what do you mean by serial-port-to-USB converter?

[aqlika05]

what do you mean by serial-port-to-USB converter?

because I didn't find the COM port in my device manager.
anyway for this case i'm used laptop

[chickenjohn]

Like this

[aqlika05]

hmm .. the application can read the data I sent from Arduino, but the waveform doesn't display anything. Is something wrong or like that?

this is the look that I got

and this log data is received by Android

here the data received by android is data made from Arduino ESP32, I can't use SendWave source code. This is the code I made in Arduino

[chickenjohn]

Hmm. Maybe try to send data with word size = 1 byte but not 2 bytes?
Also, what can you get if you press "derive value" in the menu after finishing receiving data?

[aqlika05]

Bro, I want to ask about data deviation that is displayed in the wave?
Do you know which settings are in the file?

This is the appearance of the application

[chickenjohn]

The ploting scaling is done at:

ECG_Monitor_on_Android/app/src/main/java/com/experiment/chickenjohn/materialdemo/DrawSurfaceView.java

Line 198 in 6abbac8

y = (int) ((portHeight / 2) - (((float) drawY) / 280.0 * (portHeight / 2)));

for portrait view and

ECG_Monitor_on_Android/app/src/main/java/com/experiment/chickenjohn/materialdemo/DrawSurfaceView.java

Line 201 in 6abbac8

y = (int) ((landHeight / 2) - (((float) drawY) / 260.0 * (landHeight / 2)));

for landscape view.

I don't remember why I scale the point like this but obviously it is not adaptable dynamically. You may write your own scaling mechanism according to your data range.