Customer:
Is it possible to shut down the device (including ESP) via a pin (can be active low or high) when connected to a battery? Previously the device powered off when the supply was unplugged, but now we’re using a battery as a buffer for the power supply and need the device to fully shut down, not go into deep sleep. We’ve designed a bolt-on power latching circuit, but I wanted to check if similar functionality is already included on the PCB.
Originally submitted via the contact form on soldered.com on 24 November 2023. Migrated to the forum for community visibility.
Soldered Support:
Adding a battery as a buffer for the power supply is a good idea. There is a KILL pin on the back of the device next to the power switch. When you send a positive impulse to it, the device will shut down, but you will need to manually reboot it. It should work with a battery as well.
Customer:
Does it have to be an impulse or is it triggered on the signal rise? And by manually reboot, do you mean press the power switch?
Soldered Support:
Just writing HIGH to the pin is enough to power it off - it doesn’t need to be an impulse. The power LED should shut off right away indicating that it’s powered off. Pressing the power button again turns the device on again.