We understand how to read the actual temperature and the components that the iron requires. I've created the schematic below using all of the components. The ATMega328p-AU microcontroller is shown coupled to many additional components. We have the MAX6675 thermocouple reader IC connected to the microcontroller via SPI. Additionally, there is a main input plug with a reverse voltage diode, a MOSFET to regulate the amount of power given to the heater, push buttons with pulldown resistors, a few pins for the UART port, and an OLED display for i2c communication. Additionally, we have a hall sensor, which was not utilized in this lesson. Finally, the heater output and thermocouple input are connected through four pins. The complete component list is available here:
