SSB demodulator arduino DUE

{code}

1. #include <DueTimer.h>
2. #define Ntap 31
3. #define DCgain 32768
4. int myLed = 13;
5. int OutSample,I,Q,N,X1,X2,X3,Y1,Y2,Y3;
6. float count=0;
7. int led_flag=0;
8. int cos_N[4]={1,0,-1,0};
9. int sin_N[4]={0,1,0,-1};
10. int sin_N_m[4]={0,-1,0,1};
11. bool ledOn = false;
12. // Фильтр канала Q
13. int fir_Q(int NewSample) {
14. int FIRCoef[Ntap] = {
15. -406,
16. -207,
17. 529,
18. 240,
19. -698,
20. -274,
21. 942,
22. 308,
23. -1317,
24. -338,
25. 1972,
26. 363,
27. -3441,
28. -379,
29. 10572,
30. 17042,
31. 10572,
32. -379,
33. -3441,
34. 363,
35. 1972,
36. -338,
37. -1317,
38. 308,
39. 942,
40. -274,
41. -698,
42. 240,
43. 529,
44. -207,
45. -406
46. };
47. static int x[Ntap]; //input samples
48. long int y=0; //output sample
49. int n;
50. //shift the old samples
51. for(n=Ntap-1; n>0; n--)
52. x[n] = x[n-1];
53. //Calculate the new output
54. x[0] = NewSample;
55. for(n=0; n<Ntap; n++)
56. y += FIRCoef[n] * x[n];
58. return y / DCgain;
60. }
61. // Фильтр канала I
62. int fir_I(int NewSample) {
63. int FIRCoef[Ntap] = {
64. -406,
65. -207,
66. 529,
67. 240,
68. -698,
69. -274,
70. 942,
71. 308,
72. -1317,
73. -338,
74. 1972,
75. 363,
76. -3441,
77. -379,
78. 10572,
79. 17042,
80. 10572,
81. -379,
82. -3441,
83. 363,
84. 1972,
85. -338,
86. -1317,
87. 308,
88. 942,
89. -274,
90. -698,
91. 240,
92. 529,
93. -207,
94. -406
95. };
96. static int x[Ntap]; //input samples
97. long int y=0; //output sample
98. int n;
99. //shift the old samples
100. for(n=Ntap-1; n>0; n--)
101. x[n] = x[n-1];
102. //Calculate the new output
103. x[0] = NewSample;
104. for(n=0; n<Ntap; n++)
105. y += FIRCoef[n] * x[n];
107. return y / DCgain;
109. }
110. void myHandler(){ // обработчик прерывания по таймеру
111. if (N==3)
112. {
113. N=0;
114. }
115. else N++;
116. I=analogRead(A0);
117. Q=analogRead(A1);
118. X1=I*cos_N[N]+Q*sin_N[N];
119. X2=fir_I(X1);
120. X3=X2*cos_N[N];
121. Y1=I*sin_N_m[N]+Q*cos_N[N];
122. Y2=fir_Q(Y1);
123. Y3=Y2*sin_N_m[N];
124. OutSample=X3+Y3;
125. OutSample=OutSample+512;// восстанавливаем однополярный сигнал
126. analogWrite(DAC0, OutSample);
127. }
129. void setup(){
130. pinMode(myLed, OUTPUT);
131. Timer3.attachInterrupt(myHandler);
132. Timer3.start(1000000); // Calls every 50ms
133. pinMode(DAC0, OUTPUT);
134. pinMode(A0, INPUT);
135. pinMode(A1, INPUT);
136. }
137. void loop(){
138. while(1){
139. // I'm stuck in here! help me...
140. }

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