finga/clock_generator
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Disable CKDIV8 and adapt to clock div. factor

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Configure fuses for the `fuses` target in Makefile to disable
`CKDIV8`. Adapt PWM generation in `lcd_update_backlight()` to new
clock division factor, as well as interrupt handling, debouncing and
dechattering.

This also enables partially lower PWM frequencies (between off and
former lowest PWM setting) for a dimmer lcd backlight.
This commit is contained in:
finga 2021-09-21 18:40:49 +02:00
parent c48e4a31ab
commit bd217ce6e7
2 changed files with 26 additions and 17 deletions
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3
firmware/src/Makefile
View file

@ -9,6 +9,7 @@ EEP := main.eep
BIN := main.elf
OBJ := main.o
LOW_FUSE := 0xE2
HIGH_FUSE := 0xD6
SHELL := sh
@ -42,7 +43,7 @@ eeprom: $(EEP) size
$(AVRDUDE) -p $(MCU) -c $(PROGRAMMER) -U eeprom:w:$<:a
fuses:
$(AVRDUDE) -p $(MCU) -c $(PROGRAMMER) -U hfuse:w:$(HIGH_FUSE):m
$(AVRDUDE) -p $(MCU) -c $(PROGRAMMER) -U lfuse:w:$(LOW_FUSE):m -U hfuse:w:$(HIGH_FUSE):m
clean:
$(RM) $(TARGET) $(EEP) $(BIN) $(OBJ)

38
firmware/src/main.c
View file

@ -194,10 +194,20 @@ static void lcd_update_backlight(void) {
case 0:
DDRD &= (0 << PD5);
break;
default:
case 1:
case 2:
case 3:
case 4:
case 5:
TCCR0B = 0x0C; // prescaler = 256;
DDRD |= (1 << PD5);
OCR0B = value_backlight - 1;
break;
default:
TCCR0B = 0x0B; // prescaler = 64;
DDRD |= (1 << PD5);
OCR0B = value_backlight - 4;
break;
}
}
@ -598,7 +608,7 @@ ISR(PCINT0_vect) {
}
// TODO: proper dechattering
_delay_us(100);
_delay_ms(3);
sei();
}
@ -607,19 +617,19 @@ ISR(PCINT0_vect) {
ISR(PCINT1_vect) {
cli();
if (PINC & (1 << PC0)) { // release
TCCR1B &= (0 << CS11) & (0 << CS10); // Disable Timer/Counter1
if (TCNT1 != 0) {
if (PINC & (1 << PC0)) { // Release
if (TCCR1B & (1 << CS10)) // If release before hold
update_state(click); // Switch to selected state
TCCR1B &= (0 << CS11) & (0 << CS10); // Disable Timer/Counter1
} else { // Press
TCNT1 = 0;
}
} else { // press
if (!(TCCR1B & (1 << CS10)))
TCCR1B |= (1 << CS11) | (1 << CS10); // Enable Timer/Counter1
}
// TODO: proper debouncing
_delay_us(70);
// TODO: Proper debouncing
_delay_ms(3);
sei();
}
@ -629,7 +639,6 @@ ISR(TIMER1_COMPA_vect) {
cli();
TCCR1B &= (0 << CS11) & (0 << CS10); // Disable Timer/Counter1
TCNT1 = 0;
update_state(hold);
sei();
@ -643,8 +652,7 @@ int main(void) {
// Init backlight: FastPWM: 1.25kHz
// TODO: Try to get the backlit even more dim
TCCR0A |= (1 << WGM01) | (1 << WGM00) | (1 << COM0B1);
TCCR0B |= (1 << CS01) | (1 << WGM02); // prescaler = 8;
OCR0A = 100;
OCR0A = 255;
lcd_update_backlight();
// SPI setup
@ -661,13 +669,13 @@ int main(void) {
PCICR |= (1 << PCIE1);
PCMSK1 |= (1 << PCINT8);
// Timer1 setup to recognize held button
OCR1A = 8192;
// Timer/Counter1 setup to recognize held button
OCR1A = 65535;
TIMSK1 |= (1 << OCIE1A); // Enable match compare A
// Show splash screen and load the menu
lcd_splash();
_delay_ms(250);
_delay_ms(2000);
change_state(current_state);
// Enable interrupts