| ![Image](https://github.com/jbruce12000/kiln-controller/blob/master/public/assets/images/rpi.png) | [Raspberry Pi](https://www.adafruit.com/category/105) | Virtually any Raspberry Pi will work since only a few GPIO pins are being used. |
| ![Image](https://github.com/jbruce12000/kiln-controller/blob/master/public/assets/images/k-type-thermocouple.png) | [K-Type Thermocouple](https://www.auberins.com/index.php?main_page=product_info&cPath=20_3&products_id=39) | Invest in a heavy duty, ceramic, k-type thermocouple designed for kilns |
| ![Image](https://github.com/jbruce12000/kiln-controller/blob/master/public/assets/images/ssr.png) | Solid State Relay | zero crossing, make sure it can handle the max current of your kiln. You only need one SSR, even if the kiln is 220V. |
| ![Image](https://github.com/jbruce12000/kiln-controller/blob/master/public/assets/images/ks-1018.png) | Electric Kiln | There are many old electric kilns on the market that don't have digital controls. You can pick one up on the used market cheaply. This controller will work with 120V or 240V (pick a proper SSR). My kiln is a Skutt KS-1018 |
The pi has three gpio pins connected to the MAX31855 chip. D0 is configured as an input and CS and CLK are outputs. The signal that controls the solid state relay starts as a gpio output which drives a transistor acting as a switch in front of it. This transistor provides 5V and plenty of current to control the ssr. Since only four gpio pins are in use, any pi can be used for this project. See the [config](https://github.com/jbruce12000/kiln-controller/blob/master/config.py) file for gpio pin configuration.
If you're having trouble with hardware, I did too. Here is a [troubleshooting guide](https://github.com/jbruce12000/kiln-controller/blob/master/troubleshooting.md) I created for testing RPi gpio pins.