Arduino-Controlled Bunn Coffeemaker Automatic Fill/Brew System

Share it with your friends Like

Instructable at:

Automatically fills the reservoir of a Bunn coffemaker and initiates a brewing cycle. Duplicates the function of a commercial automatic Bunn brewer in a consumer model at a fraction of the cost!

The Arduino allowsa 2 seconds to 5 minutes setting of the timer, controlled by two buttons inside the case. The timer setting is stored in non-volatile memory and retrieved on power-up or reset. The LED will blink out the current setting if either setting button is held down after setting. I also added a 10 minute lockout timer after a brew cycle, as well as a panic button to shut off the solenoid by resetting the Arduino.

I use it with a Bunn coffeemaker, which has a pre-heated water reservoir. Hitting the timer button fills the holding tank and starts a brew cycle automatically. The 10 minute lockout allows time for brewing to complete and the water to reheat before the next cycle.

The valve works very well, although the adapters cost three times what the valve did on Ebay! Lots of Teflon tape was needed to prevent leaking of the valve’s 1/4″ NPT threads.


Write a comment