Subversion Repositories FlightCtrl

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 ingob 1
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2
// + Copyright (c) 04.2007 Holger Buss
1180 killagreg 3
// + Nur für den privaten Gebrauch
1 ingob 4
// + www.MikroKopter.com
5
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1180 killagreg 6
// + Es gilt für das gesamte Projekt (Hardware, Software, Binärfiles, Sourcecode und Dokumentation),
7
// + dass eine Nutzung (auch auszugsweise) nur für den privaten (nicht-kommerziellen) Gebrauch zulässig ist.
8
// + Sollten direkte oder indirekte kommerzielle Absichten verfolgt werden, ist mit uns (info@mikrokopter.de) Kontakt
9
// + bzgl. der Nutzungsbedingungen aufzunehmen.
10
// + Eine kommerzielle Nutzung ist z.B.Verkauf von MikroKoptern, Bestückung und Verkauf von Platinen oder Bausätzen,
11
// + Verkauf von Luftbildaufnahmen, usw.
12
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
13
// + Werden Teile des Quellcodes (mit oder ohne Modifikation) weiterverwendet oder veröffentlicht,
14
// + unterliegen sie auch diesen Nutzungsbedingungen und diese Nutzungsbedingungen incl. Copyright müssen dann beiliegen
15
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
16
// + Sollte die Software (auch auszugesweise) oder sonstige Informationen des MikroKopter-Projekts
17
// + auf anderen Webseiten oder sonstigen Medien veröffentlicht werden, muss unsere Webseite "http://www.mikrokopter.de"
18
// + eindeutig als Ursprung verlinkt werden
19
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
20
// + Keine Gewähr auf Fehlerfreiheit, Vollständigkeit oder Funktion
21
// + Benutzung auf eigene Gefahr
22
// + Wir übernehmen keinerlei Haftung für direkte oder indirekte Personen- oder Sachschäden
23
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
24
// + Die Portierung der Software (oder Teile davon) auf andere Systeme (ausser der Hardware von www.mikrokopter.de) ist nur
25
// + mit unserer Zustimmung zulässig
26
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
27
// + Die Funktion printf_P() unterliegt ihrer eigenen Lizenz und ist hiervon nicht betroffen
28
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
29
// + Redistributions of source code (with or without modifications) must retain the above copyright notice,
30
// + this list of conditions and the following disclaimer.
31
// +   * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived
32
// +     from this software without specific prior written permission.
33
// +   * The use of this project (hardware, software, binary files, sources and documentation) is only permittet
34
// +     for non-commercial use (directly or indirectly)
35
// +     Commercial use (for excample: selling of MikroKopters, selling of PCBs, assembly, ...) is only permitted
36
// +     with our written permission
37
// +   * If sources or documentations are redistributet on other webpages, out webpage (http://www.MikroKopter.de) must be
38
// +     clearly linked as origin
39
// +   * porting to systems other than hardware from www.mikrokopter.de is not allowed
40
// +  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
41
// +  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42
// +  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43
// +  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
44
// +  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
45
// +  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
46
// +  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
47
// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
48
// +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
49
// +  POSSIBILITY OF SUCH DAMAGE.
50
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
886 killagreg 51
#include <stdlib.h>
52
#include <avr/io.h>
53
#include <avr/interrupt.h>
54
 
1 ingob 55
#include "rc.h"
56
#include "main.h"
57
 
886 killagreg 58
volatile int16_t PPM_in[15]; //PPM24 supports 12 channels per frame
59
volatile int16_t PPM_diff[15];
60
volatile uint8_t NewPpmData = 1;
61
volatile int16_t RC_Quality = 0;
1 ingob 62
 
886 killagreg 63
 
64
 
65
/***************************************************************/
66
/*  16bit timer 1 is used to decode the PPM-Signal            */
67
/***************************************************************/
68
void RC_Init (void)
1 ingob 69
{
886 killagreg 70
        uint8_t sreg = SREG;
1 ingob 71
 
886 killagreg 72
        // disable all interrupts before reconfiguration
73
        cli();
74
 
75
        // PPM-signal is connected to the Input Capture Pin (PD6) of timer 1
76
        DDRD &= ~(1<<DDD6);
77
        PORTD |= (1<<PORTD6);
78
 
79
        // Channel 5,6,7 is decoded to servo signals at pin PD5 (J3), PD4(J4), PD3(J5)
80
        // set as output
81
        DDRD |= (1<<DDD5)|(1<<DDD4);
82
        // low level
83
        PORTD &= ~((1<<PORTD5)|(1<<PORTD4));
84
 
1180 killagreg 85
        // PD3 can't be used if 2nd UART is activated
886 killagreg 86
        // because TXD1 is at that port
1180 killagreg 87
        if(CPUType != ATMEGA644P)
886 killagreg 88
        {
89
                DDRD |= (1<<PORTD3);
90
                PORTD &= ~(1<<PORTD3);
91
        }
92
 
93
        // Timer/Counter1 Control Register A, B, C
94
 
95
        // Normal Mode (bits: WGM13=0, WGM12=0, WGM11=0, WGM10=0)
96
        // Compare output pin A & B is disabled (bits: COM1A1=0, COM1A0=0, COM1B1=0, COM1B0=0)
97
        // Set clock source to SYSCLK/64 (bit: CS12=0, CS11=1, CS10=1)
98
        // Enable input capture noise cancler (bit: ICNC1=1)
99
        // Trigger on positive edge of the input capture pin (bit: ICES1=1),
100
        // Therefore the counter incremets at a clock of 20 MHz/64 = 312.5 kHz or 3.2µs
101
    // The longest period is 0xFFFF / 312.5 kHz = 0.209712 s.
102
        TCCR1A &= ~((1<<COM1A1)|(1<<COM1A0)|(1<<COM1B1)|(1<<COM1B0)|(1<<WGM11)|(1<<WGM10));
103
        TCCR1B &= ~((1<<WGM13)|(1<<WGM12)|(1<<CS12));
104
        TCCR1B |= (1<<CS11)|(1<<CS10)|(1<<ICES1)|(1<<ICNC1);
105
        TCCR1C &= ~((1<<FOC1A)|(1<<FOC1B));
106
 
