[Wolf] had a Polar brand exercise watch that wirelessly monitored a chest strap that sends it heart rate data. It sounds like there’s some way to transfer data from the watch to a computer, but it’s only meant for use with Polar’s website. He wanted to do a little more with the equipment so he ditched the watch and built an Arduino-based heart rate monitor.
He’s still using the chest strap and was happy to find that SparkFun sells an OEM receiver for it. Just add a 32.768 kHz clock crystal and an optional antenna wire and you’re up and running. Once the receiver finds a transmitting chest strap, it will pulse an output pin with each beat of the heart. [Wolf] used the D2 pin of an Arduino Uno to connect to the receiver because this pin corresponds to one of the ATmega’s external interrupts. A rolling average of five inputs are used to help smooth the display data, which is shown on the 2.8″ LCD screen seen above.
ooh pretty
Reminds me of one of the visualizers in Windows Media Player!
Sparkfun page says the Polar Heart Rate Module – RMCM01, is out of stock and NOT available for backorder. There are comments from July 2011 asking about it but have not been answered
Oh wait… RobotShop shows a dev board with the RMCM01 in stock!
http://www.robotshop.com/sfe-polar-heart-rate-monitor-interface-4.html
5.5kHz. I really hadn’t been paying attention because I was unaware that off the shelf VLF equipment was being marketed to the to the DIY consumer. I read in another comment sparkfun may or will not be able to replenish it’s stock of the receiver, or stocking it isn’t a good return on investment. because of the low data rate capabilities of the VLF band,and that it’s not a very versatile receiver, there may be very little DIY interest in the module.
I actually got the RMCM01 module from ProtoPIC in the UK, they had three modules left (of which I purchased two)… Took about two weeks to get to my door, although only two days to get from the UK to my part of the world… Go figure! :P