Thermoelectric coolers (TEC) operate by the Peltier effect (which also goes by the more general name thermoelectric effect). The device has two sides, and when DC current flows through the device, it brings heat from one side to the other, so that one side gets cooler while the other gets hotter.
It is time for fun. If you accepted that using Android phone to control hardware is fun:) Android become very popular and if you into microcontrollers it is pity not to use that knowledge for making cool applications. If you experienced with microcontrollers it is useful to expend your knowledge with any object oriented language. That can be useful for future job opportunities. For Android you need to know Java programming and usage of Eclipse IDE for Java developers. Maybe sounds hard, but today there are a lot of free online courses about Android and plenty of examples and complete projects.
The Serial Peripheral Interface (SPI) module is a synchronous serial interface useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be Serial EEPROMs, shift registers, display drivers, A/D converters, etc.Block diagram of the SPI module is shown on picture. Depending on the variant, the dsPIC30F family offers one or two SPI modules on a single device. SPI1 and SPI2 are functionally identical. The SPI2 module is available in many of the higher pin count packages (64-pin and higher), while the SPI1 module is available on all devices.