diff --git a/reference/gpio.md b/reference/gpio.md new file mode 100644 index 0000000..dd530b0 --- /dev/null +++ b/reference/gpio.md @@ -0,0 +1,26 @@ +--- +layout: reference +title: GPIO pins +tags: +- gpio +--- + +## List of GPIO pins + +These GPIOs are accessible through their kernel interface in `/sys/class/gpio/gpioXXX`. +For more information on how to use that interface, see Linux documentation: +https://www.kernel.org/doc/Documentation/gpio/gpio.txt + +|Name|Kernel number|Direction|Polarity|Description| +|----|------|----|----|-----| +|VOL_UP|404|in|active low|volume up button| +|VOL_DOWN|402|in|active low|volume down button| +|HEAD_nRESET|385|out|active high|set to low to reset head board| +|LS_nRESET|392|out|active high|set to low to reset low speed board| +|CHEST_nRESET|394|out|active high|set to low to reset volume board| +|WIFI_nRESET|401|out|active high|set to low to reset wifi chip| +|AUDIO_nRESET|405|out|active high|set to low to reset audio chip| +|HEAD_GPIO_CPU|386|in/out|N/A|extra GPIO to the head board| +|LS_GPIO_CPU|391|in/out|N/A|extra GPIO to the low speed board| +|STAY_ON_CPU|388|out|active high|pull high when flashing the low speed board to maintain power| +