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Cleanup. Font writer included among examples
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This commit is contained in:
Jens True
2021-03-19 18:07:21 +01:00
parent 1936746a40
commit 1e99abecab
5 changed files with 352 additions and 14 deletions
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examples/WriteMCM/WriteMCM.ino Normal file
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// Code to copy a MCM font file to the Arduino + Max7456 OSD
//
// MAX7456_font Sketch
// at 9600 baud it take about 3min to download a mcm file
// http://www.maxim-ic.com/tools/evkit/index.cfm?EVKit=558
// max7456 evaluation kit software
#define DATAOUT 11//11-MOSI
#define DATAIN 12//12-MISO
#define SPICLOCK 13//13-sck
#define MAX7456SELECT 6 //6
#define USBSELECT 10//10-ss
#define VSYNC 2// INT0
//MAX7456 opcodes
#define VM0_reg 0x00
#define VM1_reg 0x01
#define DMM_reg 0x04
#define DMAH_reg 0x05
#define DMAL_reg 0x06
#define DMDI_reg 0x07
#define CMM_reg 0x08
#define CMAH_reg 0x09
#define CMAL_reg 0x0A
#define CMDI_reg 0x0B
#define STAT_reg 0xA0
//MAX7456 commands
#define CLEAR_display 0x04
#define CLEAR_display_vert 0x06
#define END_string 0xff
#define WRITE_nvr 0xa0
// with NTSC
#define ENABLE_display 0x08
#define ENABLE_display_vert 0x0c
#define MAX7456_reset 0x02
#define DISABLE_display 0x00
// with PAL
// all VM0_reg commands need bit 6 set
//#define ENABLE_display 0x48
//#define ENABLE_display_vert 0x4c
//#define MAX7456_reset 0x42
//#define DISABLE_display 0x40
#define WHITE_level_80 0x03
#define WHITE_level_90 0x02
#define WHITE_level_100 0x01
#define WHITE_level_120 0x00
#define MAX_font_rom 0xff
#define STATUS_reg_nvr_busy 0x20
#define NVM_ram_size 0x36
// with NTSC
#define MAX_screen_rows 0x0d //13
// with PAL
//#define MAX_screen_rows 0x10 //16
volatile byte screen_buffer[MAX_font_rom];
volatile byte character_bitmap[0x40];
volatile byte ascii_binary[0x08];
volatile byte bit_count;
volatile byte byte_count;
volatile int font_count;
volatile int incomingByte;
volatile int count;
//////////////////////////////////////////////////////////////
void setup()
{
byte spi_junk;
int x;
Serial.begin(38400);
Serial.flush();
digitalWrite(USBSELECT,HIGH); //disable USB chip
pinMode(MAX7456SELECT,OUTPUT);
digitalWrite(MAX7456SELECT,HIGH); //disable device
pinMode(DATAOUT, OUTPUT);
pinMode(DATAIN, INPUT);
pinMode(SPICLOCK,OUTPUT);
pinMode(VSYNC, INPUT);
// SPCR = 01010000
//interrupt disabled,spi enabled,msb 1st,master,clk low when idle,
//sample on leading edge of clk,system clock/4 rate (4 meg)
SPCR = (1<<SPE)|(1<<MSTR);
spi_junk=SPSR;
spi_junk=SPDR;
delay(250);
// force soft reset on Max7456
digitalWrite(MAX7456SELECT,LOW);
spi_transfer(VM0_reg);
spi_transfer(MAX7456_reset);
digitalWrite(MAX7456SELECT,HIGH);
delay(500);
// set all rows to same character white level, 90%
digitalWrite(MAX7456SELECT,LOW);
for (x = 0; x < MAX_screen_rows; x++)
{
spi_transfer(x + 0x10);
spi_transfer(WHITE_level_90);
}
// make sure the Max7456 is enabled
spi_transfer(VM0_reg);
spi_transfer(ENABLE_display);
digitalWrite(MAX7456SELECT,HIGH);
incomingByte = 0;
count = 0;
bit_count = 0;
byte_count = 0;
font_count = 0;
//display all 256 internal MAX7456 characters
for (x = 0; x < MAX_font_rom; x++)
{
screen_buffer[x] = x;
}
count = MAX_font_rom;
write_new_screen();
Serial.println("Ready for text file download");
Serial.println("");
delay(100);
}
//////////////////////////////////////////////////////////////
void loop()
{
byte x;
if (Serial.available() > 0)
{
// read the incoming byte:
incomingByte = Serial.read();
switch(incomingByte) // parse and decode mcm file
{
case 0x0d: // carridge return, end of line
//Serial.println("cr");
if (bit_count == 8 && (ascii_binary[0] == 0x30 || ascii_binary[0] == 0x31))
{
// turn 8 ascii binary bytes to single byte '01010101' = 0x55
// fill in 64 bytes of character data
character_bitmap[byte_count] = decode_ascii_binary();
