Habits of the Heart

building the monitor \|sensor circuit \| download program
Mindstorms™ Heart rate monitor
	Using a Mindstorms™ RCX Lego™, a chest-strap heart-rate-monitor and an adapted Lego™ light-sensor, you can build your own tool for datalogging and graphing. click thumbnail for larger image
	The RCX with a light sensor attached. click thumbnail for larger image
	Polar™ chest-strap heart monitor with sensor. click thumbnail for larger image
Modifying the light-sensor In this process we've adapted a light-sensor to use to power the heart-rate sensor. * Understand that you will be permanently modifying the light sensor, and that they are not inexpensive.* (but may be a cheaper alternative to manufactured adaptors)
	This is the bottom of the light sensor. You'll need to remove the brown plate.(it pries off with a bit of force) click thumbnail for larger image
	Here are your soldering points for the three leads (before the removal of the light sensor. Click here for detailed instructions. click thumbnail for larger image
	After soldering the three leads. click thumbnail for larger image
	Use different colored aligator-leads to attach to the circuit to test it. click thumbnail for larger image
	The Vernier receiver for the transmitter, with a serial connector. click thumbnail for larger image
	The three leads are then connected to the female serial adapter. click thumbnail for larger image
	Here is a diagram of the male serial pinouts. click thumbnail for larger image
The finished test circuit
	Using Robolab 2.0, the education version of the RCX software, you can graph the results of your data logging.Use this link to the Robolab project to download the program that will run the heart rate sensor. click thumbnail for larger image