Re: ESP32 flash verify fails after a while
Posted: Tue Dec 19, 2023 5:56 am
True, we'll check the supply and power the device externally for testing.
We've tested the power supply of the device, and found that the max. current of the used LDO isn't directly the problem.
The worst spike is when BLE is started, but even then the supply voltage only dips from 3.15V to 3.1V.
This is the case until the battery voltage drops below 3.3V, where the combination of high current (equals higher dropout voltage) and low input voltage causes the LDO to drop out at this moment.
Our solution is in this case simply modifying the battery-SOC curve, so that the battery voltage stays >3.3V.
Never revisions might get a pcb redesign.
Edit: Forgot to mention that forcing the ESP to 3.3V also means that it can be recovered and properly flashed again.
Thank you for your help, @ESP_Sprite!