Energia - Timer based blink

startup_gcc.c diff

$ diff linux/work/hardware/lm4f/cores/lm4f/startup_gcc.c ../hardware/lm4f/cores/lm4f/startup_gcc.c 
71d70
< __attribute__((weak)) extern void Timer0IntHandler(void) {}
123c122
<     Timer0IntHandler,                      // Timer 0 subtimer A
---
>     IntDefaultHandler,                      // Timer 0 subtimer A
$ 

timer_blink.c

/*
 * timer_blink - C API
 */
 
#include "Energia.h"
#include "inc/hw_ints.h"
#include "driverlib/interrupt.h"
#include "driverlib/sysctl.h"
#include "driverlib/timer.h"
#include "timer_blink.h"

void initTimer(unsigned Hz)
{
  //GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);
  SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
  TimerConfigure(TIMER0_BASE, TIMER_CFG_32_BIT_PER);
  unsigned long ulPeriod = (SysCtlClockGet() / Hz) / 2;
  TimerLoadSet(TIMER0_BASE, TIMER_A, ulPeriod -1);
  IntEnable(INT_TIMER0A);
  TimerIntEnable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
  TimerEnable(TIMER0_BASE, TIMER_A);
}

void Timer0IntHandler()
{
  // Clear the timer interrupt
  TimerIntClear(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
  
  // Read the current state of the GPIO pin and
  // write back the opposite state
  if(GPIOPinRead(GPIO_PORTF_BASE, GPIO_PIN_2)) {
    GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, 0);
  }
  else {
    GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 4);
  }
}

timer_blink.h

#ifdef __cplusplus
extern "C" {
#endif

void initTimer(unsigned);
void Timer0IntHandler(void);

#ifdef __cplusplus
}
#endif

timer_blink.ino

/**
 * LM4F120 - timer based blink
 */

#include "timer_blink.h"

static const unsigned Hz=3; 

void setup()
{    
  pinMode(BLUE_LED,OUTPUT);
  initTimer(Hz); 
}

void loop()
{
}