PicoVGA01

PicoVGA

PicoVGA uses a Raspberry Pi Pico to drive a VGA/TV display. PicoVGA was designed by Miroslav Nemecek.

The RP2040 processor contains 264 KB of RAM. This is not much for higher resolution image output and therefore RAM needs to be very sparing. In technical practice and for retro games (the processor does not have the power for more advanced games), 8-bit graphics output in R3G3B2 format (i.e. red 3 bits, green 3 bits and blue 2 bits) is fully sufficient. Output in 16 or 24 bits is not meaningful in normal practice, as the Raspberry Pico does not have enough memory or power to provide such large amounts of data in areas other than short demos. Using the dithering technique, interesting display results can be achieved even with 8-bit output.

Features

• Raspberry Pi Pico
  • Automatic overclocking of processor
  • Library uses the 2nd core, main program uses 1st core
• VGA
  • 8-bit output in R:G:B 3:3:2 format (256 colors)
  • VGA progressive output up to 1280x960 resolution
  • Automatic configuration video mode timings
  • Composite sync
• Video formats
  • 1 base layer and 3 overlay layers with transparency
  • 30 frame buffer formats: graphics, tiles, text, special
  • Colour palettes
  • Screen split into segments of different formats
  • RLE compression
  • Transparency with selectable key colour
  • Hardware sprites
  • Output layers to different color bits (color planes)
• PWM mono audio output
• Joystick connector(s)

Connectors

J1/J3 Pico Breakout Headers

• 2 of 1x20 headers

Pico Pin Use

• 8 spare pins
• JOYPAD has more buttons than Atari Joystick (8 vs 5)

Pico Pin	Pico Signal	PicoMite		Pico Pin	Pico Signal	PicoMite	DB-9	JOYSTICK
1	GP0	BLU_LO		40	VBUS	USB_PWR
2	GP1	BLU_HI		39	VSYS	5V
3	GND	GND		38	GND	GND
4	GP2	GRN_LO		37	VEN3	VEN3
5	GP3	GRN_MID		36	V3OUT	+3.3V	J6-7	NOT USED
6	GP4	GRN_HI		35	ADCREF	ADCREF
7	GP5	RED_LO		34	GP28	SPARE
8	GND	GND		33	GND	GND
9	GP6	RED_MID		32	GP27	JOYPAD_UP
10	GP7	RED_HI		31	GP26	JOYPAD_UPPER_RIGHT	J6-5	PADDLEB
11	GP8	CSYNC		30	RUN	RUN
12	GP9	SPARE		29	GP22	JOYPAD_DOWN	J6-9	PADDLEA
13	GND	GND		28	GND	GND
14	GP10	SPARE		27	GP21	JOYPAD_CENTER_FIRE	J6-4	RIGHT
15	GP11	SPARE		26	GP20	JOYPAD_LEFT	J6-3	LEFT
16	GP12	SPARE		25	AUDIO	AUDIO_MONO
17	GP13	SPARE		24	GP18	JOYPAD_FIRE	J6-2	DOWN
18	GND	GND		23	GND	GND	J6-8	GND
19	GP14	SPARE		22	GP17	JOYPAD_RIGHT	J6-6	FIRE
20	GP15	SPARE		21	GP16	JOYPAD_UPPER_LEFT	J6-1	UP

J2 - Mono Audio

• 3.5mm stereo jack
• Use with external amplified speakers
• Mono signal on both speakers

J4 - 5V USB B

• Power the card in an enclosure
• 5V power
• Full-size USB B
• No USB signals

J5 - JOYPAD

• Optional 1x12 Header matches pinout of Land Boards JOYPAD card
  • 8 switches
    • Up, Down, Left, Right, Fire, Center Fire, Upper Left, Upper Right
• JOYPAD card can be built without pull-up resistors
• 1:1 cable between PicoVGA01 and JOYOAD cards
  • Can use 10 pin Dupont housings (don't need VCC connections)

// Init the JoyPad pins
// #define PB_UL 16		// Upper Left pushbutton
// #define PB_RT 17		// Right direction
// #define PB_FR 18		// Fire
// #define PB_LT 20		// Left direction
// #define PB_CF 21		// Center Fire
// #define PB_DN 22		// Down direction
// #define PB_UR 26		// Upper right
// #define PB_UP 27		// Up direction

