Olimex Support Forum

Microcontrollers => ESP32 => Topic started by: jamin on November 23, 2020, 07:17:59 am

Title: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: jamin on November 23, 2020, 07:17:59 am
Hey,

I need help trying to monitor my battery voltage levels on this board. In the pin out guide it suggests I can jumper the "SENS_BAT_E1" connection to get an analog voltage on gpi35. I don't see this jumper on the board, can someone point me to it?
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: LubOlimex on November 23, 2020, 11:57:03 am
What revision of the board do you have? The jumper you seek should be called "BAT_SENS_E1", but it was added in hardware revision D boards and newer. It is a small PTH jumper. It is located near the CHRG1 LED.

It seems to be opened by default, meaning battery sense is not enabled. To have the readings to pin GPI35 - first find the PTH jumper pads, then solder the two pads together to close it (or place 0R resistor between the pads).
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: jamin on November 24, 2020, 02:30:40 am
Thanks for the response! The board is a rev C. Is this still possible to do? There is no jumper by the charge light.
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: LubOlimex on November 24, 2020, 10:40:23 am
There is no battery measurement circuitry in revision C boards, you would have to implement own circuit. Maybe look at the schematics of revision D and revision E and try to implement something similar.
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: jamin on November 24, 2020, 07:34:24 pm
Ok thank you! I have one more question. When the battery is plugged in and I disconnect the POE power everything shuts off. Does this mean there is an issue with my board? Also do you have a link to the Rev C. schematic so I can review?
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: LubOlimex on November 25, 2020, 11:05:36 am
Schematics are available here:

https://github.com/OLIMEX/ESP32-POE/tree/master/HARDWARE

Are you sure everything shuts down or just the LEDs? The design is made so when you operate on battery the LEDs are left unpowered to conserve power. Use another method to determine if the board works on battery.
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: jamin on November 26, 2020, 11:57:35 pm
You are correct. I had a couple relays that shut down as well which was something I didn't foresee as I lost the 5 volt section. Thanks for all you help and quick replies!!!!
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: LubOlimex on November 27, 2020, 08:40:14 am
Oh yes, for relays on 3.7V battery you might need to think of step-up converter.
Title: Re: ESP32-POE-EA Baterry Monitor on Pin 35
Post by: mathewss on December 26, 2020, 09:47:07 pm
I have rev D boards but I am not able to find this jumper. Any chance you can send a picture highlighting it.

Best
 SM