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Xinyuan-LilyGO / LilyGO-T-A76XX

LilyGo A7670X A7608X SIM7670G series
MIT License
128 stars 57 forks source link

Problem with reading battery voltage #13

Closed MilkoKrastev closed 2 years ago

MilkoKrastev commented 2 years ago

Reading the battery voltage using ADC Channel 7/GPIO35 does not work as expected. The value read is always the same although the battery voltage level drops. The module is not powered via USB, it runs only on battery.

Could you please post ESP IDF sample code that demonstrates how the battery voltage should be retrieved? My code works fine with TTGO SIM7000G, but does not work with A7670E. Any idea what differences between TTGO SIM7000G and A7670E could be causing that? Does the level of GPIO 12 matter when using GPIO 35 for reading the battery voltage?

Thanks!

LilyGO commented 2 years ago

Hello. Refer to this sketch

MilkoKrastev commented 2 years ago

Hi, I uploaded the Arduino sketch to one of my boards, and it shows

0.28V

which is obviously wrong. Any idea what could be wrong? I have not changed the example code in any way.

LilyGO commented 2 years ago

The sketch has been optimized. Which version of the T-A7670 do you use? What is the silkscreen?

MilkoKrastev commented 2 years ago

I test with two boards getting the same result. One of the boards is version 1.0, the other one version 1.1.

MilkoKrastev commented 2 years ago

I tried the updated sketch for battery voltage, but it always prints 3.88V regardless of the actual voltage in the battery. I tried with two different batteries with different voltage levels none of which equals 3.88V.

Any other ideas what to try next?

LilyGO commented 2 years ago

TTGO SIM7000G Detects the battery voltage. The A7670 version does not currently have this feature. This feature will be added in future optimizations .