[After-class Exercise] After-class Exercise 2 IO Interruption

常见泽1

[After-class Exercise] After-class Exercise 2 IO Interruption [Copy link]

After-class Exercise 2 IO Interruption

1. First look at the schematic diagram

2. Pin settings

PxDIR Input / Output Direction Register

PxIN Input Register

PxOUT Output Register

PxIFG Interrupt Flag Register

PxIE Interrupt Enable Register

PxSEL Function Selection Register

3. Application

Application 1: Key as interrupt

P1.3 —— key as interrupt

Reference books,

(1) If some pins of port P1 are used as interrupt mode, be sure to set the corresponding bits of the P1IFG , P1IES , and P1IE registers before opening the general interrupt , and ensure that the corresponding pins are in the input direction.

(2) To minimize power consumption, the connected pins should be set to IO functions and set to output.

(3) The interrupt flag needs to be cleared by software

Question 1 : Some people see the program saying that the general interrupt is __enable_interrupt

Some people say that the general interrupt is _EINT()

In fact, both are correct, look at the header file.

/* Deprecated, please use "__disable_interrupt" instead. */

#define _DINT() __disable_interrupt()

/* Deprecated, please use "__enable_interrupt" instead. */

#define _EINT() __enable_interrupt()

/* Deprecated, please use "__no_operation" instead. */

#define _NOP() __no_operation()

Question 2 : I used someone else's IO interrupt to light up , but it doesn't enter the interrupt every time

Later I found out that key interrupts also need to be debounced.

for(i=0;i<0x1fff;i++); // Debounce is essential!!

Question 3 : XOR negation

Question 4 : The interrupt flag needs to be cleared by software and needs to be cleared for each interrupt.

常见泽1

1. 
   /***************************************************
   **** LAUNCH PAD Learning GPIOINT ***
   **** MCU: MSP430 ***
   **** Author: Chang Jianze***
   **** ***
   **** ***
   **** 2012.05.24.20:16 ***
   **** Experimental phenomenon: Press the button***
   **** Interrupt enable register only has P1P2***
   **** Press the button once, the LED turns on or off once***
   ***********************************************/
   
   #include
   
   void Key_init(void)
   {
   P1REN |= BIT3; //Turn on the pull-up, there is no pull-up resistor on the circuit board, and the trigger edge is from high level to low level
   P1IES |= BIT3; //Select the trigger edge, the falling edge triggers
   P1IE |= BIT3; //Turn on the interrupt of P1.3
   P1IFG &= 0x00;
   }
   
   void main(void)
   {
   WDTCTL = WDTPW + WDTHOLD; // Turn off the watchdog
   
   P1DIR |= BIT0; //Set the P1.0 pin to output
   P1OUT |= BIT0; //P1.0 pin outputs low level
   Key_init(); //Call IO interrupt initialization function
   
   _EINT(); //Turn on the total interrupt. Without this step, all interrupts cannot be triggered
   
   while(1); //Infinite loop
   
   }
   
   #pragma vector = PORT1_VECTOR //Interrupt vector declaration
   __interrupt void Key_interrput(void)
   {
   unsigned int i;
   for(i=0;i<0x1fff;i++); //Debounce is essential! !
   if(P1IFG&BIT3) //Judge whether the P1.3 IO port has an interrupt
   { //If an interrupt occurs, P1IFG.3 is set to 1
   P1OUT ^= BIT0; //LED2 is inverted
   P1IFG &= 0x00; //The interrupt flag needs to be cleared by software! ! !
   P1REN |= BIT3;
   }
   }
   
   

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青云LI

:) Very good, very cool, thank you OP!

nishi666

Learn more

574937246

The OP is awesome~~~~ Keep posting good stuff~~~

常见泽1

Thank you for your support:kiss:

hai312546

Thank you so much to the OP, I have been struggling with this for a long time :Cry: , I strongly support the OP! ! ! ! ! ! !

常见泽1

This program can be implemented with MSPG2231, but the launchpad I sent now does not have MSPG2231. I have tried MSPG2542 and MSPG2253. This program does not work and needs to be modified slightly.

原理

Why doesn't it work? My chip is mspg2231. After I copied it completely, I pressed P3.1 once and LED0 went from bright to dark. But after that, no matter how I pressed the button, it didn't work and the light never came on.

常见泽1

I can do it here. I have tried two boards and they all work. I just tried G2231 and it works perfectly. But I have tried MSPG2542 and MSPG2253. It is very confusing to make small modifications.

常见泽1

It works here, but the delay time is a little short and a little jittery, but multiple key presses are definitely effective. There is no problem with the G2231 chip.

低c灰太狼

What if I have two interrupts? How do I choose after turning on the master interrupt? One is TIMER and the other is IO interrupt.

常见泽1

The interrupt flags of the two terminals are different

一潭清水

How to modify it?

常见泽1

Which chip do you have? I have tried 2553. I can increase the delay to eliminate jitter.

tyyl

:kiss: :hug:

mrm827915

I tried it with 2553, but it said there was no license or something like that. What's going on?

常见泽1

No license? Are you using the Harmony version? Is it Harmony OK? Can other programs be compiled?

mrm827915

Uninstall, download and install again, and it works. I would like to ask again~ Is it necessary to write P1REN=BIT3 in the program? In what circumstances must this be written?

常见泽1

P1REN is set up internally. See a picture in the manual.

If the port is connected to a button and no external pull-up is used, the internal pull-up should be turned on.

As for whether this sentence can be omitted

See the launchpad schematic

There is an external pull-up on the schematic

But there will be a difference in the actual product because the resistor R34 is installed externally. The launchpad I received was not soldered on. You can check if yours is soldered on.

If there is an external pull-up resistor, it can be omitted

I have 2 launchpads. One was purchased in a group. The one I purchased in a group had R34de, but the R34 that came with it was not soldered.

[ This post was last edited by Changjianze1 on 2012-7-11 23:07]