Components
| QTY | Part Description | Price |
| 1 | 30A Current Sensor Module ACS712 | $2 |
| 1 | SMP60N06-14 SILICONIX N-CHANNEL | $1 |
| 1 | FT232RL 3.3V 5.5V FTDI USB to TTL Serial Adapter Module | $5 |
| 1 | Atmega328P Pro Mini Board | $5 |
| 2 | TMP36 TMP36GT9Z Low Voltage Temperature Sensor | $2 |
| 1 | 6mm x 30mm F10AL250V FUSES 10A 250V | $1 |
| 1 | AGC In Line Fuse Holder Screw Type fit 6x30mm | $1 |
| 1 | MAX7219 8-Digit 7 Segment Red Digital LED Display | $6 |
| 3 | Old salvaged CPU heat sinks | Free |
3D Printed Parts
| QTY | Image | Part Description | Download |
| 1 |  |
Part for mounting CPU heat sinks to make contact with cup. | cupConnectorRev12.stl.zip |
Outcome
This project was doomed from the start but it was a good opportunity to experiment with Peltier plates, switching power with a FET, current sensors, temperature sensors, etc. The major flaws are listed below:
- A very small contact zone between the cup and the cold side of the Peltier which makes for poor conduction.
- Trying to cool a pint of water by cooling a small section of a metal cup. Since the water is not circulating and the contact patch is small, only water that is local to the patch would be cooled.
- Terrible efficiency of Peltier. For similar input power a conventional refrigerator work be much more effective. To maintain efficiency the warm side must be cooled.
Source Code
cup_cooler_code.zip
Note that the source code in the zip file above relies on the LedControl library.