WebSVN - FlightCtrl - Diff - Rev 689 and 690 - /branches/V0.68d Code Redesign killagreg/rc.c


/*#######################################################################################
Decodieren eines RC Summen Signals
#######################################################################################*/
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// + Copyright (c) 04.2007 Holger Buss
// + only for non-profit use
// + www.MikroKopter.com
// + see the File "License.txt" for further Informations
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
#include <stdlib.h>
#include <avr/io.h>
#include <avr/interrupt.h>
 
#include "rc.h"
 
 
volatile int16_t PPM_in[11];
volatile int16_t PPM_diff[11];
volatile uint8_t NewPpmData = 1;
volatile uint8_t SenderOkay = 0;
 
/***************************************************************/
/*  16bit timer 1 is used to decode the PPM-Signal            */
/***************************************************************/
void rc_sum_init (void)
{
        uint8_t sreg = SREG;
 
        // disable all interrupts before reconfiguration
        cli();
 
        // PPM-signal is connected to the Input Capture Pin (PD6) of timer 1
        DDRD &= ~(1<<DDD6);
        PORTD |= (1<<PORTD6);
 
        // Channel 5,6,7 is decoded to servo signals at pin PD5 (J3), PD4(J4), PD3(J5)
        // set as output
        DDRD |= (1<<DDD5)|(1<<DDD4)|(1<<DDD3);
        // low level
        PORTD &= ~((1<<PORTD5)|(1<<PORTD4)|(1<<PORTD3));
 
        // Timer/Counter1 Control Register A, B, C
 
        // Normal Mode (bits: WGM13=0, WGM12=0, WGM11=0, WGM10=0)
        // Compare output pin A & B is disabled (bits: COM1A1=0, COM1A0=0, COM1B1=0, COM1B0=0)
        // Set clock source to SYSCLK/64 (bit: CS12=0, CS11=1, CS10=1)
        // Enable input capture noise cancler (bit: ICNC1=1)
        // Trigger on positive edge of the input capture pin (bit: ICES1=1),
        // Therefore the counter incremets at a clock of 20 MHz/64 = 312.5 kHz or 3.2µs
    // The longest period is 0xFFFF / 312.5 kHz = 0.209712 s.
        TCCR1A &= ~((1<<COM1A1)|(1<<COM1A0)|(1<<COM1B1)|(1<<COM1B0)|(1<<WGM11)|(1<<WGM10));
        TCCR1B &= ~((1<<WGM13)|(1<<WGM12)|(1<<CS12));
        TCCR1B |= (1<<CS11)|(1<<CS10)|(1<<ICES1)|(1<<ICNC1);
        TCCR1C &= ~((1<<FOC1A)|(1<<FOC1B));
 
        // Timer/Counter1 Interrupt Mask Register
 
        // Enable Input Capture Interrupt (bit: ICIE1=1)
        // Disable Output Compare A & B Match Interrupts (bit: OCIE1B=0, OICIE1A=0)
        // Disable Overflow Interrupt (bit: TOIE1=0)
        TIMSK1 &= ~((1<<OCIE1B)|(1<<OCIE1A)|(1<<TOIE1));
    TIMSK1 |= (1<<ICIE1);
 
 
 
 
 
    SREG = sreg;
}
 
 
/********************************************************************/
/*         Every time a positive edge is detected at PD6            */
/********************************************************************/
/*
The PPM-Frame length is 22.5 ms.
Channel high pulse width range is 0.7 ms to 1.7 ms completed by an 0.3 ms low pulse.
The mininimum time delay of two events coding a channel is ( 0.7 + 0.3) ms = 1 ms.
The maximum time delay of two events coding a chanel is ( 1.7 + 0.3) ms = 2 ms.
The minimum duration of all channels at minimum value is  8 * 1 ms = 8 ms.
The maximum duration of all channels at maximum value is  8 * 2 ms = 16 ms.
The remaining time of (22.5 - 8 ms) ms = 14.5 ms  to (22.5 - 16 ms) ms = 6.5 ms is
the syncronization gap.
*/
ISR(TIMER1_CAPT_vect) // typical rate of 1 ms to 2 ms
{
        static uint16_t oldICR1 = 0;
    int16_t signal = 0, tmp;
        static int16_t index;
 
