The worst device According to our own little experience, the worst device is a Raspberry Pi with Ant+ stick. Although it was develped by Johannes Bader, former PhD student from ETH Swiss Federal Institute of Technology in Zurich: https://sop.tik.ee.ethz.ch/people/baderj/ and he wrote a blog «Track Your Heartrate on Raspberry Pi with Ant+»: https://bin.re/blog/track-your-heartrate-on-raspberry-pi-with-ant/ on June …