J6 - Joystick (DB-9)

1. UP
2. DOWN
3. LEFT
4. RIGHT
5. +VCC
6. BUTTON I
7. BUTTON II
8. BUTTON COMMON
9. GND

// Init the Joystick pins
// #define PB_UL 16		// Upper Left pushbutton
// #define PB_RT 17		// Right direction
// #define PB_FR 18		// Fire
// #define PB_LT 20		// Left direction
// #define PB_CF 21		// Center Fire
// #define PB_DN 22		// Down direction
// #define PB_UR 26		// Upper right

Atari Joystick

• Amazon Joystick link

J7 - 3.3V

• 1x2 header
• Additional power pins for external use

PicoVGA01 Mechanicals

Prototype Build Hardware

• Uses cards
  • Raspberry Pi Pico Breakout Board
  • Raspberry Pi Pico
  • VGAX49
  • Audio Filter Card
  • JOYPAD Card

Raspberry Pi Pico Breakout Card

• Raspberry Pi Pico in Small Plastic Project Box - Breakout board

VGA Adapter Card

• VGAX49
  • Built as VGAX49 3:3:2 8-bit build

Audio Filter Card

• GRID49-Audio Filter
• Repurposed from PiPicoMite01 Prototype build

JoyPad

Prototype Build Wiring

Pico Pin	GPIO	Signal Name	Color	Dest	Pin
1	GP0	B3	BLU	VGAX49	13
2	GP1	B4	BLU	VGAX49	12
3	GND	GND	BRN	VGAX49	20
4	GP2	G3	GRN	VGAX49	8
5	GP3	G4	GRN	VGAX49	7
6	GP4	G5	GRN	VGAX49	6
7	GP5	R2	RED	VGAX49	3
9	GP6	R3	RED	VGAX49	2
10	GP7	R4	RED	VGAX49	1
11	GP8	CSYNC	GRY	VGAX49	17
21	GP16		BRN	JOYPAD	10
22	GP17		ORG	JOYPAD	9
23	GND	GND	GRN	AUD-FILT	2
24	GP18		YEL	JOYPAD	8
25	GP19	AUDIO	GRY	AUD-FILT	1 or 3
26	GP20		GRN	JOYPAD	7
27	GP21		BLU	JOYPAD	6
28	GND	GND	BLK	JOYPAD	11
29	GP22		VIO	JOYPAD	5
31	GP26		GRY	JOYPAD	4
32	GP27		WHT	JOYPAD	3

Software

The PicoVGA library is written in C/C++ and allows output from the Raspberry Pico to a VGA monitor or PAL/NTSC TV, with a focus on ease of use in technical and gaming applications. It provides 4 graphic overlay layers with transparency, nearly 30 frame buffer formats that can be freely combined with each other, making do with limited RAM memory size. The limitation of output to 8 bits also contributes to RAM saving.

• PicoVGA GitHub repository
• Our PicoVGA GitHub repository

PicoVGA examples

• ProgramNameJS = My Joystick version of the programs

Ants - card game
	keyboard control: 'J' left, 'L' right, space select, 'D' discard, 'H' help, 'Q' quit

AntsJS - card game
	JoyPad control: left, right, centerFire=select, upperLeft=discard, Fire=help move, upperRight=quit

Balloons - sprite demo, floating balloons

Draw - draw graphics demo

Earth - rotating Earth globe

Eggs - game of Eggs+Chickens+Hens, variant of the Reversi game
	keyboard control: 'L' right, 'I' up, 'J' left, 'K' down, 'H' help, 'Q' quit, 'P' 2 players, 'D' demo, space stone, Enter ok

EggsJS - game of Eggs+Chickens+Hens, variant of the Reversi game
	  JoyPad control: right, up, left, down, fire=help, upoerRight=quit, centerFire=stone, upperLeft=ok
	  keyboard control: 'P' 2 players, 'D' demo

Fifteen - game
	keyboard control: 'L' right, 'I' up, 'J' left, 'K' down, 'Q' new game

FifteenJS - game
	     JoyPad control: right, up, left, down, upperRight=new game

