Description The sensor works on the principle of reflection of light. There are two parts to this sensor. one is the light-emitting-diode and the other is an ambient light sensor. Firstly, the light emitted falls on the blood cells in the veins and reflects back some light. The ambient sensor detects the light and sends the data signal to the host after some amplification. The signal is the analog type which ranges between the values 0 and 1023. The sensor needs only one wire to share and communicate data with the host. This draws around 3mA at both 3.3V and 5V.
