External Interrupt

[anthonyverfaill]

I am using the KL25Z with code warrior (10.5) for the IDE. I need a external push button that will interrupt my code so that I can have some timers and other bits performed. 

Anyone have a simple push button interrupt example I could take a look at? Any help would be appreciated. 

[Alice_Yang]

Hello Anthony ,

You can configure a gpio interrupt , then in the interrupt function you can performed

some actions.

About the example code , you can add Processor Expert component for GPIO, there is

a demo code you can refer to :

Hope it helps

Have a great day,
TIC

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[anthonyverfaill]

Thank you for the reply. I unfortunately am lacking in the skills to pull

this off. Could you please provide some more details? For instance , for

the interrupt do i tie the pin to ground via the button? Is that what

triggers the interrupt?

I am doing a project and need a simple push button that can stop my code I

already have completed.

The idea is the “user” can interact via this simple button and in a sense

communicat with the device. Just a true false situation.

I have tried and tried but not having much luck with it. Any help would be

greatly appreciated.

[Alice_Yang]

Hello Anthony Verfaillie,

1. There are five methods can trigger the interrupt ， please have a look at Reference manual for your chip:

For example , if you want to connect one pin to ground to trigger an interrupt, you can configure the IRQC to

1000 .

2. Sorry I haven't install CW10.5, I use the latest verion CW11, while it is the same , I create a simple

project , about the pin interrupt,  the main initialize code as below:

If you do not want to use Processor Expert ,you can refer to the code write your own code .

If there is problem on your code, you can send it to me .

And add your interrupt code under the below function, or you can also write by yourself.

Hope it helps

Have a great day,
TIC

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[anthonyverfaill]

I used what you have sent me with a simple example that evidently at one time worked. My issue is the interrupt handles function. I am not sure how I should read what i assume is a flag that goes high? It looks like in the code fired is the interrupt pin going high? Im just not sure at all.

[Alice_Yang]

Hi  Anthony,

Sorry I just can't know your question very clearly now.

Do you mean when run your code ,when the PTA0 is high, then run into interrupt function ?

How do you judged ?

If I misunderstood your question , please describe it more detail , thank you .

BR

Alice

[anthonyverfaill · Accepted solution]

Thank you for the reply. I have resolved my problem with the accelerometer. However, I do have a new question.

I want to use a push button switch that i will connect to ground and pin PTA5. i then want to read PTA5 when I press the button and have my program (do something)

Setting are below. Should I set the pull up resistor also? And how do I read PTA5, should I read the memory location?

/* Turn on clock to PortA module */

SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;

/* Set the PTB18 pin multiplexer to GPIO mode */

PORTA_PCR5 = PORT_PCR_MUX(1);

/* Set the pins direction to input */

GPIOA_PDDR |= (0<<5);