msp430-5438 鍵掃描

1、/* 工程名：msp430_project 作者： 模塊名稱：鍵掃描模塊（Nx(N-1)型鍵盤，N=5） 模塊描述：通過TIMER1A0中斷定時啟動鍵掃描.。 - - |msp430| p10.0 |5x4keyboard| |5438 | | | | | | p10.4 | | 版本：*/ #include msp430x54x.h #DEFINE uchar unsigned char#DEFINE uint unsigned int/*定義每個按鍵名及對應(yīng)值*/#DEFINE num0 0xf0 /*#DEFINE num0 0x00 不行，keybuff，keybufs初始化0x00*

2、/#DEFINE num1 0x01#DEFINE num2 0x02#DEFINE num3 0x03#DEFINE num4 0x04#DEFINE num5 0x05#DEFINE num6 0x06#DEFINE num7 0x07#DEFINE num8 0x08#DEFINE num9 0x09#DEFINE dirup 0x0a#DEFINE dirdown 0x0b#DEFINE dirleft 0x0c#DEFINE dirright 0x0d#DEFINE ctlenter 0x0e#DEFINE ctlshift 0x0f#DEFINE ctlclear 0x10#DEF

3、INE ctlexit 0x11#DEFINE ctlreset 0x12#DEFINE ctlstop 0x13/*定義全局變量*/ uchar keybuff=0x00;uchar keybufs=0x00;uchar keyvalue=0xff;uchar keyflag=0x00;/*timerA0 初始化*/void init_timera0(void) WDTCTL=WDTPW+WDTHOLD; /*CCR0中斷允許*/ TA1CCTL0 = CCIE; /*捕獲/比較寄存器設(shè)50ms中斷，（50/1000）*32768=1638*/ TA1CCR0 = 1638; /*使用327

4、68hz時鐘，增計數(shù)模式，ta清零*/ TA1CTL = TASSEL_1 + MC_1 + TACLR; #progma vector=TIMER1_A0_ISR(void)_interrupt void TIMER1_A0_ISR(void) keyscan(); /*每50ms更新一次max7219數(shù)據(jù)*/ led_show();/*鍵剛按下*/*第一次掃描到電平有變化時，按鍵值給keybuff，再keybufs=keybuff*/*50ms后掃描到電平有變化時，按鍵值給keybuff，再比較keybufs與keybuff是否相等：若相等，確定有鍵按下，值賦給keyvalue,keyfl

5、ag=0xff，keybuff，keybufs清零；不等keybuff，keybufs清零*/*健剛松開*/ /*第一次掃描到無變化時即keybuff=0x00，keybufs,keyflag清零,按鍵過程結(jié)束*/*鍵盤掃描模塊*/void keyscan(void) /*設(shè)置P10.0為輸出且輸出高電平，p10.1-p10.4為輸入*/ P10DIR | =0X01; P10OUT | =0x01; if(P10IN & 0x1e) ! =0) /*按鍵4*/ if(P10IN & BIT1) keybuff=num4; /*按鍵9*/ else if(P10IN & BIT2) keybu

6、ff=num9; /*按鍵exit*/ else if(P10IN & BIT3) keybuff=ctlexit; /*按鍵right*/ else if(P10IN & BIT4) keybuff=dirright; /*設(shè)置P10.1為輸出且輸出高電平，p10.0/p10.2/p10.3/p10.4為輸入*/ P10DIR | =0X02; P10OUT | =0x02; if(P10IN & 0x1d) ! =0) /*按鍵3*/ if(P10IN & BIT0) keybuff=num3; /*按鍵8*/ else if(P10IN & BIT2) keybuff=num8; /*按

7、鍵up*/ else if(P10IN & BIT3) keybuff=dirup; /*按鍵down*/ else if(P10IN & BIT4) keybuff=dirdown; /*設(shè)置P10.2為輸出且輸出高電平，p10.0/p10.1/p10.3/p10.4為輸入*/ P10DIR | =0X04; P10OUT | =0x04; if(P10IN & 0x1b) ! =0) /*按鍵2*/ if(P10IN & BIT0) keybuff=num2; /*按鍵7*/ else if(P10IN & BIT1) keybuff=num7; /*按鍵shift*/ else if(P

8、10IN & BIT3) keybuff=ctlshift; /*按鍵left*/ else if(P10IN & BIT4) keybuff=dirleft; /*設(shè)置P10.3為輸出且輸出高電平，p10.0/p10.1/p10.2/p10.4為輸入*/ P10DIR | =0X08; P10OUT | =0x08; if(P10IN & 0x17) ! =0) /*按鍵1*/ if(P10IN & BIT0) keybuff=num1; /*按鍵6*/ else if(P10IN & BIT1) keybuff=num6; /*按鍵reset*/ else if(P10IN & BIT2)

9、 keybuff=ctlreset; /*按鍵enter*/ else if(P10IN & BIT4) keybuff=ctlenter; /*設(shè)置P10.4為輸出且輸出高電平，p10.0/p10.1/p10.2/p10.3為輸入*/ P10DIR | =0X10; P10OUT | =0x10; if(P10IN & 0x0f) ! =0) /*按鍵0*/ if(P10IN & BIT0) keybuff=num0; /*按鍵5*/ else if(P10IN & BIT1) keybuff=num5; /*按鍵clear*/ else if(P10IN & BIT2) keybuff=ctlclear; /*按鍵stop*/ else if(P10IN & BIT3) keybuff=ctlstop; /*判斷是第一次還是第二次按下，做出對應(yīng)動作*/ /*是第一次按下 或 按鍵進(jìn)入穩(wěn)定狀態(tài)*/ if(keybuffs=0x00) keybuffs=keybuff; if(keybuff=0) /*沒鍵按下 或 已經(jīng)取鍵值（keybuff,keybufs復(fù)位，keyflag=0xff）,再次 掃描到無按鍵按下 */ keyflag=0x00; /*按下鍵中間時間段掃描時，清零keybufs，使?jié)M足上一層if條件，進(jìn)入本過程*/ if(keyflag=0xff)