76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
#include <avr/io.h>
|
||
|
||
// #define FIRST_LETTER_IMPL(x) #x[0]
|
||
// #define FIRST_LETTER(x) FIRST_LETTER_IMPL(x)
|
||
// #define PORT_LETTER(PIN) FIRST_LETTER(PIN)
|
||
|
||
// global registers
|
||
#define SET(register, bit) register |= 1 << bit
|
||
#define CLEAR(register, bit) register &= ~(1 << bit)
|
||
#define TEST(register, bit) register & 1 << bit
|
||
#define TOGGLE(register, bit) register ^= 1 << bit
|
||
|
||
// actions on ports
|
||
#define TEST_PIN(port, bit) TEST(PIN ## port, bit)
|
||
#define TOGGLE_PIN(port, bit) SET(PIN ## port, bit)
|
||
#define MODE_INPUT(port, bit) CLEAR(DDR ## port, bit)
|
||
#define MODE_OUTPUT(port, bit) SET(DDR ## port, bit)
|
||
#define IS_PIN_SET(port, bit) (TEST_PIN(port, bit)) == 0
|
||
#define IS_PIN_CLEAR(port, bit) (TEST_PIN(port, bit)) == 1
|
||
#define TURN_ON(_PORT, BIT) SET(PORT ## _PORT, BIT)
|
||
#define TURN_OFF(_PORT, BIT) CLEAR(PORT ## _PORT, BIT)
|
||
|
||
// LEDs
|
||
#define TURN_ON_LED(bit) SET(PORTB, bit)
|
||
#define TURN_OFF_LED(bit) CLEAR(PORTB, bit)
|
||
#define TOGGLE_LED(led) TOGGLE_PIN(B, led)
|
||
|
||
// ELEMENTS
|
||
#define D1 0
|
||
#define D2 1
|
||
#define D3 2
|
||
#define D4 4
|
||
#define SW1 2
|
||
#define SW2 4
|
||
|
||
// TIME
|
||
#define PRESCALE_VALUE 1024
|
||
#if (PRESCALE_VALUE == 1)
|
||
#define PRESCALE_SET (1 << CS10)
|
||
#elif (PRESCALE_VALUE == 8)
|
||
#define PRESCALE_SET (1 << CS11)
|
||
#elif (PRESCALE_VALUE == 64)
|
||
#define PRESCALE_SET (1 << CS10) | (1 << CS11)
|
||
#elif (PRESCALE_VALUE == 256)
|
||
#define PRESCALE_SET (1 << CS12)
|
||
#elif (PRESCALE_VALUE == 1024)
|
||
#define PRESCALE_SET (1 << CS10) | (1 << CS12)
|
||
#endif
|
||
#define TIME_MS(ms) (((F_CPU / PRESCALE_VALUE) * ms) / 1000)
|
||
|
||
int main() {
|
||
MODE_OUTPUT(B, D2);
|
||
|
||
TCCR1B |= (1 << WGM12); // set timer in CTC (Clear Time on Compare) mode
|
||
// -> Table 16-4 : use bit WGM12 to set mode ctc
|
||
// -> 16.11.2 : bit WGM12 is located in register TCCR1B
|
||
|
||
TCCR1A |= (1 << COM1A0 ) ; // Enable timer 1 Compare Output channel A in toggle mode
|
||
// -> Table 14-3 : alternate functions for PORTB1 is OC1A (Timer/Counter1 Output Compare Match A Output)
|
||
// -> 14.3.1 : OC1A/PCINT1 – Port B, Bit 1
|
||
|
||
OCR1A = TIME_MS(500); // set CTC compare value
|
||
// -> Table 16-4 : the value to reset the timer is the Output Compare Registers OCR1A
|
||
|
||
TCCR1B |= (PRESCALE_SET);
|
||
|
||
while(1) {
|
||
continue;
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
|