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Heltec-Aaron-Lee / WiFi_Kit_series

Arduino source codes and toolchain for WiFi_Kit_series made by HelTecAutomation.
GNU Lesser General Public License v2.1
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Reading battery level on A4 during loop #90

Open troyroberson opened 5 years ago

troyroberson commented 5 years ago

I can read the battery just fine during the setup() routine, but it always returns zero after it is read ever minute during a loop. Am I missing something?

Here's the function I'm calling from loop()

void getBatteryLevel() { measuredvbat = analogRead(VBATPIN); //delay(1000); measuredvbat *= 2; // we divided by 2, so multiply back measuredvbat *= 3.3; // Multiply by 3.3V, our reference voltage measuredvbat /= 1024; // convert to voltage }

ChristianSasso commented 5 years ago

Are you using wifi? The battery voltage pin (13) is on ADC2 that has shared functions with wifi on ESP32. Since wifi has higher priority, the ADC2 doesn't work while wifi is active.

leifle commented 4 years ago

I have the same issue. Having loads of delays and multiple readings behind each other does not change a thing. I think Christian Sasso points in the right direction, that it can not be read while the Wifi is on.

It works perfect if I have no Wifi and the thing on USB. But then I really don't need it.

Is there any trick how one can get a reading of the battery voltage while Wifi is on. Or do I have to turn Wifi off, read the voltage and then turn it back on?

Thank you very much in advance...