GPIOgeneral-purpose input/output (GPIO)
CH341A USB to I2C / GPIO adapter
As you can see most of the pins are available on SPI interface, but D4 and D6 is missing. D6 can be found as RTS at the bottom of module.
Download and install the I2C/GPIO Linux kernel driver (This is a GPIO driver with some basic I2C functionality)
rmmod ch341 insmod i2c-ch341-usb.ko
Accessing GPIO pins from Linux
This example will show how it works with liting a led with writing 1 and turning off with 0.
echo out > /sys/class/gpio/gpio0/direction echo 1 > /sys/class/gpio/gpio0/value
Each pin accessible separate Di = GPIOi at /sys/class/gpio.
Check all available settings at: https://github.com/gschorcht/i2c-ch341-usb