Measuring Physiology with the Adafruit Feather Adalogger #Feather #Adafruit #NeoPixels @Instructables @Adafruit

Via Instructables: rabbitcreek writes about using an inexpensive microcontroller and a sensor to monitor breathing.

I needed a microcontroller-sensor that would do this. Published methods of sensing a breath have included a expanding force sensor around your midsection, a temp probe that works on exhaled air being warmer than inhaled stuff, and sip/blow switches available on quadriplegic control units and strange laser sensors that look at patients expanding girth while in MRI machines.

The easy method settled on was an analogue thin-film sensor for detecting relative pressure differences that occur with rising water levels in washing machines. With a little bit of data tinkering the very sensitive unit is able to detect the subtle uptick in pressure that accompanies exhalation in a monitored space.

This project is fairly simple in construction. It involves a Analog read with a microcontroller, a sensor, a lipo battery for power and a neopixel stick and SD card for output. The absolute size of the unit can be reduced further if you want to forgo the card output and downsize the battery.

1. Adafruit Feather 32u4 Adalogger–great board about $20
2. Adafruit NeoPixel Strip
3. Lipo Battery–I used the same size as the Featherboard which had plenty of power
4. SD Card
5. Power Button–generic
6. MP3V5004G Series 0 to 3.92 kPa (0 to 400 mm H2O) 0.6 to 3.0 V Output — Mouser Electronics about $17
7. 0.125 OD hose for gas engines
8. 1/8 ID vinyl hose

To make your sensor waterproof you must enclose it some container–I used a small plastic pill bottle.

See the construction, software, and results on Instructables.