107
        // Timer/Counter1 Interrupt Mask Register
108
 
109
        // Enable Input Capture Interrupt (bit: ICIE1=1)
110
        // Disable Output Compare A & B Match Interrupts (bit: OCIE1B=0, OICIE1A=0)
111
        // Enable Overflow Interrupt (bit: TOIE1=0)
1214 killagreg 112
        TIMSK1 &= ~((1<<OCIE1B)|(1<<OCIE1A)|(1<<TOIE1));
113
    TIMSK1 |= (1<<ICIE1);
886 killagreg 114
 
115
    RC_Quality = 0;
116
 
117
    SREG = sreg;
1 ingob 118
}
119
 
120
 
886 killagreg 121
/********************************************************************/
122
/*         Every time a positive edge is detected at PD6            */
123
/********************************************************************/
124
/*                               t-Frame
125
       <----------------------------------------------------------------------->
126
         ____   ______   _____   ________                ______    sync gap      ____
127
        |    | |      | |     | |        |              |      |                |
128
        |    | |      | |     | |        |              |      |                |
129
     ___|    |_|      |_|     |_|        |_.............|      |________________|
130
        <-----><-------><------><-------->              <------>                <---
131
          t0       t1      t2       t4                     tn                     t0
132
 
133
The PPM-Frame length is 22.5 ms.
134
Channel high pulse width range is 0.7 ms to 1.7 ms completed by an 0.3 ms low pulse.
135
The mininimum time delay of two events coding a channel is ( 0.7 + 0.3) ms = 1 ms.
136
The maximum time delay of two events coding a chanel is ( 1.7 + 0.3) ms = 2 ms.
137
The minimum duration of all channels at minimum value is  8 * 1 ms = 8 ms.
138
The maximum duration of all channels at maximum value is  8 * 2 ms = 16 ms.
139
The remaining time of (22.5 - 8 ms) ms = 14.5 ms  to (22.5 - 16 ms) ms = 6.5 ms is
140
the syncronization gap.
141
*/
142
ISR(TIMER1_CAPT_vect) // typical rate of 1 ms to 2 ms
143
{
144
    int16_t signal = 0, tmp;
145
        static int16_t index;
146
        static uint16_t oldICR1 = 0;
147
 
148
        // 16bit Input Capture Register ICR1 contains the timer value TCNT1
149
        // at the time the edge was detected
150
 
151
        // calculate the time delay to the previous event time which is stored in oldICR1
152
        // calculatiing the difference of the two uint16_t and converting the result to an int16_t
153
        // implicit handles a timer overflow 65535 -> 0 the right way.
154
        signal = (uint16_t) ICR1 - oldICR1;
155
        oldICR1 = ICR1;
156
 
157
    //sync gap? (3.52 ms < signal < 25.6 ms)
158
        if((signal > 1100) && (signal < 8000))
159
        {
160
                // if a sync gap happens and there where at least 4 channels decoded before
161
                // then the NewPpmData flag is reset indicating valid data in the PPM_in[] array.
1214 killagreg 162
                if(index >= 4)
886 killagreg 163
                {
164
                        NewPpmData = 0;  // Null means NewData for the first 4 channels
165
                }
166
                // synchronize channel index
167
                index = 1;
168
        }
169
        else // within the PPM frame
170
    {
171
        if(index < 14) // PPM24 supports 12 channels
1 ingob 172
        {
886 killagreg 173
                        // check for valid signal length (0.8 ms < signal < 2.1984 ms)
174
                        // signal range is from 1.0ms/3.2us = 312 to 2.0ms/3.2us = 625
175
            if((signal > 250) && (signal < 687))
1 ingob 176
            {
886 killagreg 177
                                // shift signal to zero symmetric range  -154 to 159
178
                signal -= 466; // offset of 1.4912 ms ??? (469 * 3.2µs = 1.5008 ms)
179
                // check for stable signal
1214 killagreg 180
                if(abs(signal - PPM_in[index]) < 6)
886 killagreg 181
                {
182
                                        if(RC_Quality < 200) RC_Quality +=10;
1180 killagreg 183
                                        else RC_Quality = 200;
886 killagreg 184
                                }
185
                                // calculate exponential history for signal
186
                tmp = (3 * (PPM_in[index]) + signal) / 4;
604 hbuss 187
                if(tmp > signal+1) tmp--; else
886 killagreg 188
                if(tmp < signal-1) tmp++;
189
                // calculate signal difference on good signal level
190
                if(RC_Quality >= 195)  PPM_diff[index] = ((tmp - PPM_in[index]) / 3) * 3; // cut off lower 3 bit for nois reduction
604 hbuss 191
                else PPM_diff[index] = 0;
886 killagreg 192
                PPM_in[index] = tmp; // update channel value
193
            }
194
            index++; // next channel
195
            // demux sum signal for channels 5 to 7 to J3, J4, J5
1180 killagreg 196
                if(index == 5) J3HIGH; else J3LOW;
197
                if(index == 6) J4HIGH; else J3LOW;
198
                if(CPUType != ATMEGA644P) // not used as TXD1
886 killagreg 199
                {
1180 killagreg 200
                                if(index == 7) J5HIGH; else J5LOW;
886 killagreg 201
                }
1 ingob 202
        }
203
        }
204
}
205
 
206
 
207
 
208
 
209