LED blinks on PF2 until the switch SW1 is pressed

Nabila Naorin

Hi I am trying to write a code where the blue LED will blink unless i press the SW1.

TExaS_Init(SW_PIN_PF4, LED_PIN_PF2);

GPIO_PORTF_AMSEL_R=~0X14//DISABLE ANALOG PF2,PF4
GPIO_PORTF_PCTL_R=~0X000F0F00//CLEAR PF2,PF4 BIT FIELDS IN PCTL
GPIO_PORTF_AFSEL_R=~0X14//ALTERNATE FUNCITON OFF PF2,PF4
GPIO_PORTF_DEN_R=0X14//DIGITAL ENABLED PF2,PF4
GPIO_PORTF_PUR_R=0X10//PUR ON PF4
GPIO_PORTF_DATA_R=0X04//LED ON

Delay100ms(100);//DELAY FOR 100 MS
If(SW_PIN_PF4==1){//Read the switch and test if the switch is pressed
while(1){
GPIO_PORTF_DATA_R^0x04

}
}

void Delay100ms(unsigned long time){
unsigned long i;
while(time > 0){
i = 1333333; // this number means 100ms
while(i > 0){
i = i - 1;
}
time = time - 1; // decrements every 100 ms
}
}

Am i doing anything wrong? It's not showing the desired output

Thanks

Nabila

over 11 years ago

0 Amit Ashara over 11 years ago

TI__Guru**** 244400 points

Hi Nabila,

I am not sure about the code but logically If the intent is to blink when switch is not pressed then

while(1) {

if(switch is pressed) {

LED OFF

} else {

LED ON

Delay

LED OFF

Delay

}

Regards

Amit Ashara

0 Nabila Naorin over 11 years ago in reply to Amit Ashara

Intellectual 600 points

Thank you very much. Do yuo know how to unlock GPIO_CR. It is showing me an error stating to unlock GPIO_CR first?

Thanks

Nabila

0 Nabila Naorin over 11 years ago in reply to Nabila Naorin

Intellectual 600 points

the bits should be set to 1 in order to clear off.. but it's showing error

0 Amit Ashara over 11 years ago in reply to Nabila Naorin

TI__Guru**** 244400 points

Hi Nabila,

PF0 is locked. The GPIOCR bits for the other pins in PF should be 1. If they are not 1 then first you have to write to the GPIOLOCK register, the unlock key and then set the corresponding bit for the pin in GPIOCR.

By the way what is giving an error, compilation,??? It was not clear when reading the post

Regards

Amit Ashara

0 Nabila Naorin over 11 years ago in reply to Nabila Naorin

Intellectual 600 points

Thanks. The error is:

Error: attempt to change CR while locked. You should unlock first
Error: attempting to change AFSEL while CR bits are zero. You should set CR first

I tried GPIO_CR=0xFE, but is is showing both the errors above

Regards

Nabila

0 Amit Ashara over 11 years ago in reply to Nabila Naorin

TI__Guru**** 244400 points

Hi Nabila

GPIOLOCK has to be written with 0x4C4F434B to unlock first. That should take care of the errors

Regards

Amit Ashara

0 Nabila Naorin over 11 years ago in reply to Amit Ashara

Intellectual 600 points

Thank you. Sorry for troubling you. What code should i use to unlock gpiocr.. i tried the base for port f which is 0x4002.5000

Can you please tell me the page no. for unlocking these registers

It is now showing me one error regarding gpio_cr,GPIO_lock is fine now. Thanks for that

REgards

0 Nabila Naorin over 11 years ago in reply to Nabila Naorin

Intellectual 600 points

got it..it's 0x1F

Arm-based microcontrollers

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LED blinks on PF2 until the switch SW1 is pressed