2-msp430 Key Input Detection

In order to write an article to pave the mat-remind yourself,,,,,,

P1.0 level, varies with the level change of the P1.1 pin input

#include"io430.h"voidDelayvoid) {unsignedCharA,b,c;  for(c=167;c>0; c--)         for(b=171;b>0; b--)             for(a=1;a>0; a--);}voidMainvoid) {Wdtctl= Wdtpw + wdthold;//The watchdog is turned on by default and is turned off without using it.P1dir =0x01;//P1.0 for Output mode   while(1) {P1out=0x01;//P1.0 output High leveldelay (); P1out=0x00;//P1.0 output Low leveldelay (); }}

There is such a definition in msp430 's header file

/*-------------------------------------------------------------------------* Standard Bits *------------------- ------------------------------------------------------*/#defineBIT0 (0x0001)#defineBIT1 (0x0002)#defineBIT2 (0x0004)#defineBIT3 (0x0008)#defineBIT4 (0x0010)#defineBIT5 (0x0020)#defineBIT6 (0x0040)#defineBIT7 (0x0080)#defineBIT8 (0x0100)#defineBIT9 (0x0200)#defineBita (0x0400)#defineBITB (0x0800)#defineBITC (0x1000)#defineBITD (0x2000)#defineBITE (0x4000)#defineBITF (0x8000)

So when setting P1.0 to output mode, you can

P1dir = BIT0;

Let's say we re-configure P1.1 as input mode.

If direct p1dir = 0x0001;

If you configure P1.2 for output mode later

P1dir = 0x0005;

This can be very cumbersome because the previous PIN configuration is considered

So when you configure a PIN as the output pin,

P1dir = P1dir |    0x0001 P1.0 for output

P1dir = P1dir |    0x0004 P1.2 for output

That

P1dir = P1dir |      BIT0; P1.0 for output

P1dir = P1dir |     BIT2; P1.2 for output

That

P1dir |= BIT0; P1.0 for output

P1dir |= BIT2; P1.2 for output

P1.1 when configured as input

P1dir &= 0xFFFD; P1.1 for input

That

P1dir &= ~bit1; P1.1 for input p1dir = P1dir & (~BIT1);

See if it doesn't affect each other.

P1dir |= BIT0; P1.0 for output p1dir = 0000 0000 0000 0000 0000 0000 0000 0001

P1dir |= BIT2; P1.2 for output p1dir = 0000 0000 0000 0000 0000 0000 0000 0101

P1dir &= ~bit1; P1.1 for input p1dir = 0000 0000 0000 0000 0000 0000 0000 0101

Now it seems that the orientation is not configured as input mode

#include"io430.h"voidMainvoid ){  //Stop watchdog timer to prevent time out resetWdtctl = Wdtpw +Wdthold; P1dir|= BIT0;//P1.0 for Output//p1dir &= BIT1;//P1.1 for input------shielding//p1dir |= bit6;//-----Shielding//p1out &= ~bit6;//------ShieldingP1dir|= BIT7;//P1.7 for output-------test not affectedP1out |= BIT7;//P1.7 output High level-------test not affected     while(1)  {    if(P1IN&BIT1)//#define BIT1 (0x0002) If the P1 input register p1in 1th bit is 1 o'clock{p1out|= BIT0;//P1.0 output high, without affecting other pins    }    if(! (P1IN&BIT1))//#define BIT1 (0x0002) If the P1 input register p1in 1th bit is 0 o'clock{p1out&= ~bit0;//P1.0 output low, without affecting other pins    }  }}

2-msp430 Key Input Detection