        // 16bit Input Capture Register ICR1 contains the timer value TCNT1
        // at the time the edge was detected
 
        // calculate the time delay to the previous event time which is stored in oldICR1
        signal = (uint16_t) ICR1 - oldICR1;
        oldICR1 = ICR1;
 
 
    //sync gap? (3.52 ms < signal < 25.6 ms)
        if((signal > 1100) && (signal < 8000))
        {
                // if a sync gap happens and there where at least 4 channels decoded before
                // then the NewPpmData flag is reset indicating valid data in the PPM_in[] array.
                if(index >= 4)  NewPpmData = 0;  // Null means NewData
                // synchronize channel index
                index = 1;
        }
        else // within the PPM frame
        {
        if(index < 10) // channel limit is 9 because of the frame length of 22.5 ms
        {
                        // check for valid signal length (0.8 ms < signal < 2.1984 ms)
            if((signal > 250) && (signal < 687))
            {
                signal -= 466; // offset of 1.4912 ms ??? (469 * 3.2µs = 1.5008 ms)
                // check for stable signal
                // the deviation of the current signal level from the average must be less than 6 (aprox. 1%)
                if(abs(signal - PPM_in[index]) < 6)
                {
                                        // a good signal condition increases SenderOkay by 10
                                        // SignalOkay is decremented every 2 ms in timer0.c
                                        // this variable is a level for the average rate of noiseless signal
                                        if(SenderOkay < 200) SenderOkay += 10;
                                }
                                // calculate exponential history for signal
                tmp = (3 * (PPM_in[index]) + signal) / 4;
                if(tmp > signal+1) tmp--; else
                if(tmp < signal-1) tmp++;
                // calculate signal difference on good signal level
                if(SenderOkay >= 195)  PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for nois reduction
                else PPM_diff[index] = 0;
                PPM_in[index] = tmp; // update channel value
            }
            index++; // next channel
            // demux sum signal for channels 5 to 7 to J3, J4, J5
                if(index == 5) PORTD |= (1<<PORTD5); else PORTD &= ~(1<<PORTD5);
                if(index == 6) PORTD |= (1<<PORTD4); else PORTD &= ~(1<<PORTD4);
                if(index == 7) PORTD |= (1<<PORTD3); else PORTD &= ~(1<<PORTD3);
        }
        }
}
 
 
 
 
 
 

