Hi there,

I'm trying to adjust the schematic of this raspberry pi switch pcb to be controlled by an arduino uno.



Here's the link to the original pcb, they've open sourced it: https://www.pi-supply.com/product/pi-supply-raspberry-pi-power-switch/

And here's my attempt so far. It includes NPN transistors (I used BC547 instead of the 2N2222 displayed here). The mechanical switches and the circuit work, only not if I try to control it via the Arduino. Today I tried to replace the transistor triggering the ON switch with a PNP transistor which does seem to trigger the relay, but only if the Raspberry Pi isn't connected. Can anyone tell me by looking at my schematic what I'm doing wrong?

Here are the label descriptions:
PI_PWR_ON = Arduino Uno pin 7
PI_PWR_OFF = Arduino Uno pin 6 (in the circuit this triggers the unload of the capacitor, giving the Pi 2 minutes to shut down)
PI_PWR_KILL = Arduino Uno pin 5



Many thanks,
Mick

 

Hi

What are the control voltage levels from arduino?

For example, PI_PWR_ON =5v or 0v?

 

so Pin 7 has a 1K resistor attached to it, if I power it from my 5V adapter it reads V4.43 on my multimeter at the basepoint of the Transistor.

I made a small typo in the original post btw
PI_PWR_ON == UNO_RPI_ON
PI_PWR_OFF == UNO_RPI_OFF
PI_PWR_KILL == UNO_RPI_KILL