Flag - animation of flag fluttering in the wind

Ghost Racing - car racing game, racing with player's ghost copy, demonstration of 3D perspective projection
	keyboard control: 'I' gear up, 'K' gear down, 'J' turn left, 'L' turn right

Ghost RacingJS - car racing game, racing with player's ghost copy, demonstration of 3D perspective projection
	JoyPad control: up=gear up, down=gear down, left=turn left, right=turn right

Ginger House - picture fairy tale book
	keyboard control: 'J' previous page, 'L' next page

Ginger HouseJS - picture fairy tale book
	JoyPad control: left=previous page, right=next page

Hello - simple demonstration, print text "Hello world!" on the screen

Hypno - hypnotizing rotating pattern

Level Meter - demo of music volume level indication

Life - game, reproducing cells
	keyboard control: 'L' right, 'I' up, 'J' left, 'K' down, 'C' copy, 'V' paste, 'D' clear,
		space flip state, Enter run life, 0..9 select slot

LifeJS - game, reproducing cells
	JoyPad control: right=right, up=up, left=left, dowb=down, upperLeft=copy, Fire=paste, centerFire=flip state, 
		UpperRight=run life
	keyboard control: 'D' clear, 0..9 select slot

Lines - moving line patterns

Mandelbrot - fractal pattern generator
	keyboard control: 'E' up, 'S' left, 'D' right, 'X' down, 'Q' zoom in, 'A' zoom out,
	'L' low resolution 132x100, 'M' medium resolution 264x200, 'H' high resolution 528x400,
	'I' integer arithmetics, 'F' float arithmetics, 'B' double arithmetics,
	'O' decrease number of steps, 'P' increase number of steps, 'U' increase system clock,
	'T' decrease system clock, space redraw

MandelbrotJS - fractal pattern generator
	JoyPad control: Up, left, right, down, Fire zoom in, upper left zoom out,
	keyboard control: 'L' low resolution 132x100, 'M' medium resolution 264x200, 'H' high resolution 528x400,
	'I' integer arithmetics, 'F' float arithmetics, 'B' double arithmetics,
	'O' decrease number of steps, 'P' increase number of steps, 'U' increase system clock,
	'T' decrease system clock, space redraw

Matrix Rain - simulation of Matrix code rain

Maze - game, simple maze with maze generator
	keyboard control: 'J' left, 'I' up, 'L' right, 'K' down, 'H' help (show door)

MazeJS - game, simple maze with maze generator
	JoyPad control: left, up, right, down, upperRight=help (show door)

Monoscope - test of various graphic modes
	keyboard control: '0'..'9', 'A'..'U' select videomode

Oscilloscope - demo oscilloscope simulator

Pacman - game of popular Pac-man
	keyboard control: 'J' left, 'I' up, 'L' right, 'K' down, 'A' pause

PacmanJS - game of popular Pac-man
	JoyPad control: left, up, right, down, upper right pause

Pi - calculate Pi at 4800 digits

Pixels - random pixels

Raytrace - ray tracing 3D demonstration of mirror spheres

Sokoban - game with 3000 puzzles and with their solutions
	keyboard control: 'L' right, 'I' up, 'J' left, 'K' down, 'H' help (solution),
	'R' restart scene, 'Q' previous level, 'W' next level, 'P' info

SokobanJS - game with 3000 puzzles and with their solutions
	JoyPad control: right, up, left, down, upperLeft=previous level, fire=next level, uppperRight=restart scene, 
	keyboard 'H' help (solution), 'P' info

Spheres - draw random spheres

Spots - draw random dot spots

Tetris - game
	keyboard control: 'L' right, 'I' turn, 'J' left, 'K' drop, 'A' pause

TetrisJS - game
	JoyPad control: right, center fire turn, left, down = drop, upper right = pause

Train - puzzle game with 50 levels and with their solutions
	keyboard control: 'L' right, 'I' up, 'J' left, 'K' down, 'H' help (solution), Enter OK, Esc escape, BS backspace

TrainJS - puzzle game with 50 levels and with their solutions
	JoyPad control: right, up, left, down, centerFire=OK, upperLeft=escape, fire=backspace, upperRight=help (solution), 

Twister - deformable block covered with 4 textures

Water surface - simulation of a rippling water surface

Assembly Sheet

• PicoVGA01 Rev 1 Assembly Sheet