Last time I did the Hot wire foam cutter but I missed the temperature control. So that's why I made a simple PWM control. The whole project was based on Arduino ATtiny85 Digispark. For this project I only needed three pins, so the ATtiny85 is fine. Also I carried the wires in the PVC pipes. This article can also see here:

Hot wire foam cutter - Arduino PWM

Hot wire foam cutter

Step 1: Components

Arduino Digispark ATtiny85
Plastic box for electronics
Some wires
IRF530
5 x resistors 1k ohm
2 x resistors 100 ohm
1 x potentiometer 10k ohm
2 x BC547
1 x LED 3v
1 x 7812
Hot wire foam cutter

Step 2: Schematic Diagram

Step 3: Fixing

After soldering the circuit, we can mount it to the PVC pipe.

Step 4: Wires

The next step is to place the wires inside the PVC pipe.

Step 5: Software for the Controller

The software itself is very simple.

#define LED_PIN 0
	#define PWM_PIN 1
	
	
	int val = 0;
	long t = 0;
	bool sw = LOW;
	
	//the setup routine runs once when you press reset:
	void setup() {                
	  pinMode(LED_PIN, OUTPUT); //LED on Model B
	  pinMode(PWM_PIN, OUTPUT);
	
	  analogWrite(PWM_PIN, 0);
	  delay(1000);
	}
	
	void loop(){
	  val = analogRead( A1 );
	  analogWrite(PWM_PIN, val/4 );
	  
	  if( millis() - t > 1000 ){
	    sw = !sw;
	    digitalWrite(LED_PIN, sw);
	    t = millis();
	  }
	
	}

Download source code: Hot_wire_foam_cutter.ino

Step 6: Programming ATtiny85 With Arduino IDE

Select board digispark (Default - 16.5mhz)
Select programmer micronucleus
Press upload and connect ATtiny85 Digispark to USB. You have 60 seconds to do it.
Wait until it's over