Rev 886 | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
| Rev 886 | Rev 907 | ||
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| 1 | #include <avr/io.h> |
1 | #include <avr/io.h> |
| 2 | #include <stdlib.h> |
2 | #include <stdlib.h> |
| 3 | #include <inttypes.h> |
3 | #include <inttypes.h> |
| 4 | #include "timer0.h" |
4 | #include "timer0.h" |
| 5 | #include "uart.h" |
- | |
| 6 | #include "fc.h" |
5 | #include "fc.h" |
| 7 | #include "rc.h" |
6 | #include "rc.h" |
| 8 | #include "eeprom.h" |
7 | #include "eeprom.h" |
| 9 | #include "mk3mag.h" |
8 | #include "mk3mag.h" |
| Line 39... | Line 38... | ||
| 39 | // in other words 100us/° with a +1ms offset. |
38 | // in other words 100us/° with a +1ms offset. |
| 40 | // The signal goes low for 65ms between pulses, |
39 | // The signal goes low for 65ms between pulses, |
| 41 | // so the cycle time is 65mS + the pulse width. |
40 | // so the cycle time is 65mS + the pulse width. |
| Line 42... | Line 41... | ||
| 42 | 41 | ||
| - | 42 | // pwm is high |
|
| 43 | // pwm is high |
43 | |
| 44 | if(PINC & (1<<PINC4)) |
44 | if(PINC & (1<<PINC4)) |
| 45 | { // If PWM signal is high increment PWM high counter |
45 | { // If PWM signal is high increment PWM high counter |
| 46 | // This counter is incremented by a periode of 102.4us, |
46 | // This counter is incremented by a periode of 102.4us, |
| 47 | // i.e. the resoluton of pwm coded heading is approx. 1 deg. |
47 | // i.e. the resoluton of pwm coded heading is approx. 1 deg. |
| Line 54... | Line 54... | ||
| 54 | PWMCount = 0; // reset PWM Counter |
54 | PWMCount = 0; // reset PWM Counter |
| 55 | } |
55 | } |
| Line 56... | Line 56... | ||
| 56 | 56 | ||
| 57 | } |
57 | } |
| 58 | else // pwm is low |
58 | else // pwm is low |
| 59 | { // ignore pwm values values of 0 and higher than 37 ms |
59 | { // ignore pwm values values of 0 and higher than 37 ms; |
| 60 | if((PWMCount) && (PWMCount < 362)) // 362 * 102.4us = 37.0688 ms |
60 | if((PWMCount) && (PWMCount < 362)) // 362 * 102.4us = 37.0688 ms |
| 61 | { |
61 | { |
| 62 | if(PWMCount <10) CompassHeading = 0; |
62 | if(PWMCount <10) CompassHeading = 0; |
| 63 | else CompassHeading = ((uint32_t)(PWMCount - 10) * 1049L)/1024; // correct timebase and offset |
63 | else CompassHeading = ((uint32_t)(PWMCount - 10) * 1049L)/1024; // correct timebase and offset |
| 64 | CompassOffCourse = ((540 + CompassHeading - CompassCourse) % 360) - 180; |
64 | CompassOffCourse = ((540 + CompassHeading - CompassCourse) % 360) - 180; |
| 65 | PWMTimeout = 12; // if 12 periodes long no valid PWM was detected the data are invalid |
65 | PWMTimeout = 12; // if 12 periodes long no valid PWM was detected the data are invalid |
| 66 | // 12 * 362 counts * 102.4 us |
66 | // 12 * 362 counts * 102.4 us |
| 67 | } |
- | |
| 68 | else |
- | |
| 69 | { // bad pwm value (out of range or permanent low) |
- | |
| 70 | if(PWMTimeout) PWMTimeout--; // decrement timeout |
- | |
| 71 | CompassHeading = -1; // unknown heading |
- | |
| 72 | CompassOffCourse = 0; |
- | |
| 73 | } |
67 | } |
| 74 | PWMCount = 0; // reset pwm counter |
68 | PWMCount = 0; // reset pwm counter |
| 75 | } |
- | |
| 76 | 69 | } |
|
| 77 | if(!PWMTimeout) |
70 | if(!PWMTimeout) |
| 78 | { |
71 | { |
| 79 | if(CheckDelay(BeepDelay)) |
72 | if(CheckDelay(BeepDelay)) |
| 80 | { |
73 | { |