In order to build an algCalc device, you will need the following components:
- 2x16 LCD display with a HD44780-compatible chipset
- 5x4 matrix keypad (see below)
- Arduino Nano (or compatible) board
The g in algCalc stands for gaming which is why the keypad is intended to be a matrix of mechanical keyboard switches (like Cherry MX Blue, for example), although you can use any kind of switch you want. The keypad should look like this (R is rows and C is columns): The wiring page will help you connect the keypad correctly to the Arduino Nano.
The original project uses a 18650 Li-Ion cell with a TP4056 charger and a MT3608 step-up boost converter module, although you should choose the way of powering your algCalc yourself, depending on your needs.