DIY Automatic Soda Dispenser

Many projects here feature microcontrollers, but sometimes this is overkill, as “truebassB” shows in his automatic soda fountain. The build starts out simple enough, by constructing an enclosure out what appear to be scraps of MDF and other wood-like material. He then installs a pumping mechanism that pushes air into a sealed hole in the cap of a soda bottle. In turn, soda flows out through the other hole in this cap via a piece of food-grade PVC pipe.

To regulate how much liquid is pumped into a cup, a timing relay is used so that when a button is pushed, it will fill a cup for a certain amount of time. This time can adjusted with a potentiometer, and pumps roughly 150ml every 20 seconds.

Though perhaps not the most complicated electronics project you could take on, it introduces a few interesting concepts/components that would be great to keep in mind for future builds!