The Eagle schematic for ZonCoffee is included after the break. Note that this schematic still has a few quirks, but it should be accurate to the best of my knowledge. I will post the Eagle project once the design is finalized.
Prototype using a standard Arduino
- Piezo Buzzer (optional)
- Solid-State Relay- cheap on ($6, ebay)
- Rotary Encoder with Pushbotton (~$1.50, mouser)
- MAX6675- (free sample, maxim. This is an SO package, soldering will be tough)
- Thermocouple – ($3, ebay)
- Serial LCD – ($25, sparkfun)
- Screw Shield – ($14, sparkfun). Optional, but this will make your life much easier.
Permanent project without Arduino
- Arduino Permanent Install Project ($2, mouser)
- Mega328 with bootloader ($5.50, sparkfun)
- Rotary Encoder with Pushbotton (~$1.50, mouser)
- Solid-state relay – cheap on ebay ($6)
- Thermocouple – cheap on ebay ($3)
- MAX6675 – free sample (note that it is SOIC)
- You will need an Arduino or FTDI cable to program your ATMega328
- Additional components may be needed that are not listed here, such as screw terminals for wires, perf board, etc. Be creative.
I’m looking at ways to make this project cheaper, and I think I will add support for additional display types to the ZonCoffee sketch. A cheap 4-digit LED display could be used, and would be much cheaper than the $25 sparkfun display (although more of a hassle to wire, and less flexible with data displayed).
Drop a comment if you have any questions, recommendations, or if you know any sources for cheaper parts!