Interactive mug coaster, thanks to analog temperature sensor LM35 and uC builded-in analog-digital converter, device can read temperature from standing on it glass. Device calculates temperature and smoothly light-up our drink with slowly changed RGB colours. When temperature is under 20*C then displayed colors are cold, and when temperature is above 28*C then colors are hot. When nothing stands on device (temperatures from 20*C to 28*C) then it automatically swich off. Fusebits are: 4,8Hz internal clock, not divided by 8. Supply voltage is stabilized by 1117 type stabilizer to 3.6V. The red LED requires lower voltage, and current on that line is limited software by PWM. Top of device filled with Translux epoxy resin. For rest see schematic or ask in comments.
DOWNLOAD – eagle 5.4.0 project files and PDF’s, schematic, BIN and HEX code, source code BAS.