ESP32 Bluetooth compatibility with Whatsup calls

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Joined Nov 14, 2020
We are currently utilizing the ESP32 Lyrat Min 1.2 for an audio application. Our primary objective is to establish a Bluetooth connection between the board and a mobile phone or ipad or computer(any device with Bluetooth module), then this device will initiate calls using applications like WhatsApp or cellular. In this setup, the microphone from the EVKIT is intended to transmit sound, while the speaker plays the received audio from the call.

Currently, we have observed successful functionality with Google Meet calls. However, we are encountering issues with cellular and WhatsApp calls. We are curious if there might be a compatibility issue related to how the Bluetooth module handles different types of calls.

Could you provide insights or suggestions on resolving this matter? We appreciate your assistance in addressing this compatibility concern.



Joined Jan 27, 2019
Bluetooth operates based on profiles which are sets of capabilities for the many things BT connections can possibly be used for.

The most basic is HSP (handset profile). This enables two way monaural audio and is pretty much restricted to basic phone call operations.

The HFP (handsfree profile) is a superset of HSP. It provides the two way monaural audio, but also call establishment and control capabilities (pickup/hangup, hold, call waiting, etc.)

The A2DP (advanced audio distribution profile) is designed to establish high quality, stereo audio connections usually for music but possibly for high quality streaming applications.

Your ESP32 LyraT Mini is a monaural only board. I suspect but can‘t be sure the services you are having trouble with are expecting to use A2DP for the audio. If you can figure out which profiles are needed for each, it might shed some light.


Joined Jan 27, 2019
Thanks for your respons. The ESP32 Lyrate minI can works with A2DP and HFP according to their data sheet.
That’s a little odd because it is monaural. But, I would look for whether negotiation is providing the profile needed for the services you can’t properly use. I think it might be part of the problem.