Connecting the display worked fine after installing the SSD1306 and GFX library from Adafruit. Text was tested and a random number generator were used to see the output work.

The number on the display, represents the pulse counted by the PPG sensor. The random number is now replaced by the output from the pulse sensor.

This display will be used for the biofeedback training aspect of the system.

Updated ECG

New design is more compact. The large capacitor was replaced with another type of capacitor. Also the connection to each of the electrodes became more secure by using a 3.5mm Jack, instead of loose alligator clips for testing.

In order to improve portable factor, electrodes were placed closer to chest in order to avoid noise from wire movement and limbs. With these new placements, the ECG device can more easily be fit into a single wireless device.

When moving my arms, legs, and necks, there was minimum distortion. With heaving breathing, the baseline shifted, but the QRS complex was still identifiable. However, overall the noise increased as the electrodes are closer.


The smoothing filter was placed to improve the quality. Also with the Arduino, the baseline was raised, so that the entire wave could fit into view(entirely positive)


A much clearer QRS complex, but the breathing decreases the quality of the signal and disrupts the Arduino program to reliably read heart rate metrics.