Just ordered some new parts to work on a wearable prototype to read and collect bio-metric data. These parts don't quite fit the form factor that I'm aiming for but they make it much easier to work towards a more optimal design.

• Microcontroller - Adafruit Feather M0 Bluefruit BLE
• Pulse Sensor - Pulse Sensor Amped

I choose the Adafruit Feather M0 Bluefruit BLE as my microcontroller because it has a number of elements included that simplify prototyping:

1. Arduino compatible microcontroller (lots of community support)
2. Integrated USB communication (easier debugging)
3. On board connection for LiPo power (including voltage regulator and charging)
4. On board Bluetooth BLE

I decided to change my pulse (photoplethysmography) sensor from the MAXREFDES177 Pulse/Ox sensor to the Pulse Sensor Amped - for 2 reasons:

1. Only interested in pulse data (to determine heart rate) - don't need the oxygen saturation data.
2. The Pulse Sensor Amped can directly output IBI (inter beat interval) data directly from a microcontroller (using open source software).

It is likely possible to get this data from the Maxim breakout but the learning curve is to steep for me now. Another plus is that the Pulse Sensor Amped uses green LED's which are likely to make data collection from the wrist easier.

Just a quick update and now I'm getting back to working on this.