让你的Launchpad/RF2500控制音乐播放

cc1989summer 2011-7-8 16:36 楼主

接上篇https://bbs.eeworld.com.cn/thread-294145-1-1.html

TI 给出了Capacitive Touch BoosterPack（触摸板）附带的上位机软件软件。

MediaPad.rar (254.02 KB)
(下载次数: 131, 2011-7-8 16:36 上传)

而该软件即具有控制音乐播放之功能，用户接口就是串口，相应指令即可实现相应的控制功能。

打开播放器 80 80
播放暂停 38 38 38 38
下一曲 34 34 34 34

上一曲 3C 3C 3C 3C

以上是本人暂时得出控制指令，向串口发送相应指令（比如发送4次0x34即可下一曲）

另外可以实现音量加减，但暂时没搞定对应指令。

具体到Launchpad,我们可以利用它的定时器模拟串口，

代码如下：

#include "msp430g2452.h"

//------------------------------------------------------------------------------
// Hardware-related definitions
//------------------------------------------------------------------------------
#define UART_TXD 0x02 // TXD on P1.1 (Timer0_A.OUT0)
#define UART_RXD 0x04 // RXD on P1.2 (Timer0_A.CCI1A)

//------------------------------------------------------------------------------
// Conditions for 9600 Baud SW UART, SMCLK = 1MHz
//------------------------------------------------------------------------------
#define UART_TBIT_DIV_2 (1000000 / (9600 * 2))
#define UART_TBIT (1000000 / 9600)

//------------------------------------------------------------------------------
// Global variables used for full-duplex UART communication
//------------------------------------------------------------------------------
unsigned int txData; // UART internal variable for TX
unsigned char rxBuffer; // Received UART character
unsigned int i;

//------------------------------------------------------------------------------
// Function prototypes
//------------------------------------------------------------------------------
void TimerA_UART_init(void);
void TimerA_UART_tx(unsigned char byte);
void TimerA_UART_print(char *string);

void Delay(unsigned int i)
{
    while (i != 0)
    {
        i--;
    }
}
//------------------------------------------------------------------------------
// main()
//------------------------------------------------------------------------------
void main(void)
{
    WDTCTL = WDTPW + WDTHOLD;               // Stop watchdog timer

    DCOCTL = 0x00;                          // Set DCOCLK to 1MHz
    BCSCTL1 = CALBC1_1MHZ;
    DCOCTL = CALDCO_1MHZ;

    P1OUT = 0x00;                           // Initialize all GPIO
    P1SEL = UART_TXD + UART_RXD;            // Timer function for TXD/RXD pins
    P1DIR = 0x43;              // Set all pins but RXD to output

   __enable_interrupt();

while (1) // 按键消抖

{
    if ((0x08 & P1IN) == 0x00)
    {
      for(int i=0;i<4000;i++);
        if ((0x08 & P1IN) == 0x08)
        {
       P1OUT |= BIT6;
       TimerA_UART_init();                     // Start Timer_A UART
       TimerA_UART_tx(0x34);                //发送4次0x34实现下一曲

TimerA_UART_tx(0x34);
       TimerA_UART_tx(0x34);
       TimerA_UART_tx(0x34);
        }
    }
}
}
//------------------------------------------------------------------------------
// Function configures Timer_A for full-duplex UART operation
//------------------------------------------------------------------------------
void TimerA_UART_init(void)
{
    TACCTL0 = OUT;                          // Set TXD Idle as Mark = '1'
    TACCTL1 = SCS + CM1 + CAP + CCIE;       // Sync, Neg Edge, Capture, Int
    TACTL = TASSEL_2 + MC_2;                // SMCLK, start in continuous mode
}
//------------------------------------------------------------------------------
// Outputs one byte using the Timer_A UART
//------------------------------------------------------------------------------
void TimerA_UART_tx(unsigned char byte)
{
    while (TACCTL0 & CCIE);                 // Ensure last char got TX'd
    TACCR0 = TAR;                           // Current state of TA counter
    TACCR0 += UART_TBIT;                    // One bit time till first bit
    TACCTL0 = OUTMOD0 + CCIE;               // Set TXD on EQU0, Int
    txData = byte;                          // Load global variable
    txData |= 0x100;                        // Add mark stop bit to TXData
    txData <<= 1;                           // Add space start bit
}

