I am a total beginner of Arduino and 3D printer. Is there anyone would like to share the code or source to control these:
1, I've got a hotend kit which already has the thermocouple and heater. How to control the temperature?
2, Nema 17 bipolar stepper motor and Easydriver. How to get a reasonable speed to make it available to push the filament through the nozzle smoothly.
Thank you so much!
For heaters you would typically use a PID control loop and a PWM output to modulate power to the heater through a MOSFET. You will need hardware to read the temperature sensor. Often they use a thermistor rather than a thermocouple. For a thermocouple you need a specialized amplifier chip. For a thermistor you need an analog input and the right formulas (See: Steinhart-Hart Equation.
For a stepper motor you need a stepper motor driver and software like the Stepper library or AccelStepper library.
I just messed up the thermocouple and thermistor. That's a really good point! Since my hotend comes with an NTC 3950 Thermistor, I think I have to use PID control. Do you have any source to recommend? Thank you so much!
There is a PID library. Go into Library Manger (Sketch->Include Library->Manage Libraries...) and filter for "PID". I think "PID by Brett Beauregard" is the one you want.