designing sleep monitors prototype 2

Please check out the first part of my sleep monitors series first.
Back in May 2011, unsatisfied with the "software" solution I developed with the first prototype, I started developing a "hardware" based solution to develop a contactless sleep actigraph monitor.

And that's what I came up with:

Under the mess of wires, there is an arduino controlling:
.an annoying buzzer for the alarm
.a transceiver to synchronise time and the data collected to another arduino connected to the home router
.temperature/humidity sensor
.a Volatile Organic Compounds sensor (for ambient formaldehydes, diffusing from painted walls and furniture)
.a tilt sensor so I can just kick the table to stop the alarm. No snooze, it's for lightweights.
.a dark blue LED, when lights go off, it starts pulsating at 6 BPM for 10 min, this serves as an exercise to synchronise breathing with the slow pulsati
on, this helps relaxing and concentrating on the light pulse help the brain let go of any day worries, "mindful" trick ;)
The functionality is similar to the nightwave sleep assistant (£0.20 LED versus £40 night wave gizmo)
.at the front the PIR sensor, often found in alarm systems or automatic on/off lights, that's the "actigraph" sensing part checking for movements while the user
sleeps.

To this day it is still running. It has been upgraded with a dust sensor, a Geiger counter and a raspberry pi.

However I still needed a "baseline" to verify if the actigraph was accurate or not, so I developed a third prototype, the ultimate contactless sleep actigraph! You can read more about this in the next article "designing sleep monitors part 3"