To keep hackers fueled and hacking, why not hack a coffee maker into a coffee brewing robot? [Carter Hurd] and [David Frank] did just that at The Ohio State’s Hack OHI/O 24 hour Hackathon. They even won the “Best Hardware Hack”. The video below shows it in action but the guys sent us some extra details on how it’s made.
To give it a voice they put Alexa on a Raspberry Pi. Using an audio splitter they have the voice go both to a speaker and to an Arduino. The Arduino then uses the amplitude of the audio signal’s positive values to determine how much to open the “mouth”, the coffee maker’s hinged cover. As is usually the case, there’s some lag, but the result is still quite good.
The brewing is also controlled by the Arduino. They plan to add voice control so that they can simply ask, “Alexa, make me coffee”, but for now they added a switch on the side to start the brewing. That switch tells the Arduino to work one servo to open the cover, another to insert a coffee filter, and two more to scoop up some coffee from a container and dump it into the filter.
They replaced the coffee maker’s on/off switch with a relay so that after the Arduino closes the cover again, it uses the relay to start the brewing. The result is surprisingly human-like. We especially like the graceful movement achieved by the two servos for scooping up and dumping the coffee. Full disclosure: they did admit that it would often either not scoop enough coffee or scoop enough but spill a bunch on the group.
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