Timer & Pin Interrupts for TIVA

[TVG 0]

I have experience with the traditional C programming in Code Composer and have implemented a timer interrupt routine in CCS for TIVA TM4C1294, now I want to create a timer ISR in Energia, how do I proceed ?

[L.R.A 78]

The same way. If you set the ISR in the startup then in Energia the difference is that you need to use TimerIntRegister() function.

There isn't any function in Energia to do this. (I've been wanting to make a library but too much too study or I simply forget)

[TVG 0]

Can you please provide a simple example?

 

Thanks @L.R.A

[energia 485]

Below is a simple example using 2 timers to toggle 2 LED's.

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/rom_map.h"
#include "driverlib/rom.h"
#include "driverlib/sysctl.h"
#include "driverlib/timer.h"

uint8_t greenLedState = HIGH;
uint8_t redLedState = LOW;

void setup()
{
  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  
  MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);  
  MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);
  MAP_TimerConfigure(TIMER0_BASE, TIMER_CFG_PERIODIC);
  MAP_TimerConfigure(TIMER1_BASE, TIMER_CFG_PERIODIC);

  MAP_TimerLoadSet(TIMER0_BASE, TIMER_A, MAP_SysCtlClockGet());
  MAP_TimerLoadSet(TIMER1_BASE, TIMER_A, MAP_SysCtlClockGet() / 10);

  TimerIntRegister(TIMER0_BASE, TIMER_A, &Timer0IntHandler);
  TimerIntRegister(TIMER1_BASE, TIMER_A, &Timer1IntHandler);
  
  MAP_TimerIntEnable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
  MAP_TimerIntEnable(TIMER1_BASE, TIMER_TIMA_TIMEOUT);
  
  MAP_TimerEnable(TIMER0_BASE, TIMER_A);
  MAP_TimerEnable(TIMER1_BASE, TIMER_A);
}

void loop()
{
  // Nothing to do 
}

void Timer0IntHandler() {
  MAP_TimerIntClear(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
  digitalWrite(GREEN_LED, greenLedState);
  greenLedState = !greenLedState;
}

void Timer1IntHandler() {
  MAP_TimerIntClear(TIMER1_BASE, TIMER_TIMA_TIMEOUT);
  digitalWrite(RED_LED, redLedState);
  redLedState = !redLedState;
}

[TVG 0]

In the above code, the LEDs blink perfectly, however when I use Serial.println("xyz"); in void loop() , the LEDs blink abruptly in between. @@energia

[energia 485]

Do not have a TivaC to try right now but you might want to try to insert a slight delay of 100ms in the loop.

 

Robert

[spirilis 1,265]

In the above code, the LEDs blink perfectly, however when I use Serial.println("xyz"); in void loop() , the LEDs blink abruptly in between. @@energia

Can you post your whole sketch?  I'm not seeing that... I added Serial.begin(115200) at the very top of setup and Serial.println("xyz"); inside loop.  Still seeing the LEDs blink similarly.

[energia 485]

I just now gave it a try as well and I too see the LED's flashing as expected.

You still might want to add a delay(100) or something in your loop to prevent the Serial monitor from being flooded.

 

Robert

[L.R.A 78]

Tested it at 9600 and 115200 and no visible issue. Maybe there are microseconds timing issues but not much else

 

[DanielYoo 0]

Add below 2 lines to above example code for function declaration.

And then work correctly

 

void Timer0IntHandler();

void Timer1IntHandler();