This circuit uses a common OLED display to show the signal from a pulse sensor in real time using a Raspberry Pi Pico. Essentially, the microcontroller and screen are acting as a crude oscilloscope.
Simply load main.py, live_pulse.py, and ssd1306.py onto the pico, and wire it up like so:
| Pico | OLED |
|---|---|
| GND | GND |
| 3V3(OUT) | VCC |
| GP6 | SDA |
| GP7 | SCL |
| Pico | Pulse |
|---|---|
| GND | - |
| 3V3(OUT) | + |
| GP28 | S |
In addition, you will get a better signal if you put a 0.1 microfarad capacitor between GP28 and GND. Now the circuit should run whenever the microcontroller is powered.