[Meseta] built a powerful boost charger to top off his portable devices. He was inspired by the Minty Boost but wanted to overcome the rather limited capacity provided by the two-celled product. He ended up building his own DC to DC boost circuit rather than using an all-in-one IC. As you can see, the result uses four 18650 lithium-ion cells, normally found in laptop batteries, and can power two USB devices at the same time.
This pulse oximeter turned out very nicely. It is based around a Freescale microcontroller and detects pulse as well as oxygen saturation in your blood. The sensor is made of two wood pieces and allows two wavelengths of light to be shined through your finger. A sensor picks up the light on the other side of your stubby digit and the readings are compared to calculate saturation. Check out the finished project after the break.
We saw an Arduino-based oximeter a few months ago. These kind biometric hacks are rare around here. If you’ve got a well documented project don’t forget to tell us about it.
Continue reading “DIY Pulse Oximeter”
[Muris] is pumping out the home lighting hacks. He developed this motion sensing module as an add-on to the IR switch we saw last week. There’s some kind of fuse box above his entry door and its white cover, which you see above, is where he mounted an IR distance sensor to detect movement and switch on the lights. The RC5 infrared protocol is used to transmit the necessary signal to turn the lights on, then when a set amount of time has passed it will turn them back off again.