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... without an Arduino (if possible).

I am aware there are well-made solutions like the WittyPi, RTC-Arduino circuits, and some others with relay switches.

If a power bank is directly connected to the Pi (which has shutdown with sudo halt), all I need to do is break and reconnect the circuit and the Pi would boot up right? Is there a way to do this? Either at precise times with an RTC alarm or crude intervals with charging/discharging capacitors.

I'm guessing hacking the powerbank itself is more complex so maybe the USB wire instead? I am not quite familiar with electronics so any guidance will be of tremendous help.

(My aim is for the Pi to take a picture, shut down, boot 1-10 mins later, and take another picture, etc...)

EDIT A rough idea I had: Where AB can connect Powerbank and Pi or Reset pin and ground. I would probably control the on/off of AB with R and C values? But the circuit seems strange though as the capacitor doesn't have a route to discharge. enter image description here

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You COULD do this, but would't it be simpler just to pull the RESET pin low?

Depending on exactly how it is shutdown there may be other ways of restarting the Pi, but this is the simplest.

EDIT

If you are going to boot in a couple of minutes, I wouldn't bother! The Pi still draws current even when shutdown.

  • Oh thanks for reminding me about the RESET pin! But wouldn't the Pi draw less current in its 'shutdown' state since there are no processes or programs running? – E-Tan Jul 8 '18 at 18:38
  • @E-Tan The Pi will use more power running applications, but even when shutdown the VideoCore is running and peripherals are powered. I haven't measured but I have seen that the Pi still draws 100mA when not running. If you hold the RESET pin low it probably will be reduced. NOTE this is probably less than you would need to power the relay. (I would't use a relay to trigger RESET - just a transistor or logic circuit.) – Milliways Jul 9 '18 at 1:02

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