PIC Sound Generator

Discussion in 'Embedded Systems and Microcontrollers' started by ELECTRONERD, Aug 10, 2010.

1. ELECTRONERD Thread Starter Senior Member

May 26, 2009
1,146
16
Hey Everyone,

I haven't been on AAC for a little while, my job has kept me busy. I still browse the other posts when I can, and I try to remain assiduous at my projects after I finish work each day, if time permits of course.

Project:

I just began programming with PICs and have run through a series of projects to exercise my skill level in programming; this particular project is entitled a "PIC Sound Generator" in which it will generate notes at my command.

Theory & Operation:

I begin with all my header files, definings, etc. until I reach my first function. This function allows me to enter a note that I previously stored into an array, and then define how long of a duration I wish it to play for.

My frequency is set by Timer0 on the PIC, in which I rapidly turn RA0 on and off depending on my TMR0L and TMR0H values, and furthermore, my array value. TMR0H and TMR0L enable me to use 16-bit mode since my lowest note is 1515μS. Remember that I wish to know my lowest frequency note since the delay is longer. If I were to use 8-bit, my maximum delay would be 128μS. Thus, equation for 16-Bit timer:

$Frequency Delay = [(65536 - Delay)*0.5uS]2$

Which simplifies to:

$Frequency Delay (uS) = (65536 - Delay)$

It has already been noted to me that Timer2 would be a better choice, but I wish to become more familliar with all the PICs abilities and attributes, so I will eventually learn about Timer2 as well.

In the main() function, you see I have a long list of the playNote function commands. These, as I mentioned, give me what note I want and for how long I wish to play it. The latter statement is based on whole notes (actually quarter notes) and half notes (actually eighth notes). The music is depicted here:

The time signature is 3/4; meaning there are 3 quarter (1/4) notes per measure; or section in my comments. Therefore, to make the music even, a section must eventually add up to 3 quarter notes. Otherwise, the music becomes convoluted and not very pleasant to listen to. I can, at my disposal, change how fast I want my music to play if I change my WHOLE or HALF values previously defined at the beginning. Note that they correlate with one another; if I have 800 as the WHOLE, I must have half of that for the HALF value. I was fortunate to have experience in this regard (I play classical guitar), so that made things much easier.

