popper_roaster

A simple arduino sketch that allows automated or manual control over the temperature of a modified popcorn popper coffee roaster.

How it works

When in automatic mode, users can set a static time and temperature profile in seconds and the PID algorithm will attempt to adjust the voltage sent to the heating element based on a 0-100 scale.

Features

• You can dynamically change the proportional, integral, or derivative terms throughout the roast to help dial-in the heat output
• You can dynamically label different phases of the roast (dry-end, first crack, first crack end, second crack, etc...)
• Outputs to CSV format for easy input into spreadsheets and graphs

Output is formatted as: Time (sec), BT (bean temperature ºF), PID (values), HeaterPower (%), RoR (Rate of rise), Data Labels

Hardware used

• Nostalgia Air Popper
• Arduino Uno
• K-Type Thermocouple 1/8 inch diamter
• Max 6675 Module
• 40 DA Fokek Solid State Relay
• 16 awg wires

Acknowledgements

This sketch makes use of the following open source libraries

• Arduino PID Library
• Arduino Max 6675 Library