Hello everyone,
I've bought my mistake a polar HRM H1 which doesn't support Bluetooth.
Unfortunately I can return this type of products on Amazon.
I was wondering if there is a way that I could still use this product a N9.
Thank you

Propbably not. Sorry.

Ok thank you for the answer.
I've seen that for iphone users you can there is an adaptor.
Any idea for the N9

Still, no. It needs to support ANT to use - even the iPhone adapter.

Wel actually I've got 2 belts like that (one I am using with my Suunto device and a spare one) so I also thought of hooking up the spare one to my N9.

What I thought of trying, is to gut the belt and a bluetooth headset and wire up the BT transceiver to the belt to get it transmitting over BT.
It's bit of a hacking experiment, but I have not got any time yet to do it.

I'm trying to have a refund form Amazing but it doesn't look too good.
Please keep me updated if you have time hacking the device.
A Bluetooth chip is so cheap I would happily try hacking it aswell.
Do you have any idea where to start ?

Unfortunately not yet.

What I thought of doing is to open up the belt button, see that hopefully it isn't cast in a resin block and hunt with oscilloscope until I find some signal that's corresponding to measured heart rate.
then I'd couple that to the mic line of the BT headset and see if I can get it working, depending on the type of signal in the HRM possibly needing some base oscillator there driven bwy it and using it like FM converter... All is speculation yet, It might well be impossible.

Also I am not sure if it's actially 2-way communication, or is the watch part just listening to HRM signal from the button.
If the latter, it might prove to be impossible.

Other approaches; intercept the signal when it is in operation, (with a spectrum analyzer for example...) debug it and build a converter to use with N9, using forex. the microphone input to get the decoded signal to the device.

Hey Juiceme,
Sorry for late reply but I'm very interested to hack this device as it is no use for me rigth now.
I have opened it with a simple knife and it probably killed the sealing but it is good enough to close it back.
Here are some pictures:




Careful with the back cylinder shape metal piece (magnet?), two wires are connecting it directly to the motherboard.





Unfortunately I don't have a oscilloscope to research some more
....

After some research on internet I found a pretty awesome project:
http://randomcontent.wolfnexus.net/R...e/arduino-hrm/

He is using a RMCM01 chip that reception and filters the signal (5Khz) and outputs a 1 ms pulse at 3V for every heartbeat detected.

Do you think we could simply connect this chip (RMCM01) to a bluetooth emitter and voila ?

Thanks, that really looks pretty neat, you were able to open it up without destroying it (or at least it looks like that!)
I assume that the cylinder-shaped longish black thing is propably a ferrite-core antenna for the transmitter.


As far as I understand the RMCM01 is a self-contained receiver, you would not need to wire anything into the HRM button itself, it receives the wireless signal from it and for output, well, BT could be one valid solution to get the signal to N9.

However, on the project page the author says that the module is no longer available. There are alternatives, for example on page http://www.fact4ward.com/blog/ic-if/rmcm01/ but it seems that those too are not easily obtainable.

Unless there is some solution like that easily obtainable, the alternative is to try to directly interface to the HRM button electronics.

Actually now as I looked into it, the Suunto model HRM's like what I have use different communication protocol called ANT. http://en.wikipedia.org/wiki/ANT_%28network%29

yes , I understood that RMCM01 is a self-contained receiver so this would allow us to leave the polar heart emitter close and have a second device converting 5Khz to bluetooth (even better in my opinion )

As you mentioned they are some alternatives but they are quite expensive (39.9E) which contradicts the project idea.

I will do some more research if there is any website still selling the RMCM01 chip because it is so cheap 4.5E.

Does it means you are no more interested of hacking the device because you are not sure of compatibility ?