of sensors, each of them using a 5V pin.
I was wondering if I could plug another 2 sensors - could I output 5V from any other GPIO pin?...
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Rpi ILI9341 2.8" 240 x 320 5110 SPI TFT LCD Screen Setup Problem
I ordered a cheap 2.8 inch ILI9341 screen from Amazon (https://www.amazon.co.uk/240x320-Screen-Serial-Module-ILI9341/dp/B07MXH92RL/ref=sr_1_12?dchild=1&keywords=spi+screen&qid=1589230039&...
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Relay is behaving differently from tutorial
Given:
Raspberry Pi3
Sunfounder 2 channel relay
plugged into 3.3v
plugged into ground
plugged into pin 18
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)
GPIO....
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0answers
30 views
GPIO Power off on shutdown with retropie
i asked this question before but i have added a diagram to explain it more clearly.
I am building a retropie arcade machine with a raspberry pi. I have added a shutdown / startup button to shutdown ...
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0answers
37 views
How to cut power to gpio pins on shutdown
I am working on a project where i am using a pi running retropie to make a homemade arcade machine. i have wired and coded a startup/shutdown button. i would like to set up the pi n such a way i can ...
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1answer
20 views
Raspberry Pi fan does not turn on using Python
I'm trying to make my case fan turn on using Python code. I have connected the fan to the GPIO 4 pin and the ground pin. The code I'm using is below:
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
...
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0answers
39 views
Using a GPIO pin as output and input
Good morning everyone,
i'm working in a project that involves having an state pin and button detection.
The escenario is the following:
when raspberry pi finish booting, a pin is pulled HIGH (this ...
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0answers
22 views
Using RPI to control analogue VIDEX intercom system
I'm getting to grips with Python and RPI with the view to replacing one of the VIDEX 3311 intercoms at my workspace with an RPI device to answer the buzzer, see who's at the door (using extant systems)...
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0answers
23 views
Raspberry pi 0 - openocd debugging “jtag scan chain interrogation failed: all zeroes” and “already exported” problem
I am trying to install openWRT on a router using my Raspberry Pi Zero. I am following the exact steps as explained in http://www.alfredklomp.com/technology/experia-v8/
However, for some reason I keep ...