Code:
• Using PIC18F1320, with C18 compiler
Code ( (Unknown Language)):
1. //
2. // CreatingSound2.C Song "God Save The Queen"
3. //
4.  #include <p18f1320.h>
5.  #include <delays.h>
6.  #include <stdlib.h>
7.  #pragma config OSC=INTIO2, WDT=OFF, LVP=OFF, DEBUG=ON
8.  #define PAUSE Delay1KTCYx(50);
9.  #define WHOLE 1000
10.  #define HALF 500
11.  #define LONG 2000
12.
13. void playNote(unsigned int note, unsigned int timer)   // Note & Timer driver; determines which note will be played and for how long
14.         {
15.     unsigned int times, freq, notes[] = {64021, 64105, 64185, 64260, 64331, 64398, 64462, 64522, 64578, 64632, 64682, 64730, 64774, 64817, 64856, 64895};
16.                 freq = notes[note];   // Determine frequency based on array value
17.                 INTCONbits.TMR0IF = 0;   // Clear OVF Flag
18.                 LATA = 0x01;   // Initialize LATA
19.                 TMR0L = freq & 0xFF;
20.                 TMR0H = (freq >> 8) & 0xFF;
21.                 T0CON|=0x80;
22.
23.                 for(times=timer;times>0;times--)   // Duration of playing
24.                 {
25.                                 TMR0H = (freq >> 8) & 0xFF;   //Load TMR0H byte first
26.                                 TMR0L = freq & 0xFF;   // Load TMR0L byte next
27.                                 while(!INTCONbits.TMR0IF);   // Wait for timer
28. `        INTCONbits.TMR0IF = 0;   // Clear OVF Flag
29.         LATA = ~LATA;   // Invert output
30.                 }
31.    PAUSE;
32.         }
33.
34.  void main()
35.  {
36.
37.  OSCCONbits.IRCF0=1;
38.  OSCCONbits.IRCF1=1;
39.  OSCCONbits.IRCF2=1;
40.  T0CONbits.TMR0ON = 0;   // Don't turn timer on yet
41.  T0CONbits.T08BIT = 0;  // Timer0 is configured as 16-bit timer
42.  T0CONbits.T0CS = 0;   // Use internal clock
43.  T0CONbits.PSA = 1;   // Prescaler is not assigned
44.  T0CONbits.T0PS2 = 0;
45.  T0CONbits.T0PS1 = 0;
46.  T0CONbits.T0PS0 = 0;
47.  while(!OSCCONbits.IOFS);
48.  TRISA = 0b11111110;   // Use RA0 as output
49.
50.  while(1)
51.  {
52.   playNote(3, WHOLE);  // Section 1
53.   playNote(3, WHOLE);
54.   playNote(3, WHOLE);
55.
56.   playNote(1, WHOLE);  // Section 2
57.   playNote(3, HALF);
58.   playNote(5, WHOLE);
59.
60.   playNote(7, WHOLE);  // Section 3
61.   playNote(7, WHOLE);
62.   playNote(8, WHOLE);
63.
64.   playNote(5, WHOLE);  // Section 4
65.   playNote(7, HALF);
66.   playNote(8, WHOLE);
67.
68.   playNote(12, WHOLE); // Section 5
69.   playNote(0, WHOLE);
70.   playNote(12, WHOLE);
71.
72.   playNote(7, WHOLE);  // Section 6
73.   playNote(8, HALF);
74.   playNote(10, WHOLE);
75.
76.   playNote(12, WHOLE); // Section 7
77.   playNote(12, WHOLE);
78.   playNote(13, WHOLE);
79.
80.   playNote(10, WHOLE); // Section 8
81.   playNote(10, HALF);
82.   playNote(12, WHOLE);
83.
84.   playNote(5, WHOLE);  // Section 9
85.   playNote(1, WHOLE);
86.   playNote(3, HALF);
87.
88.   playNote(3, LONG);  // Section 10
89.
90.   playNote(10, WHOLE); // Section 11
91.   playNote(10, WHOLE);
92.   playNote(10, WHOLE);
93.
94.   playNote(10, WHOLE); // Section 12
95.   playNote(8, HALF);
96.   playNote(7, WHOLE);
97.
98.   playNote(8, WHOLE);  // Section 13
99.   playNote(8, WHOLE);
100.   playNote(8, WHOLE);
101.
102.   playNote(8, WHOLE);  // Section 14
103.   playNote(7, HALF);
104.   playNote(5, WHOLE);
105.
106.   playNote(5, WHOLE);  // Section 15
107.   playNote(7, WHOLE);
108.   playNote(7, HALF);
109.
110.   playNote(0, LONG);  // Section 16
111.
112.   playNote(15, WHOLE); // Section 17
113.   playNote(15, WHOLE);
114.   playNote(15, WHOLE);
115.
116.   playNote(15, WHOLE); // Section 18
117.   playNote(13, HALF);
118.   playNote(12, WHOLE);
119.
120.   playNote(13, WHOLE); // Section 19
121.   playNote(13, WHOLE);
122.   playNote(13, WHOLE);
123.
124.   playNote(13, WHOLE); // Section 20
125.   playNote(12, HALF);
126.   playNote(10, WHOLE);
127.
128.   playNote(7, WHOLE);  // Section 21
129.   playNote(8, HALF);
130.   playNote(7, HALF);
131.   playNote(5, HALF);
132.   playNote(3, HALF);
133.
134.   playNote(7, WHOLE);  // Section 22
135.   playNote(8, HALF);
136.   playNote(10, WHOLE);
137.
138.   playNote(12, WHOLE); // Section 23
139.   playNote(5, WHOLE);
140.   playNote(3, HALF);
141.
142.   playNote(3, LONG);  // Section 24
143.
144.   playNote(12, WHOLE); // Section 25
145.   playNote(13, HALF);
146.   playNote(12, HALF);
147.   playNote(10, HALF);
148.   playNote(8, HALF);
149.
150.   playNote(7, WHOLE);  // Section 26
151.   playNote(5, HALF);
152.   playNote(3, WHOLE);
153.
154.   playNote(5, WHOLE);  // Section 27
155.   playNote(7, WHOLE);
156.   playNote(7, HALF);
157.
158.   playNote(0, LONG);  // Section 28
159.
160.   Delay100TCYx(255);
161.  }
162. }

