In this project, Arduino is used as a PID controller for the extruder heater and spool motor speed.
The extruder motor will not work until the extruder heat is at a desired speed. The heat is received with a thermistor. The heat will be controlled with PID.
There are 2 optical encoders, one on top and one on the bottom. If the plastic triggers the bottom encoder, the spool motor speed will be increased. If it triggers the top encoder, the motor speed will be decreased.
The left LED is for the encoders the right LED is for the thermistor.
The top and bottom encoders.