Power on a Raspberry Pi with Arduino

Question

I am working on a project which involves to power on/off a Raspberry Pi with an Arduino. In fact the project contains several sensors like a motion sensor and the Arduino will be supplied with a 10kmA battery.

The motion sensor is connected on the Arduino device.

Once the sensor detects a movement, the Arduino will receive the instruction to deliver the 5V to the Raspberry Pi.

How can I supply the Raspberry Pi with the Arduino? GPIO? USB?

I have already seen solutions to power an Arduino with a Raspberry Pi, but never the opposite.

Answer 1

Powering on is easy: just use a small relay that you control with your Arduino, and which switches the 5v from the battery to the RPi.

Shutting down the Pi should be done in two steps:

• Setting a GPIO connection to the GPIO header of the Pi, that "sends" the signal to shut down. The RPi must receive this signal as an interrupt on the GPIO and can execute a shutdown-script
• The second step should be to wait until the RPi has completely shut down. Maybe you can observe that with the help of the RPi LEDs or something like that (otherwhise, an unclean solution would be to wait XX seconds). After you know that the Pi is shut down, you can open the 5V relay again.