Setting Power Button and LED with Device Tree Overlays

• Power On: short pin 5 and GND

• Power Off:
  In /boot/config.txt

  ​​​​# use gpio to shutdown
  ​​​​dtoverlay=gpio-shutdown,gpio_pin=26,active_low=1,gpio_pull=up # shutdown button on gpio pin 26 (physical pin 37)
  

• Power LED:
  In /boot/config.txt

  ​​​​# use gpio to display PWR LED
  ​​​​enable_uart=1    # PWR LED on gpio pin 14 (physical pin 8)
  

• Act LED:
  In /boot/config.txt

  ​​​​dtoverlay=act-led,gpio=16    # ACT LED on gpio pin 14 (physical pin 8)
  ​​​​# dtoverlay=act-led,gpio=16,active_low=on    # inverse on/off
  

Reference

• Raspberry Pi Pinout