//------------------------------------------------------------------------------
// Prints a string over using the Timer_A UART
//------------------------------------------------------------------------------
void TimerA_UART_print(char *string)
{
    while (*string) {
        TimerA_UART_tx(*string++);
    }
}
//------------------------------------------------------------------------------
// Timer_A UART - Transmit Interrupt Handler
//------------------------------------------------------------------------------
#pragma vector = TIMER0_A0_VECTOR
__interrupt void Timer_A0_ISR(void)
{
    static unsigned char txBitCnt = 10;

    TACCR0 += UART_TBIT;                    // Add Offset to CCRx
    if (txBitCnt == 0) {                    // All bits TXed?
        TACCTL0 &= ~CCIE;                   // All bits TXed, disable interrupt
        txBitCnt = 10;                      // Re-load bit counter
    }
    else {
        if (txData & 0x01) {
          TACCTL0 &= ~OUTMOD2;              // TX Mark '1'
        }
        else {
          TACCTL0 |= OUTMOD2;               // TX Space '0'
        }
        txData >>= 1;
        txBitCnt--;
    }
}
//------------------------------------------------------------------------------
// Timer_A UART - Receive Interrupt Handler
//------------------------------------------------------------------------------
#pragma vector = TIMER0_A1_VECTOR
__interrupt void Timer_A1_ISR(void)
{
    static unsigned char rxBitCnt = 8;
    static unsigned char rxData = 0;

    switch (__even_in_range(TA0IV, TA0IV_TAIFG)) { // Use calculated branching
        case TA0IV_TACCR1:                        // TACCR1 CCIFG - UART RX
            TACCR1 += UART_TBIT;                 // Add Offset to CCRx
            if (TACCTL1 & CAP) {                 // Capture mode = start bit edge
                TACCTL1 &= ~CAP;                 // Switch capture to compare mode
                TACCR1 += UART_TBIT_DIV_2;       // Point CCRx to middle of D0
            }
            else {
                rxData >>= 1;
                if (TACCTL1 & SCCI) {            // Get bit waiting in receive latch
                    rxData |= 0x80;
                }
                rxBitCnt--;
                if (rxBitCnt == 0) {             // All bits RXed?
                    rxBuffer = rxData;           // Store in global variable
                    rxBitCnt = 8;                // Re-load bit counter
                    TACCTL1 |= CAP;              // Switch compare to capture mode
                    __bic_SR_register_on_exit(LPM0_bits); // Clear LPM0 bits from 0(SR)
                }
            }
            break;
    }
}

具体到单机版（其中一个）的RF2500，代码如下：

#include "msp430x22x4.h"
void main(void)
{
WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
BCSCTL1 = CALBC1_1MHZ;                    // Set DCO
DCOCTL = CALDCO_1MHZ;

   P1DIR |= BIT0;
   P1OUT &=~BIT0;

P1DIR &= ~BIT2;     //P1.2口通过开关直接接地，设置为输入
P1REN |= BIT2;  //P1.2口开启上拉或者下拉电阻功能
P1OUT |= BIT2;  //选择上拉

P1IE |= BIT2;
P1IES &= ~BIT2;                       //上拉电阻，开关直接接地，应选择上升沿触发

   P3SEL = 0x30;                             // P3.4,5 = USCI_A0 TXD/RXD
UCA0CTL1 |= UCSSEL_2;                     // SMCLK
UCA0BR0 = 104;                            // 1MHz 9600
UCA0BR1 = 0;                              // 1MHz 9600
UCA0MCTL = UCBRS0;                        // Modulation UCBRSx = 1
UCA0CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
IE2 |= UCA0RXIE;                          // Enable USCI_A0 RX interrupt

__bis_SR_register(LPM0_bits + GIE);       // Enter LPM0, interrupts enabled

while(1);

}

// Port 1 interrupt service routine
#pragma vector=PORT1_VECTOR
__interrupt void Port_1(void)
{
   P1OUT ^= BIT0;

UCA0TXBUF = 0x34;
while (!(IFG2&UCA0TXIFG));              // USCI_A0 TX buffer ready?

    UCA0TXBUF = 0x34;
while (!(IFG2&UCA0TXIFG));              // USCI_A0 TX buffer ready?

    UCA0TXBUF = 0x34;
while (!(IFG2&UCA0TXIFG));              // USCI_A0 TX buffer ready?

    UCA0TXBUF = 0x34;
while (!(IFG2&UCA0TXIFG));              // USCI_A0 TX buffer ready?

P1IFG &= ~BIT2;                           // P1.2 IFG cleared
}