As far as most people are concerned, Amazon Echo devices simply provide an easy and convenient way to play music or turn on lights via voice commands. But they are capable of doing so much more than that. In fact, by utilizing well-documented workarounds, you can trick your Amazon Echo into controlling just about anything after you give it a simple voice command. Harrison McIntyre took advantage of that fact to build a machine that will automatically launch M&M candies into his mouth when he asks Alexa for chocolate.
McIntyre's project is particularly impressive, because it doesn’t just shoot an M&M candy into the air and rely on the hungry user to run across the room to catch it. Instead, it actually looks for McIntyre's face and then calculates the direction, velocity, and angle at which to launch the candy so it gets close to his chomper. It can shoot up to ten candies at a time, and does so based on a voice command. All McIntyre has to do is say “Alexa, increase the volume of Chocolate by 4” and the machine will fire four M&M candies directly towards his face at roughly 23 miles per hour.
This machine’s 3D-printed launching mechanism works a lot like a tennis ball or baseball pitching machine. A spinning wheel sits at the bottom of the hopper of candies and flings the candy when a servo motor pushes the next piece into the wheel’s grip. A hall effect sensor is used to monitor the speed of the spinning wheel, so the velocity can be adjusted. The machine is controlled by a pair of Arduino boards connected to a Raspberry Pi. When the voice command is issued, a computer vision script running on the Raspberry Pi is used to look for a face. If it’s McIntyre's face, then it will use his facial features to calculate how far away he is. The speed of the wheel and angle are adjusted accordingly, and the M&M candies are released.