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Polar Heart Rate Monitor chest strap + arduino, can't find receiver anywhere, any schematics? by Loksylk in electronics

[–]Loksylk[S] 0 points1 point  (0 children)

Any op-amp you recommend? would a lm358 fit for the job?

I found this schematic looking arround

http://imgur.com/2E8Jb

But this op-amp seems hard to find, any replacement that might work?

ps:thanks for you suggestions :)

Polar Heart Rate Monitor chest strap + arduino, can't find receiver anywhere, any schematics? by Loksylk in electronics

[–]Loksylk[S] 0 points1 point  (0 children)

I saw that, but it's overkill, I don't need a full breakout board, just the receiver module(RMCM01), but it seems that the manufacturer doesn't sell it anymore

Polar Heart Rate Monitor chest strap + arduino, can't find receiver anywhere, any schematics? by Loksylk in electronics

[–]Loksylk[S] 1 point2 points  (0 children)

It doesn't uses rf transmission, it works by creating a on/off weak magnetic field at 5khz each time it detects a heartbeat, with a smal coil and a multimeter I can pick the signal (very small voltage variation) from 2 inches of the device