16 VGA Output for Arduino
16 : VGA Output for Arduino
- Author: Devin Atkin
- Description: The final goal of this project is to create an arduino VGA driver. Currently it’s nothing
- GitHub repository
- GDS submitted
- HDL project
- Extra docs
- Clock: 25175000 Hz
- External hardware: You’re going to need to hook up a VGA output to the chip alongside the clock, to control it you’ll need some form of microcontroller
How it works
The name is overly ambitious but that’s why I’ll submit it to future submisisons as I add more features. :)
This project uses the CLK input to generate a VGA output, this will default to a Random noise output, the output can be set to a background colour using the SPI interface. 32’b1000_0000_1111_1100_0000_0000_0000_0000 32-bit configuration word configuration[31:30] = 2’b11 - Set output mode 00 = Random Noise, 01 = Solid Configuration Set Colour, 10 = Coloured Text (Color set by config), 11 = Bouncing Ball configuration[29:24] = 6’b111111 - Background Colour for Solid Colour and Colour Text configuration[23] = (Forced to 0 given utilization issues character memory array data input) configuration[22] = (Forced to 0 given it increases utilization too high, this may be implemented if I choose to join TT05 in the future )character memory array write configuration[21] = Write for the character memory. (Has issues due to utilization, may be implemented if I join TT05 in the future) configuration[20:15] = Character memory being written to row memory address
How to test
The design has been simulated and tested with the eric eastwood simulator using the output generated by tb.v. The output will be tested using a Basys 3 board prior to the final sumbission time permitting. The design is currently set up to output a 640x480 60Hz VGA signal. The output is currently set to a random test pattern. The design will have a way to adjust background colour, and draw onto the display using a few basic SPI commands. (Not yet implemented) I’m testing my output using a VGA simulator tool online https://madlittlemods.github.io/vga-simulator/ and will be testing on a Basys 3 board prior to submission.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | SPI MOSI | VGA HSync | SPI MISO |
| 1 | SPI CLK | VGA VSync | none |
| 2 | SPI CS | VGA Red 0 | none |
| 3 | none | VGA Red 1 | none |
| 4 | btn_up | VGA Green 0 | none |
| 5 | btn_down | VGA Green 1 | none |
| 6 | none | VGA Blue 0 | none |
| 7 | none | VGA Blue 1 | none |