A picture of my setup is depicted in the attachements and to see it working click the following link:

On the o'scope you'll notice that the waveform is somewhat distorted, this is due to the speaker. If I were to take that off, not only would you not have any sound (obviously), but it would then give you an adequate square wave.

I hope you all enjoyed this! If you have any suggestions or comments for me, please feel free to mention them! I would be grateful for any comments in order to edify myself.

I would like to thank 3v0 and Hayato for their help!

Austin

File size:
281.8 KB
Views:
67
• PICSoundGenerator 002.jpg
File size:
276.5 KB
Views:
49
Last edited: Aug 10, 2010

Jan 11, 2009
821
49

3. ELECTRONERD Thread Starter Senior Member

May 26, 2009
1,146
16
I apologize, I suppose this particular thread should have been moved to the Projects forum! It is a completed project I recently did, so I thought I would share it with everyone.

Sorry for the misunderstanding!

Thanks,

Austin

4. retched AAC Fanatic!

Dec 5, 2009
5,201
315
The ability to read an external file, possibly from a memory card, to enable you to compose separate 'songs' without needing separate PICs to play them would be a nice next logical step.

This is a nice project for folks who wish to get involved in PIC programming and in-circuit programming.

It gives instant feedback of a job-well-done.

Good Job.

5. ELECTRONERD Thread Starter Senior Member

May 26, 2009
1,146
16
Thanks Retched!

Now I'm storing additional songs into 2D arrays, containing the notes and time values. I plan on having three switches which will enable me to select between the three different songs. I'll post the results here when I finish!

Apr 5, 2008
16,965
2,960
Hello,

When you made the changes, can you also post the schematic?
Then it would be a complete project.

Bertus

7. ELECTRONERD Thread Starter Senior Member

May 26, 2009
1,146
16
Hi Bertus,

It really isn't much of a schematic, simply a 47μF cap connected from the RA0 I/O pin and then to the speaker.

If you think it is necessary, I can make a schematic.

8. retched AAC Fanatic!

Dec 5, 2009
5,201
315
Might as well post the schematic. Im sure this will be a popular project with first time uC users. At least that way they have a schematic to compare their build against, no matter how simple or small.

9. ELECTRONERD Thread Starter Senior Member

May 26, 2009
1,146
16
Alright, then I'll go ahead and post it for everyone. However, this project is a progressional type of one, thus I am currently working on it with several more features. I'll post both the schematics when I finish.

Till Then,

Austin

10. ELECTRONERD Thread Starter Senior Member

May 26, 2009
1,146
16
Hey Everyone,

Here is the schematic, as requested in addition to the new code:

