“This project is my rebuild of the Brick a Bottle or Three by Palingenesis. It has been redesigned to use an updated microprocessor along with a custom PCB and 3D printed case.
Schematic
The updated circuit is designed around a ATtiny1614 microprocessor. This 14pin device has 16K Flash memory and 2K Static memory which is more than enough for this project.
Rather than using a processor IO pin for each switch, the updated circuit wires the switches onto a voltage divider. Each switch generates a different voltage which is read via a single analog pin.
While the circuit can easily run on a single 3V battery, I decided to add a 3.3V regulator and power it using a power brick.
3D printing
The STL files are included. Either take these to a 3D print shop or if you have your own printer, run them through your slicing software. I used a 0.2 mm layer height and no supports for the top, back and LCD supports.
The button tops were printed with a 0.1 mm layer height. Change the filament to a contrasting color at the start of layer 69.
The PCB
As the ATtiny1614 microprocessor only comes as a Surface Mount Device (SMD), I decided to use SMD packages for most of the components in the build.”