Arduino VGA Terminal

Use an Arduino Nano as a terminal for your homebrew computer

• VGA video output of 320x480 pixels at 60 Hz
• 25 lines of text with 40 text characters each, on an 8x8 pixel font

Adapted from https://github.com/slu4coder/ArduinoVGA

The terminal supports 6-bit color output (2 bits per RGB channel), for a total of 64 colors.

Guide of available colors:

Example: Calling SetColor(LIGHTLIME) will set the current line color to #aaff55, and calling SetColor(DDARKBLUE) will set the current line color to #000055.

How to compile:

For an Ardiuno Nano:

You could use the Arduino IDE, but in my case it caused extreme flickering and instablilty. Instead, I recommend:

• Set Arduino Nano FuseA from default 0xFF to 0xBF. See original video.
• Install gcc-avr using sudo apt install gcc-avr.
• Install the required libraries using sudo apt install avr-libc.
• Install avrdude.
  • If you are using native Linux, use sudo apt install avrdude.
  • If you are using Windows WSL2, it cannot access COM ports. Download WinAVR and call avrdude from CMD.
• Compile and send the program using the makefile (make send). If you are using native Linux, you will need to modify the makefile slightly (line 7).

For an ATmega328P:

I used the Minipro/XGecu TL866II Plus programmer with the provided Windows software (Xgpro v10.37). If your programmer is different, some steps may vary.

• Install gcc-avr using sudo apt install gcc-avr.
• Install the required libraries using sudo apt install avr-libc.
• Compile the program using the makefile (make compile).
• On the programmer software, press Select IC and choose ATMEGA328P @DIP28 [1].
• Load the hex file (VGA_Terminal.hex) [2]. Navigate to the Device Info [3] tab and select the fuse bits indicated below [4] (remember that checked bits are programmed as LOW).
• Insert the ATmega328P in the ZIF socket and press Program [5].

Required hardware:

• The ICs used in the original video series
• 2 x 74HC08
• 3 x 680 Ohm resistor
• 3 x 1 KOhm resistor

Connect the 6 color bits to pins A0-A5, as indicated in the schematic:

Demo:

Note: The current version of the terminal (main branch) has a different text. This image corresponds to the 6-bit-color branch.