I am building the same using a PSoC( Programmable System on Chip). I will give a tiny snapshot from their site FYI. PSoC Mixed-Signal Array. I had corresponded with you some time back when you had guided me to making a temperature controller .It was a very nice experience doing the same.
A true system-on-a-chip, PSoC devices are configurable mixed-signal arrays that integrate the microcontroller and related peripheral circuits typically found in an embedded design.
mail from TF
Programmable System-on-Chip – PSoC – CY8C27x43
The PSoC family consists of many Mixed-Signal Array with On-Chip Controller devices. These devices are designed to replace multiple traditional MCU-based system components with one, low cost single-chip programmable device. PSoC devices include configurable blocks of analog and digital logic, as well as programmable interconnects.
They can also function as a standalone device without debugging capability. The EvalPod has a 28-pin DIP footprint on the bottom for easy connection to development kits or other hardware.