HiLetgo board will run bluetooth code only when USB is connected

[apanagos]

I am using the ESP32 board from HiLetgo https://www.amazon.com/gp/product/B0718 ... UTF8&psc=1

I have been trying to isolate an issue with Bluetooth not booting correctly when I power from an external 5v, but it starts correctly when the USB is connected. When I disconnect the USB it continues to work correctly.

To test I wrote a simple c++ app (IDF) that just turns the GPIO02 LED on an off and then allows me to turn this on an off via BLE. If I disable the code for the Bluetooth it will boot correctly from the external 5v (5v 10A power supply) but when I enable bluetooth and power up again the LED still flashes but no Bluetooth. If I then connect the USB then Bluetooth starts.

I am sure it is probably related to the initial current surge when the bluetooth is enabled but I am perplexed on how to get it to work just using external power.

[apanagos]

Out of frustration I bought the Adafruit Huzzah32 and ran the same code just changing some of the pin numbers.

It worked as I expected using just external power. It powered up and I was able to access BLE and turn stuff on and off.

So it is something with the HiLetgo design.

I had simplified the code quite alot of rule out anything else happening. I have two tasks , 1 that flashes the internal LED and the other for setting up BLE. This tasks is delayed by 5sec before starting.

I see that the LED is flashing but the BLE task does not ever seem to run only when using external power only on the HiLetgo board.

[aaronb]

I had a similar issue with my MELIFE ESP32 board when I powered it from its VIN pin. The product page said it wanted 3.3v via VIN pin, which I provided with voltage regulator. Most features worked but Bluetooth didn't without USB also plugged in.

Using a multimeter when powered by USB, I measured a voltage slightly higher than 3.3v on the VIN pin. I fixed my issue by powering the board with 3.3v power directly via the 3.3v pin and ignoring the VIN pin.