Selection of Micro-controller: This is a no-brainer. Since the contest was sponsored by guys at Texas Instruments and they shipped me a MSP430 development board ‘Launchpad’ free of cost, I am morally obliged to use and feature their products. Also, before they gave me this freebie, I already had 3 launchpad boards lying around begging to be used. With my limited experience with MSP430’s, I found them to be much powerful than PICs and Arduino. Though they may not feature fancy USB ports or CAN/LIN bus (as with PIC) or have a huge fan following (like Arduino), what MSP430 have are multitude of ADC ports and almost all ports have programmable interrupts. And yes not to forget the internal DCO.
Posted below is the schematic of the sensor front-end, if you have any query about the design please free to post a comment. If you see the schematic closely I have also provided two additional sensor ports labelled XTR and WTR. They are designed to hold a LM35 temperature sensor and are intended to be used for measuring External Ambient and Water Temperature.