ESP32 Forum

Posted: **Thu Sep 02, 2021 5:22 pm**

Hi everyone! I'm new to the ESP-IDF world and I would like to thank the developer team for the amazing work done!

I'm currently working on an embedded system that read EEG signals and streams the data using Bluetooth with an ESP32 to an Android device. For this application, since my knowledge about Bluetooth is limited, I would like to hear suggestions from experts on which to use of the following:

Type of Bluetooth (Classic, BLE)
Type of Bluetooth stack (Bluedroid, Nimble)
Type of Protocols (HID, RFCOMM, GATT)

I understand the choices merely depends on my requirements for the applications, so here they are:

Send small packets 16 bytes long each
Continuous data rate of 250 Hz
Bidirectional control (ESP32 sends data to Android, and Android can send commands back, e.g., start/stop)
Use of FreeRTOS for running multiple tasks

Thank you for your time in advance, any suggestion will be helpful!

Posted: **Wed Sep 22, 2021 10:45 am**

I am also looking for similar suggestion to start of my project, Thanks in advance

Posted: **Wed Sep 22, 2021 3:09 pm**

I dont want to suggest any comm protocol, but this is what i found with very quick search:

- Brain Activity Monitoring: Sullivan and all. [21] proposed a brain activity monitoring system using the non-invasive electroencephalogram EEG sensor that measures the neural electrical activity of the brain from the scalp surface. The developed EEG monitoring system assisted by deep learning mechanism provides information about neonatal brain health to help clinicians in neonatal EEG abnormalities diagnosing. The proposed system uses a low-cost -low-power EEG acquisition system including BLE interface for communication. Besides that, the authors developed an Android app visualizing single-channel EEG and the neonatal seizure presence. A deep convolutional neural network and an algorithm for EEG sonification used to perceive EEG morphology changes.

https://link.springer.com/chapter/10.10 ... -51517-1_4

I bet there is few devices that are using BLE and some using BT classic. Good option is to make research about BLE 5.x which is much faster than 4.2.

Posted: **Wed Sep 22, 2021 3:22 pm**

Our custom board based on ESP32-WROVER-E, it has Bluetooth v4.2

and it requires to transfer of large files more than 3 MB of sensor data files. Hoping BLE would be good and not time taking.
Still doing reaching to go with Bluetooth classic or BLE, Seeing dependencies from App(android/iOS) side.

Posted: **Thu Sep 23, 2021 8:06 am**

3MB file is a big file in meaning of BLE usage. It takes few minutes to transfer it. In that case BT classic would be better option.

Posted: **Mon Sep 27, 2021 1:07 pm**

Any reference link to start with bluedroid to use both BLE and SPP (for large packets) in dual mode.

ESP32 Forum

ESP32 BLE suggestions for streaming EEG sensor data to Android

ESP32 BLE suggestions for streaming EEG sensor data to Android

Re: ESP32 BLE suggestions for streaming EEG sensor data to Android

Re: ESP32 BLE suggestions for streaming EEG sensor data to Android

Re: ESP32 BLE suggestions for streaming EEG sensor data to Android

Re: ESP32 BLE suggestions for streaming EEG sensor data to Android

Re: ESP32 BLE suggestions for streaming EEG sensor data to Android