參考資訊： https://github.com/jimgraygit/Onion 步驟如下：
# echo 0 > /sys/devices/soc0/soc/1f003400.pwm/pwm/pwmchip0/pwm0/duty_cycle # echo 100 > /sys/devices/soc0/soc/1f003400.pwm/pwm/pwmchip0/pwm0/duty_cycle