RE: Timer interrupts

karthik999 — Fri, 08 Jun 2018 14:00:47 GMT

//#define TRIGGER_INTERVAL 100 // ms
int LED = 8;
//int LED1 = 7;
int i = 0;
void timer_config(void)
{
NRF_TIMER0->TASKS_STOP = 1; // Stop timer
NRF_TIMER0->MODE = TIMER_MODE_MODE_Timer; // taken from Nordic dev zone
NRF_TIMER0->BITMODE = (TIMER_BITMODE_BITMODE_24Bit << TIMER_BITMODE_BITMODE_Pos);
NRF_TIMER0->PRESCALER = 8; // 1us resolution
NRF_TIMER0->TASKS_CLEAR = 1; // Clear timer
NRF_TIMER0->CC[0] = 62500;
NRF_TIMER0->INTENSET = TIMER_INTENSET_COMPARE0_Enabled << TIMER_INTENSET_COMPARE0_Pos; // taken from Nordic dev zone
NRF_TIMER0->SHORTS = (TIMER_SHORTS_COMPARE0_CLEAR_Enabled << TIMER_SHORTS_COMPARE0_CLEAR_Pos);
//attachInterrupt(TIMER1_IRQn, TIMER1_Interrupt); // also used in variant.cpp to configure the RTC1
NVIC_EnableIRQ(TIMER0_IRQn);
NRF_TIMER0->TASKS_START = 1; // Start TIMER
// digitalWrite(LED, HIGH);
// delay(3000);
//
}

void setup() {
Serial.begin(115200);
pinMode(LED,OUTPUT);
digitalWrite(LED, LOW);
delay(3000);
timer_config();
}

void loop() {
// digitalWrite(LED, LOW);
// delay(1000);
// digitalWrite(LED, HIGH);
// delay(1000);
// //digitalWrite(LED, HIGH);
// //digitalWrite(LED, HIGH);

//while(1);
}

void TIMER0_IRQHandler()
{
// digitalWrite(LED, LOW);
// delay(1000);
// digitalWrite(LED, HIGH);
// delay(1000);
if (NRF_TIMER0->EVENTS_COMPARE[0] != 0)
{
//Serial.println("Timer interrupt called");
NRF_TIMER0->EVENTS_COMPARE[0] = 0;
int i = i+1;
if(i%2 == 0)
{
digitalWrite(LED, LOW);
delay(1000);
}
else
{
digitalWrite(LED, HIGH );
delay(1000);
}

}
}

Hey this is my code for blinking an led using timer interrupt on nrf 52832board, there are no errors in the code but the code is not working as desired. The function TIMER_IRQHandler is not called during an interrupt.

can someone please help me to tackle this problem?

RE: Timer interrupts

aabb — Wed, 19 Feb 2014 20:11:58 GMT

Thanks All, I got an answer from the RFduino team. The Timer1 is 16bit and regardless of the BITMODE the CC[0] cannot exceed 16 bit value (2^16=65536), so to obtain a 1sec timer it's necessary to use another PRESCALER value and a compatible CC[0] one.

RE: Timer interrupts

Ole Morten — Tue, 18 Feb 2014 12:39:34 GMT

I don't currently have access to an RFDuino, but when rewriting this code as a regular nRF51 project, this seems to work correctly. I've attached the main.c I used.

I therefore think you're better off asking this question on the RFDuino forums or similar. Sorry for not being able to give you better help.

main.c

RE: Timer interrupts

RS — Mon, 17 Feb 2014 21:56:18 GMT

According to the PS, Timer1 is 8/16 bits, so you should try to change BITMODE.