Guru
Joined: 05/03/2018
Location: NetherlandsPosts: 4723
| Posted: 10:25am 22 Jan 2025 |
Mick,
Simple idea: whenusing a original picomite, the Vbus is checked though GPIO24. Vbus is your input voltage. Vsys is the voltage that runs the RP2040.
When you add a larger capacitor (supercap ?) to Vsys, the RP2040 keeps running for seconds to minutes (depending the size of the supercap) during which period you can sample Vbus, record the power fail, save the power fail (including date-time) in your filesystem... and then go down controlled.
Just one e-cap or supercap, and a few lines of code.
Volhout