Summary of TIRED OF POPCORN? ROAST COFFEE INSTEAD
Ben Eagan transformed a hot-air popcorn maker into a coffee roaster using an Arduino for precise heat control. The system integrates a thermocouple with a MAX31855 interface and a relay to manage the heating element. A separate power supply powers the fan independently, ensuring operational balance alongside the mounted electronics.
Parts used in the Coffee Roaster:
- Hot-air popcorn maker
- Arduino controller
- Thermocouple
- MAX31855 circuitry
- Relay (or solid state relay)
- Power supply for heater
- Extra power supply for fan
We’ve seen a lot of coffee roaster builds over the years. [Ben Eagan] started his with a hot-air popcorn maker. If you think it is as simple as putting beans in place of the popcorn, think again. You need to have good control of the heat, and that requires some temperature monitoring and a controller — in this case, an Arduino. [Ben’s] video below shows how it all goes together.
With the Arduino and the power supply strapped to the sides, it looks a bit like something out of a bad post-apocalypse movie. But it looks like it gets the job done.
In addition to the Arduino, a thermocouple measures the temperature and that takes a little circuitry in the form of a MAX31855. There’s also a relay to turn the heater on and off. There are other ways to control AC power, of course, and if a relay offends your sensibilities you can always opt for a solid state one.
The only other wrinkle was the addition of an extra power supply so the fan could operate without the heater. There might have been some other ways to manage that, but power supplies are cheap enough and at least the strapped on power supply counterbalances the strapped on Arduino on the other side of the popper.
We’ve seen popcorn poppers used like this before, of course. Thermocouples are a great way to measure high temperatures, but there are lots of other ways to measure that particular quantity.
Source: TIRED OF POPCORN? ROAST COFFEE INSTEAD
- Why is an Arduino necessary for this project?
An Arduino is required to provide good control of the heat through temperature monitoring. - How does the system measure high temperatures?
The setup uses a thermocouple combined with MAX31855 circuitry to measure the temperature. - What component turns the heater on and off?
A relay is used to switch the heater on and off. - Can a solid state relay be used instead of a mechanical one?
Yes, you can opt for a solid state relay if the standard relay offends your sensibilities. - Why was an extra power supply added to the build?
The extra power supply allows the fan to operate without the heater and counterbalances the Arduino on the other side. - Is this method of roasting coffee new?
No, popcorn poppers have been used for this purpose before.
