With a learning sensor from http://www.aniomagic.com/learning_sensors.php Aniomagic, I built a smart coaster that can monitor the temperature of my drink: green means it's just right, red means it's way too hot, and white means I'll need to heat it up again.
Video here: http://www.aniomagic.com/examples/example10/example10.mp4
(or here http://www.aniomagic.com/examples/example10/example10.wmv )
The wonderful thing about the learning sensor is that I don't have to hook it up to a computer to reprogram it. If I wanted to monitor (say) a cold drink, I can recalibrate it by tilting the coaster, which activates the tilt switch.
The coaster goes to sleep after 30 minutes, and wakes up when picked up. (next: a version powered by heat from the drink)
Disclaimer: We make and sell some of the materials on our website.
Step 1: Ingredients
- red surface mount LED (digikey part# 67-1695-1-ND)
- green surface mount LED (digikey part# 67-1357-2-ND)
- white surface mount LED (digikey part# 160-1737-1-ND)
- tilt switch (mouser part# 107-2006-EV)
- large battery (CR2032)
- plastic battery holder
You'll also need
- some acrylic (or something similar)
- a soldering iron
- wire-wrap wire
- a laser cutter (lucky us :-)