WebSVN - Projects - Diff - Rev 271 and 274


#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
 
#include "timer0.h"
 
volatile uint16_t CountMilliseconds = 0;
DateTime_t SystemTime;
 
#ifdef USE_FOLLOWME
volatile uint16_t BeepTime = 0;
volatile uint16_t BeepModulation = 0xFFFF;
#endif
 
 
/*****************************************************/
/*              Initialize Timer 0                   */
/*****************************************************/
// timer 0 is used for the PWM generation to control the offset voltage at the air pressure sensor
// Its overflow interrupt routine is used to generate the beep signal and the flight control motor update rate
void TIMER0_Init(void)
{
        uint8_t sreg = SREG;
 
        // disable all interrupts before reconfiguration
        cli();
 
 
        // configure speaker port as output
 
        #ifdef USE_FOLLOWME
        // Speaker at PC7
        DDRC |= (1<<DDC7);
        PORTC &= ~(1<<PORTC7);
        #endif
 
        // Timer/Counter 0 Control Register A
 
        // Waveform Generation Mode is Fast PWM (Bits WGM02 = 0, WGM01 = 1, WGM00 = 1)
    // Clear OC0A on Compare Match, set OC0A at BOTTOM, noninverting PWM (Bits COM0A1 = 1, COM0A0 = 0)
    // Clear OC0B on Compare Match, set OC0B at BOTTOM, (Bits COM0B1 = 1, COM0B0 = 0)
    TCCR0A &= ~((1<<COM0A0)|(1<<COM0B0));
    TCCR0A |= (1<<COM0A1)|(1<<COM0B1)|(1<<WGM01)|(1<<WGM00);
 
        // Timer/Counter 0 Control Register B
 
        // set clock devider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz
        // i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
        // hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz
 
        // divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
        TCCR0B &= ~((1<<FOC0A)|(1<<FOC0B)|(1<<WGM02));
    TCCR0B = (TCCR0B & 0xF8)|(0<<CS02)|(1<<CS01)|(0<<CS00);
 
        // initialize the Output Compare Register A & B used for PWM generation on port PB3 & PB4
    OCR0A =  0;  // for PB3
    OCR0B = 120; // for PB4
 
        // init Timer/Counter 0 Register
    TCNT0 = 0;
 
        // Timer/Counter 0 Interrupt Mask Register
        // enable timer overflow interrupt only
        TIMSK0 &= ~((1<<OCIE0B)|(1<<OCIE0A));
        TIMSK0 |= (1<<TOIE0);
 
 
        SystemTime.Year = 0;
        SystemTime.Month = 0;
        SystemTime.Day = 0;
        SystemTime.Hour = 0;
        SystemTime.Min = 0;
        SystemTime.Sec = 0;
        SystemTime.mSec = 0;
        SystemTime.Valid = 0;
 
        CountMilliseconds = 0;
 
 
        SREG = sreg;
}
 
 
 
/*****************************************************/
/*          Interrupt Routine of Timer 0             */
/*****************************************************/
ISR(TIMER0_OVF_vect)    // 9.765 kHz
{
    static uint8_t cnt = 0;
    #ifdef USE_FOLLOWME
    uint8_t Beeper_On = 0;
        #endif
 
        if(!cnt--) // every 10th run (9.765kHz/10 = 976Hz)
        {
                cnt = 9;
                CountMilliseconds++; // increment millisecond counter
        }
 
         #ifdef USE_FOLLOWME
        // beeper on if duration is not over
        if(BeepTime)
        {
                BeepTime--; // decrement BeepTime
                if(BeepTime & BeepModulation) Beeper_On = 1;
                else Beeper_On = 0;
        }
        else // beeper off if duration is over
        {
                Beeper_On = 0;
                BeepModulation = 0xFFFF;
        }
 
        // if beeper is on
        if(Beeper_On)
        {
                // set speaker port to high
                PORTC |= (1<<PORTC7); // Speaker at PC7
        }
        else // beeper is off
        {
                // set speaker port to low
                PORTC &= ~(1<<PORTC7);// Speaker at PC7
        }
        #endif
}
 
 
// -----------------------------------------------------------------------
uint16_t SetDelay (uint16_t t)
{
  return(CountMilliseconds + t - 1);
}
 
// -----------------------------------------------------------------------
int8_t CheckDelay(uint16_t t)
{
  return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit
}
 
// -----------------------------------------------------------------------
void Delay_ms(uint16_t w)
{
 unsigned int t_stop;
 t_stop = SetDelay(w);
 while (!CheckDelay(t_stop));
}
 
 

