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Diffstat (limited to 'Tacho_screen.c')
| -rw-r--r-- | Tacho_screen.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/Tacho_screen.c b/Tacho_screen.c new file mode 100644 index 0000000..df8d34c --- /dev/null +++ b/Tacho_screen.c @@ -0,0 +1,189 @@ +/* + * Tacho.c + * + * Created: 19.06.2014 15:33:40 + * Author: Jonas + */ + +#define F_CPU 1000000 +#include <avr/io.h> +#include <util/delay.h> +#include <avr/interrupt.h> + +#define _PRIM PORTC +#define _SEC PORTD + +#define _WHEEL_SIZE 207 + +//Define characters (negative) +#define _C1 0b10101111//0b01010000 +#define _C2 0b11001000//0b00110111 +#define _C3 0b10101000//0b00000000 +#define _C4 0b10100101//0b00000000 +#define _C5 0b10110000//0b00000000 +#define _C6 0b10010001//0b00000000 +#define _C7 0b10101110//0b00000000 +#define _C8 0b10000000//0b00000000 +#define _C9 0b10100000//0b00000000 +#define _C0 0b10000010//0b00000000 +#define _C_ 0b11111101 +#define _CCLEAR 255 + +uint32_t cntr; +unsigned int speed; + +ISR(TIMER0_OVF_vect) +{ + cntr++; +} + +inline void calcSpeed(void) +{ + float tmrSpeed = F_CPU / 256; + float tmrTime = 1 / tmrSpeed; + float comTime = tmrTime * cntr; + + float mps = (_WHEEL_SIZE / 100) / comTime; + + float kmph = mps * 3.6; + + speed = (int)kmph; +}//calcSpeed() + +inline void render(int _screen) +{ + char cNr[16]; + + int i1, i2; + + itoa(_screen, cNr, 10); //convert int to string for rendering + + if(_screen < 10) + { + i1 = 0; + i2 = 1; + cNr[1] = '0'; + } + else + { + i1 = 1; + i2 = 0; + } + + if(_screen > 99 || _screen < 0) + { + _SEC = _PRIM = _C_; + } + else + { + switch (cNr[i1]) //first character + { + case '0': + _PRIM = _C0; + PORTB &= ~(1<<PB2); + break; + case '1': + _PRIM = _C1; + PORTB &= ~(1<<PB2); + break; + case '2': + _PRIM = _C2; + PORTB |= (1<<PB2); + break; + case '3': + _PRIM = _C3; + PORTB &= ~(1<<PB2); + break; + case '4': + _PRIM = _C4; + PORTB &= ~(1<<PB2); + break; + case '5': + _PRIM = _C5; + PORTB &= ~(1<<PB2); + break; + case '6': + _PRIM = _C6; + PORTB &= ~(1<<PB2); + break; + case '7': + _PRIM = _C7; + PORTB &= ~(1<<PB2); + break; + case '8': + _PRIM = _C8; + PORTB &= ~(1<<PB2); + break; + case '9': + _PRIM = _C9; + PORTB &= ~(1<<PB2); + break; + } + + switch (cNr[i2])//second character + { + case '0': + _SEC = _C0; + break; + case '1': + _SEC = _C1; + break; + case '2': + _SEC = _C2; + break; + case '3': + _SEC = _C3; + break; + case '4': + _SEC = _C4; + break; + case '5': + _SEC = _C5; + break; + case '6': + _SEC = _C6; + break; + case '7': + _SEC = _C7; + break; + case '8': + _SEC = _C8; + break; + case '9': + _SEC = _C9; + break; + } + } +}//render() + +int main(void) +{ + TCCR0 = (1 << CS00); // Prescaler 1 + TIMSK = (1<<TOIE0); //Enable Overflowinterrupt + + cntr = 0; //counter for Timer + DDRC = DDRD = 255; // Output for scrren pins + DDRB |= (1<<PB2); + DDRB &= ~(1<<PB1); + + sei(); + + render(0); + + //PORTC = 0b01010000; + while(1)//main loop + { + while(PINB & (1 << PB1) && cntr < 30000){} // wait for reed + TCCR0 = ~(1 << CS00); //disable counter + cli(); //disable interrupts + calcSpeed(); + //reset all variables + cntr = 0; + TCNT0 = 0; + sei();//enable interrupts + TCCR0 = (1 << CS00); //enable counter + + render(speed);//render the calculated speed + _delay_ms(100); + } +}//main()
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