Overview
This is the third iteration of Bob's calculator schematic. It's a behemoth of a device, with 17 different modules and 27 wires.
The main components include:
- 3x 555 ICs for the logic module
- 2x 74HC595 for the LED display
- 1x 74HC4094 for the keypad interface
- 1x 16x2 LCD display