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ESP32 Sparkfun Reset with External Battery 3.7v

Posted: Mon Jul 30, 2018 1:00 am
by oegma2
I am using a ESP32 Wifi/Ble Board, Model: ARS01119B from https://www.elecrow.com/esp32-wifi-ble-board.html

I've written a program in Arduino to read the data from a DHT22 weather sensor and display it on a small SSD1306 screen and also upload my data to a MQTT Broker over wifi

This all works 100% if I use my USB-power cable <BUT> as soon as I unplug my usb-cable and use my Lipo 3.7v 2000mAh battery, the unit don't connect and looks like it reset's

As far as I can see on the data sheet for this product is that it geared for battery operations, and even charge your Lipo over USB

Any idea why my external battery can't get this unit to connect to wifi and just reset all the time?

Re: ESP32 Sparkfun Reset with External Battery 3.7v

Posted: Mon Jul 30, 2018 7:59 am
by f.h-f.s.
Could it be that the battery connector accepts 5v and drops it to 3.3v for the esp32?

Re: ESP32 Sparkfun Reset with External Battery 3.7v

Posted: Mon Jul 30, 2018 4:08 pm
by oegma2
Thanks for the feedback - I've looked at the datasheet and seems like the battery connector can take in from V3.3 volts up to a Max of 5V and will output max of 600 mA

And the unit works fine if i comment out the wifi part and run it on the battery. Doing that, it stay up and pulls weather data from the DHT22, updates the screen no issues...but add the wifi, and boom it reset all the time

Also looked the Battery spec up, and maybe wrong - seems like the battery is outputting max of 200 mA ..that maybe to little for the ESP32 wifi at full blast running at 19.5 dBm which pulls about 240 mA

Gone try tonight the following:
1. Make sure the Bluetooth is switch off
2. Reduce the RF single down to 14 dBm

If that fails will try:
1. Switch off wifi
2. Enable BLE

If that fails - get a battery with about 500 mA output and see if that helps

If anybody know how to make sure the Bluetooth is disable / or wifi please let me know - using Arduino IDE