http://mufnet.net/index.php?show=1261

Code ( (Unknown Language)):
1. [FONT=monospace]
2. [LIST=1]
3. [*]//
4. [*]//      CreatingSound3.C
5. [*]//
6. [*]        #include <p18f1320.h>
7. [*]        #include <delays.h>
9. [*]        #pragma config OSC=INTIO2, WDT=OFF, LVP=OFF, DEBUG=ON
10. [*]        #define PAUSE Delay1KTCYx(50);
11. [*]        rom const unsigned int songs[6][80] = {
12. [*]                                                                {0, 5, 7, 8, 10, 8, 0, 0, 5, 7, 8, 0, 8, 5, 12, 10, 12, 17, 19, 20, 22, 20, 12, 12, 17, 19, 20, 12, 20, 17, 24, 22, 12, 12, 17, 19, 20, 17, 24, 20, 29, 17, 17, 20, 19, 17, 24, 20, 17, 12, 12, 17, 30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
13. [*]                                                                {500, 1000, 1500, 250, 250, 1000, 500, 500, 1500, 250, 250, 250, 250, 250, 250, 1500, 500, 1000, 1500, 250, 250, 1000, 500, 500, 1500, 250, 250, 250, 250, 250, 250, 1500, 250, 250, 500, 250, 250, 250, 250, 250, 1000, 250, 250, 250, 250, 250, 1500, 250, 250, 500, 500, 1500, 500, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
14. [*]                                                                {7, 9, 10, 9, 10, 12, 14, 15, 14, 12, 10, 14, 15, 14, 19, 17, 19, 12, 14, 15, 14, 30, 10, 12, 14, 12, 10, 14, 9, 10, 9, 9, 10, 12, 10, 9, 7, 9, 7, 6, 10, 9, 10, 9, 7, 6, 14, 7, 12, 10, 9, 14, 15, 17, 15, 14, 12, 9, 7, 6, 7, 30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
15. [*]                                                                {500, 500, 500, 250, 500, 500, 500, 500, 500, 250, 500, 500, 500, 500, 500, 250, 500, 500, 500, 500, 1500, 500, 500, 500, 500, 250, 500, 1500, 500, 250, 500, 500, 500, 500, 500, 250, 500, 500, 500, 500, 1000, 500, 500, 250, 500, 1000, 500, 500, 250, 500, 1500, 500, 250, 500, 500, 250, 500, 1500, 250, 500, 1500, 5000, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
16. [*]                                                                {5, 5, 5, 3, 5, 7, 9, 9, 10, 7, 9, 10, 14, 2, 14, 9, 10, 12, 14, 14, 158, 12, 12, 14, 7, 3, 5, 5, 12, 12, 12, 12, 10, 9, 10, 10, 10, 10, 9, 7, 7, 9, 9, 2, 17, 17, 17, 17, 15, 14, 15, 15, 15, 15, 14, 12, 9, 10, 9, 7, 5, 9, 10, 12, 14, 7, 5, 5, 14, 15, 14, 12, 10, 9, 7, 5, 7, 9, 9, 20},
17. [*]                                                                {500, 500, 500, 1500, 250, 500, 500, 500, 500, 1500, 250, 500, 500, 500, 500, 1500, 250, 500, 500, 500, 500, 1500, 250, 500, 500, 1000, 250, 1500, 500, 500, 500, 1500, 250, 500, 500, 500, 500, 1500, 250, 500, 500, 500, 250, 1500, 500, 500, 500, 1500, 250, 500, 500, 500, 500, 1500, 250, 500, 500, 250, 250, 250, 250, 1500, 250, 500, 500, 1500, 250, 1500, 500, 250, 250, 250, 250, 1500, 250, 500, 500, 1500, 250, 1500}
18. [*]                                                          };
19. [*]void playNote(unsigned int note, unsigned int timer)   // Note & Timer driver; determines which note will be played and for how long
20. [*]        {
21. [*]                        unsigned int times, freq, notes[] = {58725, 59107, 59468, 59809, 60131, 60434, 60720, 60990, 61245, 61486, 61714, 61928, 62131, 62322, 62502, 62672, 62833, 62985, 63128, 63263, 63391, 63511, 63625, 63732, 63833, 63929, 64019, 64104, 64104, 64184, 64260, 65536};
22. [*]         freq = notes[note];   // Determine frequency based on array value
23. [*]            INTCONbits.TMR0IF = 0;   // Clear OVF Flag
24. [*]            LATA = 0x01;   // Initialize LATA
25. [*]            TMR0L = freq & 0xFF;
26. [*]            TMR0H = (freq >> 8) & 0xFF;
27. [*]            T0CON|=0x80;
28. [*]            for(times=timer;times>0;times--)   // Duration of playing
29. [*]            {
