ESP32: Store and Send data via BLE frequently

Question

I'm developing a sensor based on the ESP32-DevKit board where I sense vibration from an accelerometer. The application/sensor goal is to store the accelerometer data for 20s and then send all the data through BLE.

I'm currently using the ESP32 ADC (12 bit) for a fast sampling rate (10-100KHz) to get an accurate signal. The next step is to store this signal, but it will take as size almost 2MB, so I don't know if I can store it in the ESP32 and send it later via BLE (packet by packet), therefore a lot of tasks will end up degrading the process time and Energy.

The main points are :

• Fast sampling rate / accurate signal.
• Sending data to phone with the lowest energy possible.
• using ESP32-S2 to Store 2MB data and resend it to Phone app.

Is there any possibility of doing what I want to?

Answer 1

When storing the signal, have you considered compressing the data? If the accelerometer readings are very similar to the previous reading, then just storing the difference might save a lot of space, especially if you use a variable length format.

I have a project where I save GPS data, but because it is comparatively slow moving boats, the difference between two coordinates (every second or so) will be very small, so no point storing the full coordinates.