Breadboard Hexadecimal Display
It always bothers be to connect a row of LEDs and current limiting resistors on a breadboard. Therefore, I came up with the idea of making a display module to display 8-bit buses on a breadboard. Also, sometimes it makes life a lot easier if the bus data is displayed in hexadecimal. In the end, I decided to make a 8-bit hexadecimal display that will fit on a breadboard.
This module is based on a Holtek HT66F3185 microcontroller. I've programmed two modes for this module, which is selectable by a solder jumper on the back of the module. The most significant bit of the inputs can be either on the left or on the right, depending on the mode selected.