WebSVN - Projects - Diff - Rev 274 and 296


#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 None (Bits WGM02 = 0, WGM01 = 0, WGM00 = 0)
    TCCR0A &= ~((1<<COM0A0)|(1<<COM0B0)|(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);
 
 
 
 
 
        // 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 274	Rev 296
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 "timer0.h"	5	#include "timer0.h"
6		6
7	volatile uint16_t CountMilliseconds = 0;	7	volatile uint16_t CountMilliseconds = 0;
8	DateTime_t SystemTime;	8	DateTime_t SystemTime;
9		9
10	#ifdef USE_FOLLOWME	10	#ifdef USE_FOLLOWME
11	volatile uint16_t BeepTime = 0;	11	volatile uint16_t BeepTime = 0;
12	volatile uint16_t BeepModulation = 0xFFFF;	12	volatile uint16_t BeepModulation = 0xFFFF;
13	#endif	13	#endif
14		14
15		15
16	/*****************************************************/	16	/*****************************************************/
17	/* Initialize Timer 0 */	17	/* Initialize Timer 0 */
18	/*****************************************************/	18	/*****************************************************/
19	// 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
20	// 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
21	void TIMER0_Init(void)	21	void TIMER0_Init(void)
22	{	22	{
23	uint8_t sreg = SREG;	23	uint8_t sreg = SREG;
24		24
25	// disable all interrupts before reconfiguration	25	// disable all interrupts before reconfiguration
26	cli();	26	cli();
27		27
28		28
29	// configure speaker port as output	29	// configure speaker port as output
30		30
31	#ifdef USE_FOLLOWME	31	#ifdef USE_FOLLOWME
32	// Speaker at PC7	32	// Speaker at PC7
33	DDRC \|= (1<<DDC7);	33	DDRC \|= (1<<DDC7);
34	PORTC &= ~(1<<PORTC7);	34	PORTC &= ~(1<<PORTC7);
35	#endif	35	#endif
36		36
37	// Timer/Counter 0 Control Register A	37	// Timer/Counter 0 Control Register A
38		38
39	// Waveform Generation Mode is Fast PWM (Bits WGM02 = 0, WGM01 = 1, WGM00 = 1)	-
40	// Clear OC0A on Compare Match, set OC0A at BOTTOM, noninverting PWM (Bits COM0A1 = 1, COM0A0 = 0)	-
41	// Clear OC0B on Compare Match, set OC0B at BOTTOM, (Bits COM0B1 = 1, COM0B0 = 0)	-
42	TCCR0A &= ~((1<<COM0A0)\|(1<<COM0B0));	39	// Waveform Generation None (Bits WGM02 = 0, WGM01 = 0, WGM00 = 0)
43	TCCR0A \|= (1<<COM0A1)\|(1<<COM0B1)\|(1<<WGM01)\|(1<<WGM00);	40	TCCR0A &= ~((1<<COM0A0)\|(1<<COM0B0)\|(1<<COM0A1)\|(1<<COM0B1)\|(1<<WGM01)\|(1<<WGM00));
44		41
45	// Timer/Counter 0 Control Register B	42	// Timer/Counter 0 Control Register B
46		43
47	// set clock devider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz	44	// set clock devider for timer 0 to SYSKLOCK/8 = 20MHz / 8 = 2.5MHz
48	// i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz	45	// i.e. the timer increments from 0x00 to 0xFF with an update rate of 2.5 MHz
49	// hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz	46	// hence the timer overflow interrupt frequency is 2.5 MHz / 256 = 9.765 kHz
50		47
51	// divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)	48	// divider 8 (Bits CS02 = 0, CS01 = 1, CS00 = 0)
52	TCCR0B &= ~((1<<FOC0A)\|(1<<FOC0B)\|(1<<WGM02));	49	TCCR0B &= ~((1<<FOC0A)\|(1<<FOC0B)\|(1<<WGM02));
53	TCCR0B = (TCCR0B & 0xF8)\|(0<<CS02)\|(1<<CS01)\|(0<<CS00);	50	TCCR0B = (TCCR0B & 0xF8)\|(0<<CS02)\|(1<<CS01)\|(0<<CS00);
54		-
55	// initialize the Output Compare Register A & B used for PWM generation on port PB3 & PB4	-
56	OCR0A = 0; // for PB3	-
57	OCR0B = 120; // for PB4	-
58		51
59	// init Timer/Counter 0 Register	52	// init Timer/Counter 0 Register
60	TCNT0 = 0;	53	TCNT0 = 0;
61		54
62	// Timer/Counter 0 Interrupt Mask Register	55	// Timer/Counter 0 Interrupt Mask Register
63	// enable timer overflow interrupt only	56	// enable timer overflow interrupt only
64	TIMSK0 &= ~((1<<OCIE0B)\|(1<<OCIE0A));	57	TIMSK0 &= ~((1<<OCIE0B)\|(1<<OCIE0A));
