Bluetooth low power on ESP32

Q&A Forum › Bluetooth low power on ESP32

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Michael Gerndt asked 3 years ago

The function in the notify example

BLEDevice::init(“myESP32”);

does not terminate. The board reboot due to a watchdog. Do I have to enable bluetooth before running the sketch?

5 Answers

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Sara Santos Staff answered 3 years ago

Hi.
Can you tell me what is the exact example that you are trying to follow?
Regards,
Sara

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Michael Gerndt answered 3 years ago

Sara, first let me say that I like the book. It is good to have such a well presented intro. With respect to Bluetooth, I am trying to rung the two codes in Unit 2 of Module 5. I tried two different ESP32 boards and reinstalled Arduino and the boards. My suspicion is that Bluetooth is not enabled on the board. May be something that I have to change in sdkconfig somewhere?
Michael

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Michael Gerndt answered 3 years ago

Thanks to a student I found out that switching from the ESP WROOM Dev board to ESP WROVER Dev board in the Arduino GUI makes a difference. With the latter the BLE sketch works. But why. The board is actually ESP-WROOM-32 based.

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Michael Gerndt answered 3 years ago

I found the problem. I changed the CPU clock frequency to 10 MHz (esp32.menu.CPUFreq.10=10MHz (40MHz XTAL)) on the WROOM board. This seems to switch off Wifi and bluetooth. Switching back to 240 MHz, bluetooth works. Any explanation?

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Sara Santos Staff answered 3 years ago

Hi Michael.
Thanks for sharing that valuable information.
I wasn’t aware of that. We never had to change any settings to make bluetooth work on our boards. So, I don’t know why it’s that the case for your board.
So, now you are able to run the examples properly, right?
Regards,
Sara