[Donald Bell’s] robotic bartender entry into the 2020 Cocktail Robotics Grand Challenge is one of those things that sounds easy until you start getting into the details. After all, how hard is it to dispense some liquids into a glass? Harder than you might think. Sure there are pumps — [Donald] uses peristaltic pumps — but there’s also two Raspberry Pis, an ESP8622, and at least one more microcontroller lurking underneath. You can see a video about the device below.
Even if you don’t want a refreshing libation, you’ll probably like the VK-01’s Bladerunner cyberpunk styling. What we really enjoyed about the post was that it took you through the concept sketches, some of the design trades, and even a cardboard prototype.
There are some interesting thoughts about the psychology of a robot bartender, too. Apparently, people don’t find it satisfying to push a button and have a drink silently pour out like a hospital coffee machine.
There’s also an RFID card that [Donald] had ambitious plans for, but for now, it just detects that the user scanned a card. The software is something called Hello Drinkbot, so the custom software doesn’t have to do that part.
On the hardware side, there were a few clever tricks. For example, since the pumps only run forward — you never suck liquor back up from a glass — the machine gets double duty out of a motor driver meant to drive four motors bidirectionally.