SparkFun Forums 

Where electronics enthusiasts find answers.

Your source for all things Atmel.
By Doenges

i'm trying at the moment to execute a simple interrupt through a Button (Button2) while a LED is blinking, but nothing happens!
I've got the EK Boad from Olimex.
The button is connected with PA20 which is also IRQ0.

Would be great is someone have 2-3 minutes to have a look on m code, thanks!

Regards from cologne!


#include "AT91SAM7S256.h"
#include "board.h"
#include "delay.h"
#include "stdlib.h"
#include "string.h"

void button2irqhandler (void);
extern void LowLevelInit(void);
extern unsigned enableIRQ(void);
void LowLevelInit();

int main (void) {

// Set up the LEDs (PA0 - PA3)
volatile AT91PS_PIO pPIO = AT91C_BASE_PIOA; // pointer to PIO
data structure
pPIO->PIO_PER = LED_MASK | Button2; // PIO Enable Register -
allow PIO to control pins P0 - P2 and pin 19
pPIO->PIO_OER = LED_MASK; // PIO Output Enable Register -
sets pins P0 - P2 to outputs
pPIO->PIO_SODR = LED_MASK; // PIO Set Output Data
Register - turns off the two LEDs

// Select PA20 (pushbutton) to be IRQ function (Peripheral B)
pPIO->PIO_BSR = Button2;

// Set up the AIC registers for Button2
volatile AT91PS_AIC pAIC = AT91C_BASE_AIC; // pointer to AIC
data structure
pAIC->AIC_IDCR = (1<<AT91C_ID_IRQ0); // Disable IRQ0 interrupt
in AIC Interrupt Disable Command Register
pAIC->AIC_SVR[AT91C_ID_IRQ0] = // Set the Button2 IRQ0
handler address in AIC Source
(unsigned int)button2irqhandler; // Vector Register[30]
pAIC->AIC_SMR[AT91C_ID_IRQ0] = // Set the interrupt source
type and priority
(AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL | 0x4 ); // in AIC Source Mode
pAIC->AIC_ICCR = (1<<AT91C_ID_IRQ0); // Clear the IRQ0
interrupt in AIC Interrupt Clear Command Register
pAIC->AIC_IDCR = (0<<AT91C_ID_IRQ0); // Remove disable IRQ0
interrupt in AIC Interrupt Disable Command Reg
pAIC->AIC_IECR = (1<<AT91C_ID_IRQ0); // Enable the IRQ0
interrupt in AIC Interrupt Enable Command Register

while (1) {
if ((pPIO->PIO_ODSR & LED1) == LED1) { // read previous state
of LED1
} else {
#include "AT91SAM7S256.h"
#include "board.h"

void button2irqhandler (void) {

volatile AT91PS_TC pTC = AT91C_BASE_TC0; // pointer to timer
channel 0 register structure
volatile AT91PS_PIO pPIO = AT91C_BASE_PIOA; // pointer to PIO
register structure
unsigned int dummy; // temporary

dummy = pTC->TC_SR; // read TC0 Status Register to
clear interrupt

if ((pPIO->PIO_ODSR & LED2) == LED2) {
pPIO->PIO_CODR = LED2; // turn LED2 (DS2) on

} else {
pPIO->PIO_SODR = LED2; // turn LED2 (DS2) off


unsigned enableIRQ(void)
unsigned _cpsr;

_cpsr = __get_cpsr();
__set_cpsr(_cpsr & ~IRQ_MASK);
return _cpsr;
long long title how many chars? lets see 123 ok more? yes 60

We have created lots of YouTube videos just so you can achieve [...]

Another post test yes yes yes or no, maybe ni? :-/

The best flat phpBB theme around. Period. Fine craftmanship and [...]

Do you need a super MOD? Well here it is. chew on this

All you need is right here. Content tag, SEO, listing, Pizza and spaghetti [...]

Lasagna on me this time ok? I got plenty of cash

this should be fantastic. but what about links,images, bbcodes etc etc? [...]