finga/clock_generator
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Interact with the display

Browse source 
Enable the SPI bus to configure the display and program its ram. For
that the fastest available SPI clock is used. To configure the display
a minimal config is used which is not identical but similar to the
displays datasheet. The display can only be filled columnwise so far.
This commit is contained in:
finga 2021-02-27 02:26:57 +01:00
parent 0065fb630f
commit 7f7d7b628a
2 changed files with 66 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
firmware/src/Makefile
View file

@ -24,7 +24,7 @@ $(BIN): $(OBJ)
$(CC) $(CFLAGS) $< -o $@
%.o: %.c
$(CC) $(CFLAGS) -Os -c $< -o $@
$(CC) $(CFLAGS) -c $< -o $@
.PHONY: flash clean check size

65
firmware/src/main.c
View file

@ -4,6 +4,67 @@
#include <util/delay.h>
#include <stdbool.h>
#define SPI_PORT PORTB
#define SPI_DDR DDRB
#define SPI_SCK PB5
#define SPI_MOSI PB3
#define SPI_SS PB2
#define LCD_CD PB6
#define LCD_RST PB1
void spi_init(void) {
SPI_DDR |= (1 << SPI_SCK) | (1 << SPI_MOSI) | (1 << SPI_SS);
SPI_PORT |= (1 << SPI_SS);
SPCR = (1 << SPE) | (1 << MSTR);
SPSR = (1 << SPI2X);
}
uint8_t spi_byte(uint8_t data) {
SPDR = data;
while(!(SPSR & (1 << SPIF)));
return SPDR;
}
void lcd_write(uint8_t data) {
SPI_PORT &= ~(1 << SPI_SS);
spi_byte(data);
SPI_PORT |= (1 << SPI_SS);
}
void lcd_init(void) {
SPI_DDR |= (1 << LCD_CD) | (1 << LCD_RST);
_delay_ms(1);
SPI_PORT |= (1 << LCD_RST);
_delay_ms(5);
lcd_write(0x40); // (6) Set Scroll Line: Display start line 0
lcd_write(0xA1); // (13) Set SEG direction: SEG reverse
lcd_write(0xC0); // (14) Set COM direction: Normal COM0 - COM63
lcd_write(0xA6); // (11) Set Inverse Display: Display inverse off
lcd_write(0xA2); // (17) Set LCD Bias Ratio: Set Bias 1/9 (Duty 1/65)
lcd_write(0x2F); // (5) Set Power Control: Booster, Regulator and Follower on
lcd_write(0x27); // (8) Set VLCD Resistor Ratio: Set Contrast
lcd_write(0x81); // (9) Set Electronic Volume: Set Contrast
lcd_write(0x10); // (9) Set Electronic Volume: Set Contrast
lcd_write(0xAF); // (12) Set Display Enable: Display on
}
void lcd_fill(uint8_t data) {
for (uint8_t i = 0; i < 8; i++) {
SPI_PORT &= ~(1 << LCD_CD);
lcd_write(0x00);
lcd_write(0x10);
lcd_write(0xB0 + i); // page address 0 + i
SPI_PORT |= (1 << LCD_CD);
for (uint8_t j = 0; j < 102; j++) {
lcd_write(data);
}
}
}
int main(void) {
// FastPWM: 1.25kHz
TCCR0A = (1 << WGM01) | (1 << WGM00) | (1 << COM0B1);
@ -14,6 +75,10 @@ int main(void) {
bool reverse = 0;
spi_init();
lcd_init();
lcd_fill(0xFF);
while (1) {
_delay_ms(1);