Introduction

I had a commercial M&M's Dispenser like the one shown following and I thought: Is it possible to attach two mini motors and some electronics and automate it? Spoiler alert: Yes, it is possible!

Let's go for it!

The brand new M&M's Dispenser

The M&M's Dispenser setup

First, I had to open the M&M's dispenser to install the first motor and a lever mechanism to transform the rotation movement of the motor into a push and pull motion to open and close the M&M's gate.

The opened M&M's dispenser with the lever mechanism

To fix the motor to the M&M's dispenser I built a support using MDF. See the mechanism working in the video in the "The Automatic M&M's Dispenser in action" section below.

1/2 - The lever mechanism in detail

2/2 - The lever mechanism in detail

Base setup

I needed some kind of base to hold the M&M's dispenser and house the electronics. I found a small yellow wooden box (yes, it's Minios themed), perfect to match to the M&M's dispenser. I drilled some holes in the box to the second motor and the proximity sensor.

The Base wooden box (outside)

And put all the other components inside.

The Base wooden box (inside)

The final result was really nice.

The Automatic M&M's Dispenser ready to be used

Arduino

Hardware

The main electronics used are the following:

• 1 x Arduino Uno board: used to control all other electronics. I used an Arduino UNO board because I had one available, but it's possible to use some other cheaper alternative, like the Arduino Nano, for example.
• 2 x servo motors: one used to move the body of the figure, and the other to move the M&M's gate lever.
• 1 x proximity sensor: used to detect the presence of the hand in front of the dispenser.
• 1 x NFC shield: used to authorize the M&M's consumption.
• 1 x RGB LEDs: used to receive visual feedback from the dispenser.
• 1 x speaker: used to receive audio feedback from the dispenser.
• Some resistors.

Software

I used the Arduino IDE to develop the Arduino code (see the details in the "Versions" section following).

Versions

1.0.0

The first version had everything I had planned... the two motors, the led, the speaker, the proximity sensor, and the NFC circuit responsible to authorize the M&M's consumption. See it working in all its glory in the video in the "The Automatic M&M's Dispenser in action" section.

1.1.1

Despite the total success of the first version, I decided to rip off the NFC circuit to facilitate access to the M&M's, since the automatic dispenser was placed at home, and the "authorization" feature was not really necessary.

The Automatic M&M's Dispenser in action

The Automatic M&M's Dispenser in action (Lever Detail)

The Automatic M&M's Dispenser in action

Final considerations

This was really a "delicious" project to work on in all aspects :-) and the final result was such a success.

Have fun...