Rev 274 | Go to most recent revision | Only display areas with differences | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
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 |