heart rate transmitter

Discussion in 'The Projects Forum' started by diablo39, Feb 18, 2013.

  1. diablo39

    Thread Starter New Member

    Sep 23, 2011
    hello new hear wanted to post question on something i have just thought about and looking for some feedback or direction, or whether am barking up wrong tree hope you can help.

    i have heart strap which goes around chest, and from what i gather a signal is transmitted from the chest strap at 5khz and picked up by receiver in watch, which processes the signal and displays it.

    so when using this set up if the watch is taken certain distance away from chest strap (transmitter) the watch (receiver) no longer is able to collect the signal.

    so my question is.

    is it possible to build circuit in between the transmitter and receiver, which will receive the signal and amplify it and re transmit the single so that it can be receved at the watch. I was thinking from current knowledge that , first step build receiver i.e coil with resonance of 5khz or tuned to 5khz, then check the signal is the same from transmitter, then amplify with op amp, then re transmit, or is this not possible

    thanks hope you can help or point me in right direction​
  2. wayneh


    Sep 9, 2010
    I think you're correct in principle, but the devil is in the details. End to end, this could be a pretty tough project. I think you have little chance of success without the right tools (eg. oscilloscope).

    But you can divide and conquer; see if you can receive the signal from the belt and separately try sending a signal to the watch.

    For the middle part - relaying the amplified signal from the belt - you'll just need to choose the right solution for the distance and bandwidth you need, power supply you have available, and so on. If it's really 5kHz and you don't need huge range, a small FM transmitter/receiver would work fine. Like a wireless microphone.