Rev 271	Rev 274
1	#include <inttypes.h>	1	#include <inttypes.h>
2	#include <avr/io.h>	2	#include <avr/io.h>
3	#include <avr/interrupt.h>	3	#include <avr/interrupt.h>
4		4
5	#include "main.h"	5	#include "timer0.h"
-		6
-		7	volatile uint16_t CountMilliseconds = 0;
6		8	DateTime_t SystemTime;
7	volatile uint16_t CountMilliseconds = 0;	9
8	#ifdef USE_FOLLOWME	10	#ifdef USE_FOLLOWME
9	volatile uint16_t BeepTime = 0;	11	volatile uint16_t BeepTime = 0;
10	volatile uint16_t BeepModulation = 0xFFFF;	12	volatile uint16_t BeepModulation = 0xFFFF;
11	#endif	13	#endif
12		14
13		15
14	/*****************************************************/	16	/*****************************************************/
15	/* Initialize Timer 0 */	17	/* Initialize Timer 0 */
16	/*****************************************************/	18	/*****************************************************/
17	// timer 0 is used for the PWM generation to control the offset voltage at the air pressure sensor	19	// timer 0 is used for the PWM generation to control the offset voltage at the air pressure sensor
18	// Its overflow interrupt routine is used to generate the beep signal and the flight control motor update rate	20	// Its overflow interrupt routine is used to generate the beep signal and the flight control motor update rate
19	void TIMER0_Init(void)	21	void TIMER0_Init(void)
20	{	22	{
21	uint8_t sreg = SREG;	23	uint8_t sreg = SREG;
22		24
23	// disable all interrupts before reconfiguration	25	// disable all interrupts before reconfiguration
24	cli();	26	cli();
25		27
26		28
27	// configure speaker port as output	29	// configure speaker port as output
28		30
29	#ifdef USE_FOLLOWME	31	#ifdef USE_FOLLOWME
30	// Speaker at PC7	32	// Speaker at PC7
31	DDRC \|= (1<<DDC7);	33	DDRC \|= (1<<DDC7);
32	PORTC &= ~(1<<PORTC7);	34	PORTC &= ~(1<<PORTC7);
33	#endif	35	#endif
34		36
35	// Timer/Counter 0 Control Register A	37	// Timer/Counter 0 Control Register A
36		38
37	// Waveform Generation Mode is Fast PWM (Bits WGM02 = 0, WGM01 = 1, WGM00 = 1)	39	// Waveform Generation Mode is Fast PWM (Bits WGM02 = 0, WGM01 = 1, WGM00 = 1)
38	// Clear OC0A on Compare Match, set OC0A at BOTTOM, noninverting PWM (Bits COM0A1 = 1, COM0A0 = 0)	40	// Clear OC0A on Compare Match, set OC0A at BOTTOM, noninverting PWM (Bits COM0A1 = 1, COM0A0 = 0)
39	// Clear OC0B on Compare Match, set OC0B at BOTTOM, (Bits COM0B1 = 1, COM0B0 = 0)	41	// Clear OC0B on Compare Match, set OC0B at BOTTOM, (Bits COM0B1 = 1, COM0B0 = 0)
40	TCCR0A &= ~((1<<COM0A0)\|(1<<COM0B0));	42	TCCR0A &= ~((1<<COM0A0)\|(1<<COM0B0));
41	TCCR0A \|= (1<<COM0A1)\|(1<<COM0B1)\|(1<<WGM01)\|(1<<WGM00);	43	TCCR0A \|= (1<<COM0A1)\|(1<<COM0B1)\|(1<<WGM01)\|(1<<WGM00);
42		44
43	// Timer/Counter 0 Control Register B	45	// Timer/Counter 0 Control Register B
44		46
45	// set clock devider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz	47	// set clock devider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz
46	// i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz	48	// i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
47	// hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz	49	// hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz
48		50
49	// divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)	51	// divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
50	TCCR0B &= ~((1<<FOC0A)\|(1<<FOC0B)\|(1<<WGM02));	52	TCCR0B &= ~((1<<FOC0A)\|(1<<FOC0B)\|(1<<WGM02));
51	TCCR0B = (TCCR0B & 0xF8)\|(0<<CS02)\|(1<<CS01)\|(0<<CS00);	53	TCCR0B = (TCCR0B & 0xF8)\|(0<<CS02)\|(1<<CS01)\|(0<<CS00);
52		54
53	// initialize the Output Compare Register A & B used for PWM generation on port PB3 & PB4	55	// initialize the Output Compare Register A & B used for PWM generation on port PB3 & PB4
54	OCR0A = 0; // for PB3	56	OCR0A = 0; // for PB3
55	OCR0B = 120; // for PB4	57	OCR0B = 120; // for PB4
56		58
57	// init Timer/Counter 0 Register	59	// init Timer/Counter 0 Register
