IO

Definition

Main Module - Core-3588JD4

Main Module - Core-3588SJD4 AI

Main Module - Core-3576JD4

Use

For example, to operate IO1 on the Core-3588JD4 main module (GPIO 36), you need:

1. Export the GPIO, run as root user:

   echo 36 > /sys/class/gpio/export

2. Operate GPIO, set to read input or output specified value:

   cd /sys/class/gpio/gpio36
   # set input mode
   echo in > direction
   cat value
   
   # set output mode
   echo out > direction
   # output low level
   echo 0 > value
   # output high level
   echo 1 > value

There are a few things to note:

• If the GPIO has been applied by other drivers, it cannot be exported successfully, and subsequent read and write operations cannot be performed.
• Involving the multiplexing of IO functions, if the function of the pin is already GPIO, the above method can be used; otherwise, the pinctrl state must be specified in the device tree.