Automatic Marshmallow Roaster





Introduction: Automatic Marshmallow Roaster

This is a marshmallow roaster (duh). A stepper motor from an old printer spins the marshmallow, on a skewer, over the candle. The heat-shrink was used to attach the skewer to the motor's shaft, because the gear would not come off of the shaft. My AC adapter was 9 volts, but 5 or 6 would have been better. The wood frame is a 3.5" square screwed to a 3.5x8" piece of wood. Make sure to use a beeswax candle, because other candles will blacken the marshmallow. Don't forget to download the motor shield library from Ladyada's website.

Arduino source code:

#include <AFMotor.h>
AF_Stepper motor(48, 2);
void setup() {
motor.setSpeed(10); // 10 rpm
void loop() {
motor.step(480, FORWARD, DOUBLE);

P.S. Please comment and rate it!



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    10 Discussions

    hi i invented something like that with a soda can the other day ive been trying to post an instructable but i cant figure out how to post a picture......hhheeelllpppp

    Hey, my buzzer was a good one, it would go Buzzzzz!, when it gets 5V and it is LOUD! ... I recently got an Idea.... What if we placed the motor on a servo, and the candle would be replaced with nicrom wire, the wire would heat the marshmallow, and the servo would move the marshmallow away when it was finished. If anyone can do that it would be awesome!

    LOL! I did this a long time ago! I taped a skewer to motor and put the marchmallow on the skewer. The marchmallow caught on fire and I freaked out, so I put a 9V battery to the motor and chunks of melted marchmallow flew everywhere.

    1 reply

    It is a good project, if it works. While adjusting the speed I got hit in the face with a hot melted marshmallow. That was disgusting.

    Thanks again ... just so you know I wrote a program for the DC motors with a buzzer in the program. The program works, but I didn't test it on the real deal yet.... but the program tells the motor to be on for 2 min then off then the buzzer comes on for 15sec .... you get the idea. Plus you can modify it..... Here is the program...

    int ledPin = 13;
    int motoPin = 8;

    void setup()
    pinMode(ledPin, OUTPUT);
    pinMode(motoPin, OUTPUT);

    void loop()
    digitalWrite(motoPin, HIGH);
    digitalWrite(motoPin, LOW);
    digitalWrite(ledPin, HIGH);
    digitalWrite(ledPin, LOW);

    Now for the test I put the motor on pin 8 and the test LED ( or buzzer) on pin 13, but feel free to change it up.

    Thanks again.

    1 reply

    Your code looks good, but there's one thing: If you use a buzzer, make sure it is the type that makes a tone when, not just a single click when you apply power. If yours just makes a click, you have to modify your code. Look under file/examples/digital/melody in the Arduino IDE for more info. Or you could always use an LED. Good luck

    I tottaly wanna make this when my arduino gets here .... do you think i can do it without the motor shield? Thanks for the idea !

    1 reply

    Your welcome!
    You need the motor shield if you have a stepper motor, but that's all I had at the moment. Use a DC gear motor (from an old toy or something else) and skip the motor shield and the arduino, just connect it to a few AA batteries and a switch. Also, a servo could connect directly to the arduino, but you will have to modify it for full rotation. more info here:

    You will have to modify the code if you use a different type of motor.