I particularly like this case study that I found over on edn.com for two reasons; 1) it is nice and detailed and explains the underlying science of a heart monitor that I'd never read before, and 2) I learnt a new word in the form of Photoplethysmography.
Actually there is third reason - it explains how an ARM Cortex-M0 processor, in the form of a Cypress PSOC 4 device, can provide the processing power needed for this complex case study, to quote from the article 'a single low-cost programmable system on chip such as the PSoC 4 from Cypress can replace the op-amps needed in this application as well as the MCU and LCD interface. Featuring the low-power ARM Cortex-M0 core, combined with programmable mixed-signal hardware, this chip provides a flexible and scalable low-power mixed-signal architecture capable of meeting the analog I/O, signal processing, and real-time computational requirements of this type of application.'
The article also details the algorithm used to calculate the calories burned depending on the heart rate by a typical treadmill or other device so, now I have a better idea of how the calories and heart beat details are calculated that are displayed on the treadmill when I go for a run, next step is to discover how my Nike+ Fuelband is working out my Fuel and Steps calculations.
I'm looking forward to trying to use the word Photoplethysmography in a conversation over dinner this evening. I'd better start figuring out how to say it first....