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products:sbc:edge2:applications:gpio:40pin-header

This is an old revision of the document!


Edge2 GPIO header

Universal GPIO 40 pins board header, used for communication between board and different external devices.

Reference table

Current GPIO numbers valid for vendor kernel only. Mainline linux kernel GPIO numbers will be different…

GPIO num Name Pin Pin Name GPIO num
GND (0V) 1 21 GND (0V)
SARADC_IN4 2 22 MCU_SWDIO
1.8V 3 23 MCU_SWCLK
112 SPI1_MOSI_M1 / GPIO3_C0 4 24 VCC_MCU
111 SPI1_MISO_M1 / GPIO3_B7 5 25
114 SPI1_CS_M1 / GPIO3_C2 6 26
113 SPI1_CLK_M1 / GPIO3_C1 7 27
I2C6_SCL_M0_3V3 8 28
I2C6_SDA_M0_3V 9 29
MCU_IR_IN 10 30
PWR_KEY_IN 11 31
SARADC_IN3 12 32
VCC_3V3_S3 13 33
DEBUG_TX_3V3 14 34
DEBUG_RX_3V3 15 35
GND (0V) 16 36
PWM3_IR_M3 17 37
GND (0V) 18 38
MCU_USART2_TX 19 39
MCU_USART2_RX 20 40

GPIO usage examples

Please make sure that the GPIOs you want to use are not configured as other functions, if they are, you can follow Device Tree Overlay to configure them as normal GPIOs.

When you get the GPIO number, you can follow the steps below to control it. Here we take GPIO number 465 as an example.

Export GPIO

$ echo 465 | sudo tee /sys/class/gpio/export

Set-up GPIO direction

We can configure direction as input or output.

$ echo out | sudo tee /sys/class/gpio/gpio465/direction # Set GPIO output
$ echo in  | sudo tee /sys/class/gpio/gpio465/direction # Set GPIO input

Set GPIO value

$ echo 1 | sudo tee /sys/class/gpio/gpio465/value # Set GPIO output high
$ echo 0 | sudo tee /sys/class/gpio/gpio465/value # Set GPIO output low

Get GPIO value

$ cat /sys/class/gpio/gpio465/value # Get GPIO input value

Unexport GPIO

$ echo 465 | sudo tee /sys/class/gpio/unexport

Troubleshooting

If you got the similar error below, it means that the PIN you try to export is used for another function, you need to edit Device Tree Overlay configuration file to set the PIN as normal GPIO.

khadas@Khadas:~$ echo 465 | sudo tee /sys/class/gpio/export 
tee: /sys/class/gpio/export: Invalid argument
2022/06/30 00:01 · nick
Last modified: 2022/10/18 03:37 by hyphop