Questions tagged [gpio]
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63 questions
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x2 sudo commands cannot be executed in terminal
I am running a Ubuntu system on my Radxa Zero 3E (single board computer)
Using its GPIO I am driving a 5V LED via an NPN transisitor. Everything works.
For switching it on I use gpioset $(gpiofind ...
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1
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difference between "line-name" and "gpio-line-names" in the devicetree for gpio
I'm trying to understand why the devicetree property line-name (which can be used with gpio-hog) sets the label attribute where as gpio-line-names sets the name attribute for each gpio associated ...
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How to read GPIO interrupt timing at the application layer?
I use the a40i(arm) processor and read the gpio interrupt flag at the application layer. I read the gpio flag as a character device. The gpio interrupt is given externally and has a stable 4ms period. ...
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Bit banging PWM on Orange PI with Rockwell chip
I've read up on bit banging and I know how it works but I don't know how to implement it. I tried just using libraries written by other people in C or python but I'm using an orange pi 3B which uses a ...
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Arm linux interrupt binding failed
I am running the Linux 3.10 kernel on an ARM processor and writing a gpio driver. The system assigned interrupt number 182. I used the echo command to bind the core and wanted to bind the interrupt to ...
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Failed to use pinctrl/pinmux in port multiplexing
I am working on an embedded Linux system (kernel-5.10.24), and now I want to setup a UART port (with RXD/TXD/RTS/CTS) from 2 GPIO groups.
The DTS is setting as follows,
&pinctrl {
uart0_pin: ...
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263
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How to define GPIO pin as PPS source device
I'm using Linux in an embedded environment. I want to use a particular GPIO pin as a PPS source to be used with gpsd. I think the pin is configured correctly because I can see high/low transitions ...
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2
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How to read a pin state on a Raspberry Pi and select (either/or) between two entries in a cron file?
So I built an MLB scoreboard with a RPI 3. Right now the display can either show my favorite teams playing, OR all the teams playing and cycle through them as they are going on. I would like to add a ...
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Unable to access GPIOs on Intel Alder Lake CPU
I have a motherboard with an Alder Lake CPU on it (i9-12900E). I'm trying to access the GPIO pins on the motherboard using libgpiod.
After I boot linux, I have no /dev/gpiochipX entries. When I run ...
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2
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Docker with device [GPIO] access while running as a specified user that is not `root`
We have an internal test system for our multi-platform software library which runs, with its zoo of third-party tools, inside an [Ubuntu] Docker container.
To keep things simple, the host machine AND ...
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gpiomon from libgpiod library seem not to behave correctly
I am trying to monitor GPIO events using libgpiod on the armbian linux.
Accourding to pinout of my device (BananaPI Zero M2 /w H3 allwinner chip)
I have pin CON2-P18 hooked on impulse button so I can ...
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773
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Converting to an immutable gpio chip
I have spent the last 10 hours trying to boot asahi linux on my M1 Mac, and now I can finally run the boot command. However, when I run it, there is an error message that says [0.202844] gpio ...
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How to access gpio-keys from a shell script
In my embedded linux system, I defined some GPIOs as keys in the device tree so I can use them as keys in my application. This works fine so far.
Now I want to add an early startup script to respond ...
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x86: Drive a SSD1351 OLED Display
I've a bunch of SSD1351 OLED displays like this one:
Those are driven over a SPI Interface and I use them in the Raspberry Pi and other ARM SBCs like the NanoPi with the following libraries:
https://...
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How to find the relation between a USB/TTL (dev/ttyUSB_) and it's GPIO pins (/dev/gpiochip_)
I have a number of USB/TTL adapters, based on CP2102N, which have four GPIO lines.
I can open one of the serial devices by /dev/ttyUSB0, and the related GPIO lines are controlled by libgpiod: /dev/...