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I'm trying to create a power switch for my Pi Zero W. I've read a million times that when you short the Run pin and the pin next to it, it will start up the Pi if it was halted before and power was not cut.

However, shorting these pins does nothing on my Pi. If I short GPIO pins 5 and 6, it starts the boot sequence. Shorting the Run pin on a running Pi results in reset. But I'd like to use the Run pin to wake the Pi. Do you have an idea why it doesn't work, when everybody says it should?

Martin Pecka
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1 Answers1

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The Run pin on most Pi is directly connected to the RESET pin on the SOC.

Grounding Run should reset the system regardless of what state it is in (similar to removing and re-applying power).

I haven't tried this on a Pi-Zero-W, but it works on B+, Pi2, Pi3.

If yours isn't working there may be something wrong with the connection.

The pins 5 and 6 is implemented in bootcode.bin See https://raspberrypi.stackexchange.com/a/19754/8697

Once upon a time it used to be possible to HALT the Pi and restart, but ALL the Poweroff and Halt options now seem to do the same thing, and are implemented in the same code. It may be possible to execute the HALT in software.

Milliways
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  • I tried shorting it with several pieces of wire, and also "shorting" it with a resistor (but it was more than 10 kOhm). I also tried it on two different Pi Zeros... – Martin Pecka Dec 08 '17 at 06:36
  • Frankly "shorting it with several pieces of wire" appals me. The board is probably coated with some protective coating. I have push buttons mounted on my Pi, but at the least I would solder a header in place. – Milliways Dec 08 '17 at 06:44
  • But the way of shorting works to reset a running Pi. Do you think there can be a difference in the "reset from halt" case? – Martin Pecka Dec 08 '17 at 06:45