ArduinoGeneral

Firebeetle ESP32 read battery voltage

userHead cl3m3ns 2019-11-02 20:26:33 7772 Views19 Replies
Did anyone have success with reading the battery voltage of the Firebeetle ESP32?

According to the schema, pin A0 (=GPIO36) should be connected to VBAT with a voltage divider (see https://github.com/Frances9/DFR0478/raw ... 0)-SCH.PDF).

I tried reading that value and it just always return 0. Reading other pins with the same code works, so the code is correct.
2021-03-18 09:17:32 Do you mean that the two resistors R20 and R21 are not the same size? I did not encounter this situation. userHeadPic 347945801
2021-03-18 09:17:32 Do you mean that the two resistors R20 and R21 are not the same size? I did not encounter this situation. userHeadPic 347945801
2021-03-16 19:40:44 So I did some measurements, and I have:
4.05V on the battery and on R10
3.43V on R11 and on A0 instead of 2.025V
My solders on R10 and R11 are ok
But it seems that R21 is around 2.6 Ohms (instead of 1 Ohms on the schematic), which seems to correspond to the voltage I get on A0. It is difficult to measure it with the C4 attached to it but it seems to tend towards this.
userHeadPic zubrick
2021-03-16 19:40:44 So I did some measurements, and I have:
4.05V on the battery and on R10
3.43V on R11 and on A0 instead of 2.025V
My solders on R10 and R11 are ok
But it seems that R21 is around 2.6 Ohms (instead of 1 Ohms on the schematic), which seems to correspond to the voltage I get on A0. It is difficult to measure it with the C4 attached to it but it seems to tend towards this.
userHeadPic zubrick
2021-03-16 16:00:42 You can use a voltmeter to measure the voltage of pin A0. The voltage of pin A0 should be half of the battery voltage. If the voltage meets this value after the measurement, you need to check whether your program is wrong. userHeadPic 347945801
2021-03-16 16:00:42 You can use a voltmeter to measure the voltage of pin A0. The voltage of pin A0 should be half of the battery voltage. If the voltage meets this value after the measurement, you need to check whether your program is wrong. userHeadPic 347945801
2021-03-16 03:03:15 Hello,

I shorted the two resistors as suggested, but when I read the voltage using analogRead I always get the same 4095 value with analogRead(A0) regardless of the battery charge.
Did I do something wrong?
userHeadPic zubrick
2021-03-16 03:03:15 Hello,

I shorted the two resistors as suggested, but when I read the voltage using analogRead I always get the same 4095 value with analogRead(A0) regardless of the battery charge.
Did I do something wrong?
userHeadPic zubrick
2020-09-12 23:19:33 The schematic for the board shows a 10 nf capacitor C66. However there is not capacitor C66 on the board layout that you provided. Where is C66 on the version 4.0 of the firebeetle board? userHeadPic jpspoonhower
2020-09-12 23:19:33 The schematic for the board shows a 10 nf capacitor C66. However there is not capacitor C66 on the board layout that you provided. Where is C66 on the version 4.0 of the firebeetle board? userHeadPic jpspoonhower
2019-11-05 03:06:05 1) Where can I find the contact points in V4.0? The board is not labeled.
2) What other function is A0 reused for?
userHeadPic cl3m3ns
2019-11-05 03:06:05 1) Where can I find the contact points in V4.0? The board is not labeled.
2) What other function is A0 reused for?
userHeadPic cl3m3ns
2019-11-02 20:26:33 Did anyone have success with reading the battery voltage of the Firebeetle ESP32?

According to the schema, pin A0 (=GPIO36) should be connected to VBAT with a voltage divider (see https://github.com/Frances9/DFR0478/raw ... 0)-SCH.PDF).

I tried reading that value and it just always return 0. Reading other pins with the same code works, so the code is correct.
userHeadPic cl3m3ns