This Machine Makes Pour-Over Coffee Without the Hassle
Pour-over coffee is great, but it is also a hassle to make each morning. That's why Kendigh built this pour-over coffee machine.
The plebs may never understand it, but coffee aficionados know it in their hearts: the best cup of coffee is the one that requires the most effort to make. Drip coffee from a machine was the bottom of the barrel for decades until Keurig came along. Conversely, coffee from a french press was considered to be very respectable for a long time. But the current hotness is pour-over coffee, because it takes a long time to make and therefore demonstrates dedication to the warm bean water. However, this machine can make pour-over coffee a little more convenient.
This machine automates most of the pour-over coffee brewing process and does it in a way that coffee snobs may actually accept. The user has to start the process by placing a mug on the tray, then a coffee dripper with filter on top of that. But the machine takes care of the rest: it grinds roasted beans directly into the dripper, then heats up water and pours that over. It monitors the weight of the cup so it knows when to stop pouring. After that, the user can just wait a few minutes for the brown gold to filter down into the mug and then enjoy!
Kendigh built the enclosure for the machine using laser-cut plywood. A Raspberry Pi Pico development board, running CircuitPython, controls everything. It monitors the weight of the mug using an HX711 load cell and water temperature with a DS18B20 waterproof temperature sensor. It controls three motors in total: one for the bean grinder and two for the peristaltic pumps that dispense water. The two pump motors work with standard drivers, while the grinder motor requires a high-current driver.
The hot water comes from a consumer electric kettle, which the Pico is able to control with a micro servo motor that pushes the power button on the kettle. A more reliable alternative would have been to leave the kettle switch on, then control the mains power going to the kettle with a relay module. But this seems to work just fine — though it may require tweaking the design to operate different kettle models.
Kendigh says they lost the SVG files for the enclosure and so they plan on redesigning them. If we could offer one suggestion, it would be to make the new enclosure out of a material that is easier to clean than plywood. Otherwise, this is an awesome machine that makes pour-over coffee a little bit more convenient in the mornings.