Board spontaneously resets if backlight dimmed

[mcmanigle]

I have a simple application (weather / clock) that just connects to WiFi, periodically updates weather information, and displays it.

Everything works fine and it runs for hours (stable, low RAM use) if I leave the display backlight at full brightness. However, if I dim the backlight using PWM on GPIO1, the board will spontaneously reset after a couple of minutes. Anywhere between 1 minute and 15 minutes before it resets, randomly.

rtc_get_reset_reason shows POWERON_RESET or RTCWDT_BROWN_OUT_RESET. Either one can show, but otherwise the reset pattern looks random as described above.

I looked at the datasheet for PT4103 backlight LED controller, which suggests low-frequency PWM on the backlight control pin, but even using 500Hz, the reset still happens.

Is this something you have experienced or could test?

[lewisxhe]

Try connecting a battery to provide backup power to the board.