MSP430 按鍵程序 (含電路圖及源代碼)

＃i nclude <msp430x14x.h>
void Init_Port(void)
{
??? //將P1口所有的管腳在初始化的時候設置為輸入方式
??? P1DIR = 0;
?
??? //將P1口所有的管腳設置為一般I/O口
??? P1SEL = 0;
???
??? // 將P1.4 P1.5 P1.6 P1.7設置為輸出方向
??? P1DIR |= BIT4;
??? P1DIR |= BIT5;
?P1DIR |= BIT6;
??? P1DIR |= BIT7;

?//先輸出低電平
?P1OUT = 0x00;

?// 將中斷寄存器清零
??? P1IE = 0;
??? P1IES = 0;
??? P1IFG = 0;
??? //打開管腳的中斷功能
?//對應的管腳由高到低電平跳變使相應的標志置位
??? P1IE |= BIT0;?
??? P1IES |= BIT0;?
??? P1IE |= BIT1;?
??? P1IES |= BIT1;
?P1IE |= BIT2;?
??? P1IES |= BIT2;?
??? P1IE |= BIT3;?
??? P1IES |= BIT3;
?_EINT();//打開中斷
??? return;
}
void Delay(void)
{
?int i;
?for(i = 100;i--;i > 0) ;//延時一點時間
}
int KeyProcess(void)
{
??? int nP10,nP11,nP12,nP13;
?int nRes = 0;
?//P1.4輸出低電平
?P1OUT &= ~(BIT4);
?nP10 = P1IN & BIT0;
?if (nP10 == 0) nRes = 13;
?nP11 = P1IN & BIT1;
?if (nP11 == 0) nRes = 14;
?nP12 = P1IN & BIT2;
?if (nP12 == 0) nRes = 15;
?nP13 = P1IN & BIT3;
?if (nP13 == 0) nRes = 16;
?//P1.5輸出低電平
?P1OUT &= ~(BIT4);
?nP10 = P1IN & BIT0;
?if (nP10 == 0) nRes = 9;
?nP11 = P1IN & BIT1;
?if (nP11 == 0) nRes = 10;
?nP12 = P1IN & BIT2;
?if (nP12 == 0) nRes = 11;
?nP13 = P1IN & BIT3;
?if (nP13 == 0) nRes = 12;
?//P1.6輸出低電平
?P1OUT &= ~(BIT4);
?nP10 = P1IN & BIT0;
?if (nP10 == 0) nRes = 5;
?nP11 = P1IN & BIT1;
?if (nP11 == 0) nRes = 6;
?nP12 = P1IN & BIT2;
?if (nP12 == 0) nRes = 7;
?nP13 = P1IN & BIT3;
?if (nP13 == 0) nRes = 8;
?//P1.7輸出低電平
?P1OUT &= ~(BIT4);
?nP10 = P1IN & BIT0;
?if (nP10 == 0) nRes = 1;
?nP11 = P1IN & BIT1;
?if (nP11 == 0) nRes = 2;
?nP12 = P1IN & BIT2;
?if (nP12 == 0) nRes = 3;
?nP13 = P1IN & BIT3;
?if (nP13 == 0) nRes = 4;

?P1OUT = 0x00;//恢復以前值。

?//讀取各個管腳的狀態
?nP10 = P1IN & BIT0;
?nP11 = P1IN & BIT1;
?nP12 = P1IN & BIT2;
?nP13 = P1IN & BIT3;
?for(;;)
?{
??if(nP10 == 1 && nP11 == 1 && nP12 == 1 && nP13 == 1)
??{
???//等待松開按鍵
???break;
??}
?}
?return nRes;
}
// 處理來自端口 1 的中斷
interrupt [PORT1_VECTOR] void PORT_ISR(void)
{
?Delay();
?KeyProcess();
??? if(P1IFG & BIT0)
??? {??? ?
??? ?P1IFG &= ~(BIT0);// 清除中斷標志位
??? }
??? if(P1IFG & BIT1)
??? {
??? ?P1IFG &= ~(BIT1);// 清除中斷標志位
??? }
??? if(P1IFG & BIT2)
??? {
??? ?P1IFG &= ~(BIT2);// 清除中斷標志位
??? }
?if(P1IFG & BIT3)
??? {
??? ?P1IFG &= ~(BIT3);// 清除中斷標志位
??? }
}
void Init_CLK(void)
{
??? unsigned int i;
??? BCSCTL1 = 0X00;???//將寄存器的內容清零
?????//XT2震蕩器開啟
?????//LFTX1工作在低頻模式
?????//ACLK的分頻因子為1
?????
??? do
??? {
?IFG1 &= ~OFIFG;?????????????????????? // 清除OSCFault標志
?for (i = 0x20; i > 0; i--);???????????????
??? }
??? while ((IFG1 & OFIFG) == OFIFG);????? // 如果OSCFault =1??
?????
??? BCSCTL2 = 0X00;???//將寄存器的內容清零
??? BCSCTL2 += SELM1;??//MCLK的時鐘源為TX2CLK，分頻因子為1
??? BCSCTL2 += SELS;??//SMCLK的時鐘源為TX2CLK，分頻因子為1
}

MSP430按鍵接口電路圖

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