EK-LM3S8962开发板上实现蜂鸣器播放《梁祝》

// Header: Copyright (c) L.Luo // File Name: Music.c via LM3S8962 Kit // Author: L.Luo // Date: 10.05,2010,Eveing #include <LM3Sxxxx.h> // 定义系统时钟 8M #define TheSysClock 8000000 // 全局变量 unsigned long g_ulFrequency; unsigned long g_ulDutyCycle; // 定义低音音名（数值单位：Hz） #define L1 262 // c #define L2 294 // d #define L3 330 // e #define L4 349 // f #define L5 392 // g #define L6 440 // a1 #define L7 494 // b1 // 定义中音音名 #define M1 523 // c1 #define M2 587 // d1 #define M3 659 // e1 #define M4 698 // f1 #define M5 784 // g1 #define M6 880 // a2 #define M7 988 // b2 // 定义高音音名 #define H1 1047 // c2 #define H2 1175 // d2 #define H3 1319 // e2 #define H4 1397 // f2 #define H5 1568 // g2 #define H6 1760 // a3 #define H7 1976 // b3 // 定义时值单位，决定演奏速度（数值单位：ms） #define T 3600 // 定义音符结构 typedef struct { short mName; // 音名：取值L1～L7、M1～M7、H1～H7分别表示低音、中音、高音的 // 1234567，取值0表示休止符 short mTime; // 时值：取值T、T/2、T/4、T/8、T/16、T/32分别表示全音符、 // 二分音符、四分音符、八分音符…，取值0表示演奏结束 }tNote; // 定义乐曲：《化蝶》（梁祝） const tNote MyScore[] = { {L3, T/4}, {L5, T/8+T/16}, {L6, T/16}, {M1, T/8+T/16}, {M2, T/16}, {L6, T/16}, {M1, T/16}, {L5, T/8}, {M5, T/8+T/16}, {H1, T/16}, {M6, T/16}, {M5, T/16}, {M3, T/16}, {M5, T/16}, {M2, T/2}, {M2, T/8}, {M2, T/16}, {M3, T/16}, {L7, T/8}, {L6, T/8}, {L5, T/8+T/16}, {L6, T/16}, {M1, T/8}, {M2, T/8}, {L3, T/8}, {M1, T/8}, {L6, T/16}, {L5, T/16}, {L6, T/16}, {M1, T/16}, {L5, T/2}, {M3, T/8+T/16}, {M5, T/16}, {L7, T/8}, {M2, T/8}, {L6, T/16}, {M1, T/16}, {L5, T/8}, {L5, T/4}, {L3, T/16}, {L5, T/16}, {L3, T/8}, {L5, T/16}, {L6, T/16}, {L7, T/16}, {M2, T/16}, {L6, T/4+T/8}, {L5, T/16}, {L6, T/16}, {M1, T/8+T/16}, {M2, T/16}, {M5, T/8}, {M3, T/8}, {M2, T/8}, {M3, T/16}, {M2, T/16}, {M1, T/8}, {L6, T/16}, {L5, T/16}, {L3, T/4}, {M1, T/4}, {L6, T/16}, {M1, T/16}, {L6, T/16}, {L5, T/16}, {L3, T/16}, {L5, T/16}, {L6, T/16}, {M1, T/16}, {L5, T/2}, { 0, T/4}, { 0, T/4}, { 0, 0} // 结束 }; // 蜂鸣器外设初始化 void io_init(void) { unsigned long ulPWMClock; SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_XTAL_8MHZ | SYSCTL_OSC_MAIN); // Enable GPIO bank F to allow control of the LED. SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF); // Configure Port F0 for as an output for the status LED. GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE,GPIO_PIN_0); // Initialize LED to OFF (0) GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_0, 0); // Enable Port G1 for PWM output. SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOG); GPIOPinTypePWM(GPIO_PORTG_BASE,GPIO_PIN_1); // Enable the PWM generator. SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM); // Configure the PWM generator for count down mode with immediate updates // to the parameters. PWMGenConfigure(PWM_BASE, PWM_GEN_0, PWM_GEN_MODE_DOWN | PWM_GEN_MODE_NO_SYNC); // Divide the PWM clock by 1. SysCtlPWMClockSet(SYSCTL_PWMDIV_1); // Get the PWM clock. ulPWMClock = SysCtlClockGet(); // Intialize the PWM frequency and duty cycle. g_ulFrequency = 440; g_ulDutyCycle = 25; // Set the period of PWM1. PWMGenPeriodSet(PWM_BASE, PWM_GEN_0, ulPWMClock / g_ulFrequency); // Set the pulse width of PWM1. PWMPulseWidthSet(PWM_BASE, PWM_OUT_1, ((ulPWMClock * g_ulDutyCycle)/100) / g_ulFrequency); // Start the timers in generator 0. PWMGenEnable(PWM_BASE, PWM_GEN_0); } // Set the status LED on or off. void io_set_led(tBoolean bOn) { // Turn the LED on or off as requested. GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_0, bOn ? GPIO_PIN_0 : 0); } // Turn PWM on/off void io_set_pwm(tBoolean bOn) { // Enable or disable the PWM1 output. PWMOutputState(PWM_BASE, PWM_OUT_1_BIT, bOn); } // Set PWM Frequency void io_pwm_freq(unsigned long ulFreq) { unsigned long ulPWMClock; // Get the PWM clock ulPWMClock = SysCtlClockGet(); // Set the global frequency g_ulFrequency = ulFreq; // Set the period. PWMGenPeriodSet(PWM_BASE, PWM_GEN_0, ulPWMClock / g_ulFrequency); // Set the pulse width of PWM1 PWMPulseWidthSet(PWM_BASE, PWM_OUT_1, ((ulPWMClock * g_ulDutyCycle)/100) / g_ulFrequency); } // Set PWM Duty Cycle void io_pwm_dutycycle(unsigned long ulDutyCycle) { unsigned long ulPWMClock; // Get the PWM clock ulPWMClock = SysCtlClockGet(); // Set the global duty cycle g_ulDutyCycle = ulDutyCycle; // Set the period. PWMGenPeriodSet(PWM_BASE, PWM_GEN_0, ulPWMClock / g_ulFrequency); // Set the pulse width of PWM1 PWMPulseWidthSet(PWM_BASE, PWM_OUT_1, ((ulPWMClock * g_ulDutyCycle)/100) / g_ulFrequency); } // 演奏乐曲， 在PWM发声的同时点亮LED灯，反之熄灭 void MusicPlay(void) { int i = 0; for (;;) { if (MyScore[i].mTime == 0) { break; } io_pwm_freq(MyScore[i].mName); io_set_pwm(1); io_set_led(1); SysCtlDelay(MyScore[i].mTime * (TheSysClock / 2000)); i++; io_set_pwm(0); io_set_led(0); SysCtlDelay(10 * (TheSysClock / 2000)); } } // 主程序，演奏《梁祝》 int main() { io_init(); io_set_led(1); io_set_pwm(1); while(1) { MusicPlay(); SysCtlDelay(2000 * (TheSysClock / 2000)); }; }