Do you need to fill a number of water bottles? Does that number just so happen to be six? If so, then you might want to check out this automated machine by Easy HomeMade Projects.
The build uses a turntable-style arrangement, with a half-dozen empty bottles held in place for filling. To start the process, the bottle holder rotates to a home position indicated by a microswitch, and when in place, produces a note on its LCD screen to “Press Start.” When ready, the user pushes the single interface button, causing the assembly to beep with a small speaker, then fill the first bottle with a length of tubing and a submersible water pump. It stops when the fill time limit is reached, and rotates through and fills the other five bottles under the power of a stepper motor and timing belt.
The device is controlled by an Arduino Nano and an A4988 stepper driver attached together on a custom PCB. While a relatively straightforward project, it appears to get the job done nicely. You can see it in action below, along with the build process and a short explanation of the code. A parts list is available in the video description, and the circuit diagram, PCB files and code are listed as “available soon.”