65	TIMSK0 \|= (1<<TOIE0);	58	TIMSK0 \|= (1<<TOIE0);
66		59
67		60
68	SystemTime.Year = 0;	61	SystemTime.Year = 0;
69	SystemTime.Month = 0;	62	SystemTime.Month = 0;
70	SystemTime.Day = 0;	63	SystemTime.Day = 0;
71	SystemTime.Hour = 0;	64	SystemTime.Hour = 0;
72	SystemTime.Min = 0;	65	SystemTime.Min = 0;
73	SystemTime.Sec = 0;	66	SystemTime.Sec = 0;
74	SystemTime.mSec = 0;	67	SystemTime.mSec = 0;
75	SystemTime.Valid = 0;	68	SystemTime.Valid = 0;
76		69
77	CountMilliseconds = 0;	70	CountMilliseconds = 0;
78		71
79		72
80	SREG = sreg;	73	SREG = sreg;
81	}	74	}
82		75
83		76
84		77
85	/*****************************************************/	78	/*****************************************************/
86	/* Interrupt Routine of Timer 0 */	79	/* Interrupt Routine of Timer 0 */
87	/*****************************************************/	80	/*****************************************************/
88	ISR(TIMER0_OVF_vect) // 9.765 kHz	81	ISR(TIMER0_OVF_vect) // 9.765 kHz
89	{	82	{
90	static uint8_t cnt = 0;	83	static uint8_t cnt = 0;
91	#ifdef USE_FOLLOWME	84	#ifdef USE_FOLLOWME
92	uint8_t Beeper_On = 0;	85	uint8_t Beeper_On = 0;
93	#endif	86	#endif
94		87
95	if(!cnt--) // every 10th run (9.765kHz/10 = 976Hz)	88	if(!cnt--) // every 10th run (9.765kHz/10 = 976Hz)
96	{	89	{
97	cnt = 9;	90	cnt = 9;
98	CountMilliseconds++; // increment millisecond counter	91	CountMilliseconds++; // increment millisecond counter
99	}	92	}
100		93
101	#ifdef USE_FOLLOWME	94	#ifdef USE_FOLLOWME
102	// beeper on if duration is not over	95	// beeper on if duration is not over
103	if(BeepTime)	96	if(BeepTime)
104	{	97	{
105	BeepTime--; // decrement BeepTime	98	BeepTime--; // decrement BeepTime
106	if(BeepTime & BeepModulation) Beeper_On = 1;	99	if(BeepTime & BeepModulation) Beeper_On = 1;
107	else Beeper_On = 0;	100	else Beeper_On = 0;
108	}	101	}
109	else // beeper off if duration is over	102	else // beeper off if duration is over
110	{	103	{
111	Beeper_On = 0;	104	Beeper_On = 0;
112	BeepModulation = 0xFFFF;	105	BeepModulation = 0xFFFF;
113	}	106	}
114		107
115	// if beeper is on	108	// if beeper is on
116	if(Beeper_On)	109	if(Beeper_On)
117	{	110	{
118	// set speaker port to high	111	// set speaker port to high
119	PORTC \|= (1<<PORTC7); // Speaker at PC7	112	PORTC \|= (1<<PORTC7); // Speaker at PC7
120	}	113	}
121	else // beeper is off	114	else // beeper is off
122	{	115	{
123	// set speaker port to low	116	// set speaker port to low
124	PORTC &= ~(1<<PORTC7);// Speaker at PC7	117	PORTC &= ~(1<<PORTC7);// Speaker at PC7
125	}	118	}
126	#endif	119	#endif
127	}	120	}
128		121
129		122
130	// -----------------------------------------------------------------------	123	// -----------------------------------------------------------------------
131	uint16_t SetDelay (uint16_t t)	124	uint16_t SetDelay (uint16_t t)
132	{	125	{
133	return(CountMilliseconds + t - 1);	126	return(CountMilliseconds + t - 1);
134	}	127	}
135		128
136	// -----------------------------------------------------------------------	129	// -----------------------------------------------------------------------
137	int8_t CheckDelay(uint16_t t)	130	int8_t CheckDelay(uint16_t t)
138	{	131	{
139	return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit	132	return(((t - CountMilliseconds) & 0x8000) >> 8); // check sign bit
140	}	133	}
141		134
142	// -----------------------------------------------------------------------	135	// -----------------------------------------------------------------------
143	void Delay_ms(uint16_t w)	136	void Delay_ms(uint16_t w)
144	{	137	{
145	unsigned int t_stop;	138	unsigned int t_stop;
146	t_stop = SetDelay(w);	139	t_stop = SetDelay(w);
147	while (!CheckDelay(t_stop));	140	while (!CheckDelay(t_stop));
148	}	141	}
149		142
150		143

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