Hot Wire Foam Cutter - Arduino PWM

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.

See more: Hot wire foam cutter - Arduino PWM

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.

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.

Step 7: The End

Work finished time to test the hot wire. Soon it will be Easter, so I will cut out an Easter bunny.

Easter bunny from polystyrene.

See more: Hot wire foam cutter - Arduino PWM