Building a pulse oximeter with Arduino and an RGB Matrix Shield #COVID19

John Keefe writes about at-home pulse oximeters, those fingertip devices doctors use to measure the oxygen saturation in your blood, have been selling out everywhere thanks to the Covid-19 pandemic. SparkFun sells a DIY “pulse ox” sensor. It, like other pulse oximeters, shines light into the skin and makes measurements based on how that light is absorbed. John has built heartbeat-driven projects before and had been exploring new ways to monitor pulse rates.

The heart (ha!) of the project is the Pulse Oximeter and Heart Rate Sensor, which includes the sensor itself, a tiny brain to make the measurement calculations, and two “Qwiic” connections. Qwiic is Sparkfun’s system of making it easier to wire up sensors. So I also bought a little box of Qwiic wires.

I’d also need a microcontroller, a credit card-sized hobby computer, to run the show. Sparkfun makes its own version of an Arduino called a RedBoard that is Qwiic-friendly, and that’s probably the easiest option for anyone starting from scratch. I have several Arduino Unos lying around, so I got a cheap Qwiic adapter for Arduino, which the Arduino world calls a “shield.”

Finally, I got fancy and added an Adafruit RGB Neopixel shield — which is a fun grid of addressable LEDs — to make a display. This is wholly unnecessary; you can read values off the microcontroller with your own computer.

See the post for build information, GitHub for code, and the video below.


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