heltec wifi kit 32 battery level ADC read

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Hi,

I am using heltec wifi kit 32 for my project. I was wondering if I could do any ADC read for the current battery voltage value?
Thanks

Question Tags: heltec wifi kit 32 battery ADC

6 Answers

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Sara Santos Staff answered 6 years ago

Hi.
Yes, you can do that. You just need to use an ADC pin.
Regards,
Sara

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Jayakumar Raghavan answered 6 years ago

Wondering which ADC pin to use in Heltec Wifi Kit 35 board.

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Sara Santos Staff answered 6 years ago

Do you mean Heltec Wifi Kit 32?
Is this the board that you have?

If this is the board that you have, you can follow this pinout to decide which pins to use. It is better to use pins that are not shared with the oled or the Lora module. For example: GPIO12 or GPIO 13.

I hope this helps.

Regards,
Sara

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Jayakumar Raghavan answered 6 years ago

Hi Sara,
I am using this wifi-kit. I am not able to identify the gpio that’s connected in-built battery to read voltage values from it.
http://www.heltec.cn/project/wifi-kit-32/?lang=en

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Sara Santos Staff answered 6 years ago

Hi.
Accordingly to this discussion:https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/issues/10
It seems to be GPIO32.
Regards,
Sara

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Sara Santos Staff answered 6 years ago

I found other article: https://hackaday.io/project/27791-esp32-lora-oled-module/log/69600-battery-voltage-measurement
And it mentions that the values read from the pin don’t make sense.
Probably, you’ll need to add a voltage divider to read the input directly from the battery.