58	TCNT0 = 0;	60	TCNT0 = 0;
59		61
60	// Timer/Counter 0 Interrupt Mask Register	62	// Timer/Counter 0 Interrupt Mask Register
61	// enable timer overflow interrupt only	63	// enable timer overflow interrupt only
62	TIMSK0 &= ~((1<<OCIE0B)\|(1<<OCIE0A));	64	TIMSK0 &= ~((1<<OCIE0B)\|(1<<OCIE0A));
63	TIMSK0 \|= (1<<TOIE0);	65	TIMSK0 \|= (1<<TOIE0);
-		66
-		67
-		68	SystemTime.Year = 0;
-		69	SystemTime.Month = 0;
-		70	SystemTime.Day = 0;
-		71	SystemTime.Hour = 0;
-		72	SystemTime.Min = 0;
-		73	SystemTime.Sec = 0;
-		74	SystemTime.mSec = 0;
-		75	SystemTime.Valid = 0;
-		76
-		77	CountMilliseconds = 0;
-		78
64		79
65	SREG = sreg;	80	SREG = sreg;
66	}	81	}
67		82
68		83
69		84
70	/*****************************************************/	85	/*****************************************************/
71	/* Interrupt Routine of Timer 0 */	86	/* Interrupt Routine of Timer 0 */
72	/*****************************************************/	87	/*****************************************************/
73	ISR(TIMER0_OVF_vect) // 9.765 kHz	88	ISR(TIMER0_OVF_vect) // 9.765 kHz
74	{	89	{
75	static uint8_t cnt = 0;	90	static uint8_t cnt = 0;
76	#ifdef USE_FOLLOWME	91	#ifdef USE_FOLLOWME
77	uint8_t Beeper_On = 0;	92	uint8_t Beeper_On = 0;
78	#endif	93	#endif
79		94
80	if(!cnt--) // every 10th run (9.765kHz/10 = 976Hz)	95	if(!cnt--) // every 10th run (9.765kHz/10 = 976Hz)
81	{	96	{
82	cnt = 9;	97	cnt = 9;
83	CountMilliseconds++; // increment millisecond counter	98	CountMilliseconds++; // increment millisecond counter
84	}	99	}
85		100
86	#ifdef USE_FOLLOWME	101	#ifdef USE_FOLLOWME
87	// beeper on if duration is not over	102	// beeper on if duration is not over
88	if(BeepTime)	103	if(BeepTime)
89	{	104	{
90	BeepTime--; // decrement BeepTime	105	BeepTime--; // decrement BeepTime
91	if(BeepTime & BeepModulation) Beeper_On = 1;	106	if(BeepTime & BeepModulation) Beeper_On = 1;
92	else Beeper_On = 0;	107	else Beeper_On = 0;
93	}	108	}
94	else // beeper off if duration is over	109	else // beeper off if duration is over
95	{	110	{
96	Beeper_On = 0;	111	Beeper_On = 0;
97	BeepModulation = 0xFFFF;	112	BeepModulation = 0xFFFF;
98	}	113	}
99		114
100	// if beeper is on	115	// if beeper is on
101	if(Beeper_On)	116	if(Beeper_On)
102	{	117	{
103	// set speaker port to high	118	// set speaker port to high
104	PORTC \|= (1<<PORTC7); // Speaker at PC7	119	PORTC \|= (1<<PORTC7); // Speaker at PC7
105	}	120	}
106	else // beeper is off	121	else // beeper is off
107	{	122	{
108	// set speaker port to low	123	// set speaker port to low
109	PORTC &= ~(1<<PORTC7);// Speaker at PC7	124	PORTC &= ~(1<<PORTC7);// Speaker at PC7
110	}	125	}
111	#endif	126	#endif
112	}	127	}
113		128
114		129
115	// -----------------------------------------------------------------------	130	// -----------------------------------------------------------------------
116	uint16_t SetDelay (uint16_t t)	131	uint16_t SetDelay (uint16_t t)
117	{	132	{
118	return(CountMilliseconds + t - 1);	133	return(CountMilliseconds + t - 1);
119	}	134	}
120		135
121	// -----------------------------------------------------------------------	136	// -----------------------------------------------------------------------
122	int8_t CheckDelay(uint16_t t)	137	int8_t CheckDelay(uint16_t t)
123	{	138	{
124	return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit	139	return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit
125	}	140	}
126		141
127	// -----------------------------------------------------------------------	142	// -----------------------------------------------------------------------
128	void Delay_ms(uint16_t w)	143	void Delay_ms(uint16_t w)
129	{	144	{
130	unsigned int t_stop;	145	unsigned int t_stop;
131	t_stop = SetDelay(w);	146	t_stop = SetDelay(w);
132	while (!CheckDelay(t_stop));	147	while (!CheckDelay(t_stop));
133	}	148	}
134		149
135		150

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