Here's a new code, it has only one color, but handles 21x32 tiles on the screen. Each tile is a 7 byte icon stored in flash, so you can have a lot of icons in flash, not RAM. The problem now is that the code needs more optimizations and also if I try to change the memory data for the tiles in real-time, the video goes out of sync. I need to figure out why.
Edit: I also changed the connections, I'm using SPI for the video output now.
/*
For connections, use:
Pin 9 = HZync (PWM) = VGA Pin 13
Pin 8 = VSync = VGA Pin 14
Pin 11 = RGB Video (SPI) = VGA Pins 1, 2 & 3 (or use just one to get a single color)
Ground the following pins on the VGA connector: 6 and 10
VSync us
64 - Sync = 1024 cycles
1020 - Blank = 16320 cycles
15240 - Lines = 243840 cycles
350 - Blank = 5600 cycles
266784 = cycles total (60 times per second = 60hz)
HSync us (Lines)
3.77 - Sync = 60.32 cycles
1.89 - Blank = 30.24 cycles
25.17 - RGB = 402.72 cycles
0.94 - Blank = 15.04 cycles
508 Cycles per line
VSync Start = 2 lines
Vsync blank = 32 lines
480 lines
VSync Blank = 11 lines
Total of 525 lines
*/
#include <SPI.h>
#include <avr/pgmspace.h>
#include <avr/sleep.h>
volatile unsigned int linecount;
#define vSyncLow PORTB &= ~(1 << 0);
#define vSyncHigh PORTB |= (1 << 0);
uint8_t tileData[34*21]; // 714 bytes
void setup()
{
set_sleep_mode(SLEEP_MODE_IDLE);
pinMode(11, OUTPUT);
pinMode(8, OUTPUT); // VZync = VGA Pin 14
pinMode(9, OUTPUT); // HZync = VGA Pin 13
digitalWrite(8, LOW);
digitalWrite(11, LOW);
SPI.begin();
SPI.setClockDivider(SPI_CLOCK_DIV2);
SPI.setDataMode(0x04);
memset(tileData,1,sizeof(tileData));
tileData[0] = tileData[3] = 0;
tileData[9] = tileData[12] = 2;
tileData[21] = tileData[21*3] = 0;
tileData[21+7] = tileData[(21+7)*3] = 3;
// Disable Arduino Timer0 and UART Timer
TCCR0A = TCCR0B = 0;
TIMSK0 = 0;
TCCR1A = _BV(COM1A1) | _BV(COM1A0) | _BV(WGM11);
TCCR1B = _BV(WGM12) | _BV(WGM13) | _BV(CS10); // No Prescalar
ICR1 = 508;
TIMSK1 = _BV(TOIE1); // Enable timer overflow interrupt
OCR1A = 60; // HSync Pulse
sei(); // enable global interrupts
}
uint8_t y = 0;
uint8_t y2 = 0;
uint8_t temp = 0;
int line21 = 0;
extern PROGMEM prog_uchar charData[];
#define topOffset 39
void loop()
{
if (linecount >= topOffset && line21 < (34*21))
{
sleep_mode();
temp = pgm_read_byte_near(charData + (tileData[0+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[1+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[2+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[3+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[4+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[5+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[6+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[7+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[8+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[9+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[10+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[11+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[12+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[13+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[14+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[15+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[16+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[17+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[18+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[19+line21]*7) + y);
SPDR = temp; temp = pgm_read_byte_near(charData + (tileData[20+line21]*7) + y);
SPDR = temp;
y2++;
if (y2 == 2)
{
y2 = 0;
y++;
if (y == 7)
{
y = 0; line21 += 21;
}
}
}
else if (linecount == 0)
{
y = y2 = temp = line21 = 0;
}
}
ISR(TIMER1_OVF_vect)
{
if (linecount == 0) vSyncLow;
if (linecount == 2) vSyncHigh;
if (++linecount == 525) linecount = 0;
}
And the symbols-test:
#include <avr/pgmspace.h>
PROGMEM prog_uchar charData[7*4] = {
B11000110,
B11000110,
B11100110,
B11101110,
B00111000,
B00010000,
B00000000,
B00010000,
B01101100,
B11000110,
B11000110,
B01101100,
B00111000,
B00000000,
B11111110,
B11111110,
B11111110,
B11111110,
B00111000,
B00010000,
B00000000,
B00010000,
B01111100,
B11111110,
B11111110,
B01111100,
B00111000,
B00000000};
Will try to check this tomorrow or later on.
Actually, the signal sync could be possible, but not any image. Handling 640x480 is already pushing the Arduino to its limits, really.
Great job.