Sound Library
The mikroC PRO for PIC provides a Sound Library to supply users with routines necessary for sound signalization in their applications. Sound generation needs additional hardware, such as piezo-speaker (example of piezo-speaker interface is given on the schematic at the bottom of this page).
Library Routines
Sound_Init
Prototype |
void Sound_Init(char *snd_port, char snd_pin); |
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Returns |
Nothing. |
Description |
Configures the appropriate MCU pin for sound generation. Parameters :
|
Requires |
Nothing. |
Example |
// Initialize the pin RC3 for playing sound Sound_Init(&PORTC, 3); |
Sound_Play
Prototype |
void Sound_Play(unsigned freq_in_hz, unsigned duration_ms); |
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Returns |
Nothing. |
Description |
Generates the square wave signal on the appropriate pin. Parameters :
Note :
Frequency range is limited by Delay_Cyc parameter. Maximum frequency that can be produced by this function is
Freq_max = Fosc/(80*3) . Minimum frequency is Freq_min = Fosc/(80*255) . Generated frequency may differ from the freq_in_hz parameter due to integer arithmetics.
|
Requires |
In order to hear the sound, you need a piezo speaker (or other hardware) on designated port. Also, you must call Sound_Init to prepare hardware for output before using this function. |
Example |
// Play sound of 1KHz in duration of 100ms Sound_Play(1000, 100); |
Library Example
The example is a simple demonstration of how to use the Sound Library for playing tones on a piezo speaker.
void Tone1() { Sound_Play(659, 250); // Frequency = 659Hz, duration = 250ms } void Tone2() { Sound_Play(698, 250); // Frequency = 698Hz, duration = 250ms } void Tone3() { Sound_Play(784, 250); // Frequency = 784Hz, duration = 250ms } void Melody() { // Plays the melody "Yellow house" Tone1(); Tone2(); Tone3(); Tone3(); Tone1(); Tone2(); Tone3(); Tone3(); Tone1(); Tone2(); Tone3(); Tone1(); Tone2(); Tone3(); Tone3(); Tone1(); Tone2(); Tone3(); Tone3(); Tone3(); Tone2(); Tone2(); Tone1(); } void ToneA() { Sound_Play( 880, 50); } void ToneC() { Sound_Play(1046, 50); } void ToneE() { Sound_Play(1318, 50); } void Melody2() { unsigned short i; for (i = 9; i > 0; i--) { ToneA(); ToneC(); ToneE(); } } void main() { ANSEL = 0; // Configure AN pins as digital ANSELH = 0; C1ON_bit = 0; // Disable comparators C2ON_bit = 0; TRISB = 0xF8; // Configure RB7..RB3 as input Sound_Init(&PORTC, 3); Sound_Play(880, 1000); // Play sound at 880Hz for 1 second while (1) { if (Button(&PORTB,7,1,1)) // RB7 plays Tone1 Tone1(); while (RB7_bit) ; // Wait for button to be released if (Button(&PORTB,6,1,1)) // RB6 plays Tone2 Tone2(); while (RB6_bit) ; // Wait for button to be released if (Button(&PORTB,5,1,1)) // RB5 plays Tone3 Tone3(); while (RB5_bit) ; // Wait for button to be released if (Button(&PORTB,4,1,1)) // RB4 plays Melody2 Melody2(); while (RB4_bit) ; // Wait for button to be released if (Button(&PORTB,3,1,1)) // RB3 plays Melody Melody(); while (RB3_bit) ; // Wait for button to be released } }
HW Connection
Example of Sound Library connection
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