30. [*]                TMR0H = (freq >> 8) & 0xFF;   //Load TMR0H byte first
31. [*]                TMR0L = freq & 0xFF;   // Load TMR0L byte next
32. [*]                while(!INTCONbits.TMR0IF);   // Wait for timer
33. [*]`                            INTCONbits.TMR0IF = 0;   // Clear OVF Flag
34. [*]                                LATA = ~LATA;   // Invert output
35. [*]            }
36. [*]                PAUSE;
37. [*]        }
38. [*]void playSong(unsigned int song)
39. [*]{
40. [*]        int time, note, counter;
41. [*]while(1)
42. [*]{
43. [*]        if(song==0)     // Song 1
44. [*]        {
45. [*]                for(counter=0;counter<53;counter++)
46. [*]                {
47. [*]                        note = songs[0][counter];       // Song 1 notes
48. [*]                        time = songs[1][counter];       // Song 1 time values
49. [*]                        playNote(note, time);   // Play through notes and times
50. [*]                }
51. [*]        break;  // When song 1 finishes, break
52. [*]        }
53. [*]        else if(song==1)        // Song 2
54. [*]        {
55. [*]                for(counter=0;counter<63;counter++)
56. [*]                {
57. [*]                        note = songs[2][counter];       // Song 2 notes
58. [*]                        time = songs[3][counter];       // Song 2 time values
59. [*]                        playNote(note, time);   // Play through notes and times
60. [*]                }
61. [*]        break;  // When song 2 finishes, break
62. [*]        }
63. [*]        else if(song==2)        // Song 3
64. [*]        {
65. [*]                for(counter=0;counter<80;counter++)
66. [*]                {
67. [*]                        note = songs[4][counter];       // Song 3 notes
68. [*]                        time = songs[5][counter];       // Song 3 time values
69. [*]                        playNote(note, time);      // Play through notes and times
70. [*]                }
71. [*]        break;  // When song 3 finishes, break
72. [*]        }
73. [*]        else
74. [*]        {
75. [*]                LATB = 0x08;    // Otherwise, LED 4
76. [*]        }
77. [*] }
78. [*]}
79. [*]        void main()
80. [*]        {
81. [*]        ADCON1 = 0x0E;  // ADC Settings as digital inputs from RA1-RA3
82. [*]        OSCCONbits.IRCF0=1;
83. [*]        OSCCONbits.IRCF1=1;
84. [*]        OSCCONbits.IRCF2=1;
85. [*]        T0CONbits.TMR0ON = 0;   // Don't turn timer on yet
86. [*]        T0CONbits.T08BIT = 0;   // Timer0 is configured as 16-bit timer
87. [*]        T0CONbits.T0CS = 0;       // Use internal clock
88. [*]        T0CONbits.PSA = 1;   // Prescaler is not assigned
89. [*]        T0CONbits.T0PS2 = 0;
90. [*]        T0CONbits.T0PS1 = 0;
91. [*]        T0CONbits.T0PS0 = 0;
92. [*]        while(!OSCCONbits.IOFS);
93. [*]        TRISA = 0xFE;
94. [*]        TRISB = 0xF0;
95. [*]        while(1)
96. [*]        {
97. [*]               switch(PORTA & 0x0E)
98. [*]               {
99. [*]                case 0x0C:
100. [*]                        LATB = 0x01;
101. [*]                        playSong(0);
102. [*]                        break;
103. [*]                case 0x0A:
104. [*]                        LATB = 0x02;
105. [*]                        playSong(1);
106. [*]                        break;
107. [*]                case 0x06:
108. [*]                        LATB = 0x04;
109. [*]                        playSong(2);
110. [*]                        break;
111. [*]                default:
112. [*]                        LATB = 0x08;
113. [*]                }
114. [*]         }
115. [*]}
116. [/LIST]
117. [/FONT]
118.
119.
I also have a video of it in action: