I did the hot wire foam cutter previously 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
- 1 x potentiometer 10k ohm
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 PWM_PIN 1
int val = 0;
long t = 0;
bool sw = LOW;
void setup() {
pinMode(LED_PIN, OUTPUT);
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.
Read More: Hot Wire Foam Cutter – Arduino PWM