The HexCalc is a business card-sized calculator designed for microcontroller developers. It supports hexadecimal, decimal, and octal bases, making number representation easy to understand with binary visualizations and ASCII characters. The calculator performs standard arithmetic and specialized functions like bit math (AND, OR, NOR, XOR), modulus, bit shifts, and 1’s and 2’s complement. Users can set bit depth (8, 16, 32, or 64 bits) to simulate real-world programming environments. Additionally, it features a color mode to convert and visualize 16-bit and 24-bit color codes directly on its TFT screen, providing a useful tool for developers working with color data. Current Status: Cleaned up the code a bit and added comments. Also caught/fixed a few bugs and added a couple new features (auto-shutoff for the screen, ability to rotate color channels in 24-bit color mode using byte flip and word flip, etc.) Enjoy!