Subversion Repositories FlightCtrl

(root)/branches/V0.68d Code Redesign killagreg/rc.c - Rev 689 → 690

Rev 689		Rev 690
1	/*#######################################################################################	1	/*#######################################################################################
2	Decodieren eines RC Summen Signals	2	Decodieren eines RC Summen Signals
3	#######################################################################################*/	3	#######################################################################################*/
4	// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++	4	// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
5	// + Copyright (c) 04.2007 Holger Buss	5	// + Copyright (c) 04.2007 Holger Buss
6	// + only for non-profit use	6	// + only for non-profit use
7	// + www.MikroKopter.com	7	// + www.MikroKopter.com
8	// + see the File "License.txt" for further Informations	8	// + see the File "License.txt" for further Informations
9	// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++	9	// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
10		10
11	#include <stdlib.h>	11	#include <stdlib.h>
12	#include <avr/io.h>	12	#include <avr/io.h>
13	#include <avr/interrupt.h>	13	#include <avr/interrupt.h>
14		14
15	#include "rc.h"	15	#include "rc.h"
16	#include "fc.h"	-
17		16
18	volatile int16_t PPM_in[11];	17	volatile int16_t PPM_in[11];
19	volatile int16_t PPM_diff[11];	18	volatile int16_t PPM_diff[11];
20	volatile uint8_t NewPpmData = 1;	19	volatile uint8_t NewPpmData = 1;
21	volatile uint8_t SenderOkay = 0;	20	volatile uint8_t SenderOkay = 0;
22		21
23	/***************************************************************/	22	/***************************************************************/
24	/* 16bit timer 1 is used to decode the PPM-Signal */	23	/* 16bit timer 1 is used to decode the PPM-Signal */
25	/***************************************************************/	24	/***************************************************************/
26	void rc_sum_init (void)	25	void rc_sum_init (void)
27	{	26	{
28	uint8_t sreg = SREG;	27	uint8_t sreg = SREG;
29		28
30	// disable all interrupts before reconfiguration	29	// disable all interrupts before reconfiguration
31	cli();	30	cli();
32		31
33	// PPM-signal is connected to the Input Capture Pin (PD6) of timer 1	32	// PPM-signal is connected to the Input Capture Pin (PD6) of timer 1
34	DDRD &= ~(1<<DDD6);	33	DDRD &= ~(1<<DDD6);
35	PORTD \|= (1<<PORTD6);	34	PORTD \|= (1<<PORTD6);
36		35
37	// Channel 5,6,7 is decoded to servo signals at pin PD5 (J3), PD4(J4), PD3(J5)	36	// Channel 5,6,7 is decoded to servo signals at pin PD5 (J3), PD4(J4), PD3(J5)
38	// set as output	37	// set as output
39	DDRD \|= (1<<DDD5)\|(1<<DDD4)\|(1<<DDD3);	38	DDRD \|= (1<<DDD5)\|(1<<DDD4)\|(1<<DDD3);
40	// low level	39	// low level
41	PORTD &= ~((1<<PORTD5)\|(1<<PORTD4)\|(1<<PORTD3));	40	PORTD &= ~((1<<PORTD5)\|(1<<PORTD4)\|(1<<PORTD3));
42		41
43	// Timer/Counter1 Control Register A, B, C	42	// Timer/Counter1 Control Register A, B, C
44		43
45	// Normal Mode (bits: WGM13=0, WGM12=0, WGM11=0, WGM10=0)	44	// Normal Mode (bits: WGM13=0, WGM12=0, WGM11=0, WGM10=0)
46	// Compare output pin A & B is disabled (bits: COM1A1=0, COM1A0=0, COM1B1=0, COM1B0=0)	45	// Compare output pin A & B is disabled (bits: COM1A1=0, COM1A0=0, COM1B1=0, COM1B0=0)
47	// Set clock source to SYSCLK/64 (bit: CS12=0, CS11=1, CS10=1)	46	// Set clock source to SYSCLK/64 (bit: CS12=0, CS11=1, CS10=1)
48	// Enable input capture noise cancler (bit: ICNC1=1)	47	// Enable input capture noise cancler (bit: ICNC1=1)
49	// Trigger on positive edge of the input capture pin (bit: ICES1=1),	48	// Trigger on positive edge of the input capture pin (bit: ICES1=1),
50	// Therefore the counter incremets at a clock of 20 MHz/64 = 312.5 kHz or 3.2µs	49	// Therefore the counter incremets at a clock of 20 MHz/64 = 312.5 kHz or 3.2µs
51	// The longest period is 0xFFFF / 312.5 kHz = 0.209712 s.	50	// The longest period is 0xFFFF / 312.5 kHz = 0.209712 s.
52	TCCR1A &= ~((1<<COM1A1)\|(1<<COM1A0)\|(1<<COM1B1)\|(1<<COM1B0)\|(1<<WGM11)\|(1<<WGM10));	51	TCCR1A &= ~((1<<COM1A1)\|(1<<COM1A0)\|(1<<COM1B1)\|(1<<COM1B0)\|(1<<WGM11)\|(1<<WGM10));
53	TCCR1B &= ~((1<<WGM13)\|(1<<WGM12)\|(1<<CS12));	52	TCCR1B &= ~((1<<WGM13)\|(1<<WGM12)\|(1<<CS12));
54	TCCR1B \|= (1<<CS11)\|(1<<CS10)\|(1<<ICES1)\|(1<<ICNC1);	53	TCCR1B \|= (1<<CS11)\|(1<<CS10)\|(1<<ICES1)\|(1<<ICNC1);
55	TCCR1C &= ~((1<<FOC1A)\|(1<<FOC1B));	54	TCCR1C &= ~((1<<FOC1A)\|(1<<FOC1B));
56		55
57	// Timer/Counter1 Interrupt Mask Register	56	// Timer/Counter1 Interrupt Mask Register
58		57
59	// Enable Input Capture Interrupt (bit: ICIE1=1)	58	// Enable Input Capture Interrupt (bit: ICIE1=1)
60	// Disable Output Compare A & B Match Interrupts (bit: OCIE1B=0, OICIE1A=0)	59	// Disable Output Compare A & B Match Interrupts (bit: OCIE1B=0, OICIE1A=0)
61	// Disable Overflow Interrupt (bit: TOIE1=0)	60	// Disable Overflow Interrupt (bit: TOIE1=0)
62	TIMSK1 &= ~((1<<OCIE1B)\|(1<<OCIE1A)\|(1<<TOIE1));	61	TIMSK1 &= ~((1<<OCIE1B)\|(1<<OCIE1A)\|(1<<TOIE1));
63	TIMSK1 \|= (1<<ICIE1);	62	TIMSK1 \|= (1<<ICIE1);
64		-
65	AdNeutralGier = 0;	-
66	AdNeutralRoll = 0;	-
67	AdNeutralNick = 0;	-
68		63
69	SREG = sreg;	64	SREG = sreg;
70	}	65	}
71		66
72		67
73	/********************************************************************/	68	/********************************************************************/
74	/* Every time a positive edge is detected at PD6 */	69	/* Every time a positive edge is detected at PD6 */
75	/********************************************************************/	70	/********************************************************************/
76	/*	71	/*
77	The PPM-Frame length is 22.5 ms.	72	The PPM-Frame length is 22.5 ms.
78	Channel high pulse width range is 0.7 ms to 1.7 ms completed by an 0.3 ms low pulse.	73	Channel high pulse width range is 0.7 ms to 1.7 ms completed by an 0.3 ms low pulse.
79	The mininimum time delay of two events coding a channel is ( 0.7 + 0.3) ms = 1 ms.	74	The mininimum time delay of two events coding a channel is ( 0.7 + 0.3) ms = 1 ms.
80	The maximum time delay of two events coding a chanel is ( 1.7 + 0.3) ms = 2 ms.	75	The maximum time delay of two events coding a chanel is ( 1.7 + 0.3) ms = 2 ms.
81	The minimum duration of all channels at minimum value is 8 * 1 ms = 8 ms.	76	The minimum duration of all channels at minimum value is 8 * 1 ms = 8 ms.
82	The maximum duration of all channels at maximum value is 8 * 2 ms = 16 ms.	77	The maximum duration of all channels at maximum value is 8 * 2 ms = 16 ms.
83	The remaining time of (22.5 - 8 ms) ms = 14.5 ms to (22.5 - 16 ms) ms = 6.5 ms is	78	The remaining time of (22.5 - 8 ms) ms = 14.5 ms to (22.5 - 16 ms) ms = 6.5 ms is
84	the syncronization gap.	79	the syncronization gap.
85	*/	80	*/
86	ISR(TIMER1_CAPT_vect) // typical rate of 1 ms to 2 ms	81	ISR(TIMER1_CAPT_vect) // typical rate of 1 ms to 2 ms
87	{	82	{
88	static uint16_t oldICR1 = 0;	83	static uint16_t oldICR1 = 0;
89	int16_t signal = 0, tmp;	84	int16_t signal = 0, tmp;
90	static int16_t index;	85	static int16_t index;
91		86
92	// 16bit Input Capture Register ICR1 contains the timer value TCNT1	87	// 16bit Input Capture Register ICR1 contains the timer value TCNT1
93	// at the time the edge was detected	88	// at the time the edge was detected
94		89
95	// calculate the time delay to the previous event time which is stored in oldICR1	90	// calculate the time delay to the previous event time which is stored in oldICR1
96	signal = (uint16_t) ICR1 - oldICR1;	91	signal = (uint16_t) ICR1 - oldICR1;
97	oldICR1 = ICR1;	92	oldICR1 = ICR1;
98		93
99		94
100	//sync gap? (3.52 ms < signal < 25.6 ms)	95	//sync gap? (3.52 ms < signal < 25.6 ms)
101	if((signal > 1100) && (signal < 8000))	96	if((signal > 1100) && (signal < 8000))
102	{	97	{
103	// if a sync gap happens and there where at least 4 channels decoded before	98	// if a sync gap happens and there where at least 4 channels decoded before
104	// then the NewPpmData flag is reset indicating valid data in the PPM_in[] array.	99	// then the NewPpmData flag is reset indicating valid data in the PPM_in[] array.
105	if(index >= 4) NewPpmData = 0; // Null means NewData	100	if(index >= 4) NewPpmData = 0; // Null means NewData
106	// synchronize channel index	101	// synchronize channel index
107	index = 1;	102	index = 1;
108	}	103	}
109	else // within the PPM frame	104	else // within the PPM frame
110	{	105	{
111	if(index < 10) // channel limit is 9 because of the frame length of 22.5 ms	106	if(index < 10) // channel limit is 9 because of the frame length of 22.5 ms
112	{	107	{
113	// check for valid signal length (0.8 ms < signal < 2.1984 ms)	108	// check for valid signal length (0.8 ms < signal < 2.1984 ms)
114	if((signal > 250) && (signal < 687))	109	if((signal > 250) && (signal < 687))
115	{	110	{
116	signal -= 466; // offset of 1.4912 ms ??? (469 * 3.2µs = 1.5008 ms)	111	signal -= 466; // offset of 1.4912 ms ??? (469 * 3.2µs = 1.5008 ms)
117	// check for stable signal	112	// check for stable signal
118	// the deviation of the current signal level from the average must be less than 6 (aprox. 1%)	113	// the deviation of the current signal level from the average must be less than 6 (aprox. 1%)
119	if(abs(signal - PPM_in[index]) < 6)	114	if(abs(signal - PPM_in[index]) < 6)
120	{	115	{
121	// a good signal condition increases SenderOkay by 10	116	// a good signal condition increases SenderOkay by 10
122	// SignalOkay is decremented every 2 ms in timer0.c	117	// SignalOkay is decremented every 2 ms in timer0.c
123	// this variable is a level for the average rate of noiseless signal	118	// this variable is a level for the average rate of noiseless signal
124	if(SenderOkay < 200) SenderOkay += 10;	119	if(SenderOkay < 200) SenderOkay += 10;
125	}	120	}
126	// calculate exponential history for signal	121	// calculate exponential history for signal
127	tmp = (3 * (PPM_in[index]) + signal) / 4;	122	tmp = (3 * (PPM_in[index]) + signal) / 4;
128	if(tmp > signal+1) tmp--; else	123	if(tmp > signal+1) tmp--; else
129	if(tmp < signal-1) tmp++;	124	if(tmp < signal-1) tmp++;
130	// calculate signal difference on good signal level	125	// calculate signal difference on good signal level
131	if(SenderOkay >= 195) PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for nois reduction	126	if(SenderOkay >= 195) PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for nois reduction
132	else PPM_diff[index] = 0;	127	else PPM_diff[index] = 0;
133	PPM_in[index] = tmp; // update channel value	128	PPM_in[index] = tmp; // update channel value
134	}	129	}
135	index++; // next channel	130	index++; // next channel
136	// demux sum signal for channels 5 to 7 to J3, J4, J5	131	// demux sum signal for channels 5 to 7 to J3, J4, J5
137	if(index == 5) PORTD \|= (1<<PORTD5); else PORTD &= ~(1<<PORTD5);	132	if(index == 5) PORTD \|= (1<<PORTD5); else PORTD &= ~(1<<PORTD5);
138	if(index == 6) PORTD \|= (1<<PORTD4); else PORTD &= ~(1<<PORTD4);	133	if(index == 6) PORTD \|= (1<<PORTD4); else PORTD &= ~(1<<PORTD4);
139	if(index == 7) PORTD \|= (1<<PORTD3); else PORTD &= ~(1<<PORTD3);	134	if(index == 7) PORTD \|= (1<<PORTD3); else PORTD &= ~(1<<PORTD3);
140	}	135	}
141	}	136	}
142	}	137	}
143		138
144		139
145		140
146		141
147		142
148		143