How do I plot ECG (EKG) graphs from BLE devices please?

Good day all :slight_smile:

I am facing the following issues and would like to seek some kind help please.

I am trying to create an Android App using App Inventor 2 (AI2) that can plot ECG (Electrocardiogram) graphs from 2 BLE (Bluetooth Low Energy) devices concurrently:

This is how the ECG graph should look like (the data in the BLE devices are fixed):

When scrolled/zoomed in, it should look like this:

However, the Android App that I created using AI2 could only do this:

As such, I am facing the following problems:

  1. Many data points seem to be missing
  2. Can't zoom in/out of the graph
  3. No labels/values for the x-axis and y-axis

Is there anyone who is able to kindly help me with these aforementioned problems please?

This is the set of code blocks that I used:

This is the aia file for my app:
Connect2BLESignals_WithGraphs.aia (218.0 KB)

Appreciate all help and input! :slight_smile:

Warm regards,


I am a nurse and also perform ECGs. Are you making this for fun or do you want to use it in a professional setting?

Hi Peter,

That's nice! :slight_smile:

I'm creating this app as a part of my final year project (FYP).

Warm regards,

Are the 2 ble devices especially made for this purpose?

Hi Peter,

Yes, they are.

This is the ECG data inside the BLE devices (both devices contain the same data):
ecg data.txt (239 Bytes)

This is the info regarding them:
info.pdf (210.3 KB)

(continued from above)

This is the file saved into the BLE devices:

This is another file (not quite sure what it is for, but it is also in the folder given by my TA with the above 3 files, so I include it here too):

Warm regards,

Have you seen this FAQ?

Will the data be read on the phone in real time? Or do you rather want to load a txt file into the application? How long will your data sample be each time?

Welcome Avana.

Here is some information about using App Inventor to plot ECG (also called EKG) data.

ECG or EKG filtering of data Help on mathematics of filters

ECG buffering How to show value received from HC-06 as a graph?

ECG graphing How to show value received from HC-06 as a graph?

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