“I’d been missing my meals in the local chain pub with their self-service drinks machines,” Spencer says of his motivation for the project. “I wanted to make a machine that could sit on my desk and pour drinks while I was working.”
At first, Spencer intended to create an automated home watering system. “Then, like many projects, things took a sudden twist,” he laughs. His first big decision was whether to make use of a standard Raspberry Pi computer or Raspberry Pi Pico.
“Both would have worked well, taking inputs, displaying a message on the OLED display, and activating the relays,” he explains. “In the end I went for a non-Pico Raspberry Pi computer as I liked the opportunity to SSH into it and select myself a drink from a different room (as long as the glass was under it).”
A glass act
The drinks machine incorporates a Touch pHAT, offering six touch-sensitive buttons. It also has an OLED display, a four-channel relay board, and two submersible water pumps. Spencer designed the case using Autodesk’s Fusion 360 CAD software. “I printed it in a lovely red filament, opting for a modular approach with each piece slotting into each other,” he says.
Although Spencer has created many projects (he can often be found at Raspberry Pi events up and down the country either speaking or helping out), for the drinks machine he insisted on paying great attention to the quality of the final build.
“This was the first project where I planned in advance the route that cables would take to make sure they were all hidden,” he tells The MagPi. “This was also my first project where I used custom-made cable looms for 5 V, ground, and I2C with heat shrink to tidy them up. I didn’t want it to look homemade, and I wanted it to dispense drinks without flooding my desk, too.”
Going down well
Spencer has certainly succeeded in creating a robust, fab-looking project and he’s been enjoying lots of cold beverages of late without ever needing to leave his chair. So how does it all work? “The drinks machine can either be operated by pressing the capacitive touch buttons or programmed to dispense a drink at a certain time,” he says of his device’s automatic credentials.
“When one of the capacitive buttons is pressed, a relay is activated and this switches on a small submersible pump.” The drink is then dispensed into the glass, while the name of the drink is displayed. But there’s room for improvement.
“I still need to add fail-safes such as empty glass detection,” Spencer says, again looking to prevent liquid from spilling. “But this has been a fun build and I am looking forward to seeing what comes next with it.”