byte_count++;
bit_count = 0;
}
else
bit_count = 0;
break;
case 0x0a: // line feed, ignore
//Serial.println("ln");
break;
case 0x30: // ascii '0'
case 0x31: // ascii '1'
ascii_binary[bit_count] = incomingByte;
bit_count++;
break;
default:
break;
}
}
// we have one completed character
// write the character to NVM
if(byte_count == 64)
{
write_NVM();
byte_count = 0;
font_count++;
}
// we have burned all 256 characters in NVM
if(font_count == 256)
{
font_count = 0;
// force soft reset on Max7456
digitalWrite(MAX7456SELECT,LOW);
spi_transfer(VM0_reg);
spi_transfer(MAX7456_reset);
digitalWrite(MAX7456SELECT,HIGH);
delay(500);
// display all 256 new internal MAX7456 characters
for (x = 0; x < MAX_font_rom; x++)
{
screen_buffer[x] = x;
}
count = MAX_font_rom;
write_new_screen();
Serial.println("");
Serial.println("Done with file download");
}
}
//////////////////////////////////////////////////////////////
byte spi_transfer(volatile byte data)
{
SPDR = data; // Start the transmission
while (!(SPSR & (1<<SPIF))) // Wait the end of the transmission
{
};
return SPDR; // return the received byte
}
//////////////////////////////////////////////////////////////
void write_new_screen()
{
int x, local_count;
byte char_address_hi, char_address_lo;
byte screen_char;
local_count = count;
char_address_hi = 0;
char_address_lo = 60; // start on third line
//Serial.println("write_new_screen");
// clear the screen
digitalWrite(MAX7456SELECT,LOW);
spi_transfer(DMM_reg);
spi_transfer(CLEAR_display);
digitalWrite(MAX7456SELECT,HIGH);
// disable display
digitalWrite(MAX7456SELECT,LOW);
spi_transfer(VM0_reg);
spi_transfer(DISABLE_display);
spi_transfer(DMM_reg); //dmm
//spi_transfer(0x21); //16 bit trans background
spi_transfer(0x01); //16 bit trans w/o background
spi_transfer(DMAH_reg); // set start address high
spi_transfer(char_address_hi);
spi_transfer(DMAL_reg); // set start address low
spi_transfer(char_address_lo);
x = 0;
while(local_count) // write out full screen
{
screen_char = screen_buffer[x];
spi_transfer(DMDI_reg);
spi_transfer(screen_char);
x++;
local_count--;
}
spi_transfer(DMDI_reg);
spi_transfer(END_string);
spi_transfer(VM0_reg); // turn on screen next vertical
spi_transfer(ENABLE_display_vert);
digitalWrite(MAX7456SELECT,HIGH);
}
//////////////////////////////////////////////////////////////
byte decode_ascii_binary()
{
byte ascii_byte;
ascii_byte = 0;
if (ascii_binary[0] == 0x31) // ascii '1'
ascii_byte = ascii_byte + 128;
if (ascii_binary[1] == 0x31)
ascii_byte = ascii_byte + 64;
if (ascii_binary[2] == 0x31)
ascii_byte = ascii_byte + 32;
if (ascii_binary[3] == 0x31)
ascii_byte = ascii_byte + 16;
if (ascii_binary[4] == 0x31)
ascii_byte = ascii_byte + 8;
if (ascii_binary[5] == 0x31)
ascii_byte = ascii_byte + 4;
if (ascii_binary[6] == 0x31)
ascii_byte = ascii_byte + 2;
if (ascii_binary[7] == 0x31)
ascii_byte = ascii_byte + 1;
//Serial.print(ascii_byte, HEX);
return(ascii_byte);
}
//////////////////////////////////////////////////////////////
void write_NVM()
{
byte x;
byte char_address_hi, char_address_lo;
byte screen_char;
char_address_hi = font_count;
char_address_lo = 0;
//Serial.println("write_new_screen");
// disable display
digitalWrite(MAX7456SELECT,LOW);
spi_transfer(VM0_reg);
spi_transfer(DISABLE_display);
spi_transfer(CMAH_reg); // set start address high
spi_transfer(char_address_hi);
for(x = 0; x < NVM_ram_size; x++) // write out 54 (out of 64) bytes of character to shadow ram
{
screen_char = character_bitmap[x];
spi_transfer(CMAL_reg); // set start address low
spi_transfer(x);
spi_transfer(CMDI_reg);
spi_transfer(screen_char);
}
// transfer a 54 bytes from shadow ram to NVM
spi_transfer(CMM_reg);
spi_transfer(WRITE_nvr);
// wait until bit 5 in the status register returns to 0 (12ms)
while ((spi_transfer(STAT_reg) & STATUS_reg_nvr_busy) != 0x00);
spi_transfer(VM0_reg); // turn on screen next vertical
spi_transfer(ENABLE_display_vert);
digitalWrite(MAX7456SELECT,HIGH);
}