Re: Wireless Heart Rate Monitor

From: Dan Major (nospam_at_this.address)
Date: 02/17/05 

Date: Thu, 17 Feb 2005 10:31:44 GMT

dalai lamah <antonio12358@hotmail.com> wrote in
news:tte3bb92z7ff.16ura5qxxoeno.dlg@40tude.net:

>> I gave up on the Polar stuff
>> and made my own system using off-the-shelf RF modules at 413MHz.
>
> And the "real" heartbeat sensor? What did you use?
>
I used the Polar plastic chest strap, just because I was lazy, and it
worked. For the EKG amp I used a simple programmable-gain instrumentation
amp (free sample from Analog) which gated a 555. The 555 output was hooked
to the input to an RF module that was sold by Radio Shack at the time.
Several other mfgrs make similae (Lynx, Abacom). Unit was slightly larger
than Polar xmitr as it used two 9v batteries, but still very small.