Best Way to Get VDD33 Measurement?

[Skedaddles]

Hello,

On the old esp8266 platform, we were able to make a simple call to system_get_vdd33() to get the current vdd voltage. This worked great as a way to get the battery status when powered directly from batteries. We're hoping to find a similar function for the ESP32-C3, but so far I haven't found one. The closest is the rom_phy_get_vdd33() routine, which some people report working if they use with bluetooth on but Wi-Fi off -- is there any official stance on whether this would work?

Other than that, it seems like the solution is to build a voltage divider so that the maximum battery voltage would be down around 1.1v. Does that sound right? Should the 1.1V be fairly stable even if the Vdd is starting to dip down toward 3.0V?

Any tips or guidance for accomplishing a battery monitoring circuit would be much appreciated.

Thanks!
--Sid

[br10101]

Me too