2.5 Timer Driver

• System>CLKCTRL:

  • Clock Selection: Internal high-frequency oscillator

  • Oscillator Frequency Selection: 4 MHz system clock (default)

• System>Pins:

  • Pin Grid View: Select LED pin as output (Check the schematic for your board)

  • Pins: Rename Custom Name to "LED"

  • Pin Grid View: Select SWITCH pin as input (check the schematic for your board)

  • Pins: Rename Custom Name to "SW"

  • Enable Weak Pullup if needed

• Drivers>Timer:

  • Timer PLIB Selector: TCA0

  • Timer Enable: False

  • Interrupt Driven: True

  • Requested Period: 100 ms

• Drivers>TCA0:

  • Clock Select: System Clock/8

#include "mcc_generated_files/system/system.h"
#include <util/delay.h>

/*
 * Development Board: AVR128DA48 Curiosity Nano Board
 * MCC Configuration:
 *     CLKCTRL module: Clock Selection - Internal high-frequency oscillator, Oscillator Frequency Selection - 4 MHz system clock (default)
 *     Timer module: Timer PLIB Selector - TCA0, Timer Enable - False, Interrupt Driven - True, Requested Timer Period - 100 ms
 *     TCA0 module: Clock Select - System Clock/8, Timer_PeriodSet() API Range - [2 us - 131.072 ms] (read-only)
 *     Pins module: RC6 - GPIO Output, CustomName - LED
 *                  RC7 - GPIO Input, CustomName - SW, Pull Up - Enable 
 */

#define SW_PRESSED 0U             // Switch - Active Low
#define SW_NOT_PRESSED 1U 
#define DEBONCE_DELAY_MS 20U      // Depends on hardware

#define MS_TO_TICKS(ms) (((TCA0_CLOCK_FREQ * (ms)) / 1000UL) - 1UL)
#define LED_40_MS (MS_TO_TICKS(40UL))           
#define LED_80_MS (MS_TO_TICKS(80UL))

static const struct TIMER_INTERFACE *Timer = &Timer0;

bool SW_StateGet(void)
{
    bool status = SW_NOT_PRESSED;
    if(SW_PRESSED == SW_GetValue())
    {
        _delay_ms(DEBONCE_DELAY_MS);
        if(SW_PRESSED == SW_GetValue())
        {
            status = SW_PRESSED;
        }        
    }
    return status;
}

void Timer_FrequencyChange(void)
{
    static volatile bool changePeriod = false;
    Timer->Stop();
    
    uint32_t maxCount = Timer->MaxCountGet();
    uint32_t newPeriod = changePeriod ? LED_40_MS:LED_80_MS;
    
    if(maxCount > newPeriod)
    {      
        Timer->PeriodSet(newPeriod);
    }
    else
    {
        // Invalid period
    }
    changePeriod = !changePeriod;
    Timer->Start(); 
}

void Timer_Callback(void)
{
    LED_Toggle();
}

int main(void)
{
    SYSTEM_Initialize();

    Timer->PeriodSet(LED_40_MS);
    Timer->TimeoutCallbackRegister(Timer_Callback);
    Timer->Start();    
  
    // Enable the Global Interrupts 
    sei(); 
    
    while(1)
    {
        if(SW_PRESSED == SW_StateGet())
        {
            Timer_FrequencyChange();
        }
    }    
}

• System>CLKCTRL:

  • Clock Selection: Internal high-frequency oscillator

  • Oscillator Frequency Selection: 4 MHz system clock (default)

• System>Pins:

  • Pin Grid View: Select LED1 pin as output (Check the schematic for your board)

  • Pins: Rename Custom Name to "LED1"

  • Pin Grid View: Select LED2 pin as output (Check the schematic for your board)

  • Pins: Rename Custom Name to "LED2"

• Drivers>Timer:

  • Timer PLIB Selector: TCA0

  • Timer Enable: False

  • Interrupt Driven: True

  • Requested Period: 1 ms

#include "mcc_generated_files/system/system.h"

/*
 * Development Board: AVR128DA48 Curiosity Nano Board
 * MCC Configuration:
 *     CLKCTRL module: Clock Selection - Internal high-frequency oscillator, Oscillator Frequency Selection - 4 MHz system clock (default) 
 *     Timer module: Timer PLIB Selector - TCA0, Timer Enable - False, Interrupt Driven - True, Requested Timer Period - 1 ms
 *     Pins module: PC5, PC6 - GPIO Output, CustomName - PC5->LED1, PC6->LED2 
 */

static void Task_A_2ms(void)
{
    LED1_SetHigh();
    NOP();
    NOP();
    LED1_SetLow();
    
    // Add your code here. E.g., LED Toggle
}
static void Task_B_5ms(void)
{
    LED2_SetHigh();
    NOP();
    NOP();
    LED2_SetLow();  
    
    // Add your code here. E.g., Read Sensor
}

static void Tasks_Scheduler(void)
{
    static volatile uint8_t oneMs_tickCounter =  0;
    
    oneMs_tickCounter++;
            
    if((oneMs_tickCounter % 2U) == 0U)
    {
        Task_A_2ms();    // Run at 2 ms, 4 ms, 6 ms, 8 ms, and 10 ms.
    }
    
    if((oneMs_tickCounter % 5U) == 0U)
    {
        Task_B_5ms();    // Run at 5 ms and 10 ms.
    }
    if(oneMs_tickCounter == 10U)
    {
        oneMs_tickCounter = 0;
    }
}

int main(void)
{
    const struct TIMER_INTERFACE *Timer = &Timer0;

    SYSTEM_Initialize();
 
    Timer->TimeoutCallbackRegister(Tasks_Scheduler);
    Timer->Start();
    
    // Enable the Global Interrupts 
    sei(); 

    while(1)
    {
    }   
}

• System>CLKCTRL:

  • Clock Selection: Internal high-frequency oscillator

  • Oscillator Frequency Selection: 4 MHz system clock (default)

• System>Pins:

  • Pin Grid View: Select LED pin as output (Check the schematic for your board)

  • Pins: Rename Custom Name to "LED"

• Drivers>Timer:

  • Timer PLIB Selector: TCA0

  • Timer Enable: False

  • Interrupt Driven: True

  • Requested Period: 10 ms

#include "mcc_generated_files/system/system.h"

/*
 * Development Board: AVR128DA48 Curiosity Nano Board
 * MCC Configuration:
 *     CLKCTRL module: Clock Selection - Internal high-frequency oscillator, Oscillator Frequency Selection - 4 MHz system clock (default) (4 MHz)
 *     Timer module: Timer PLIB Selector - TCA0, Timer Enable - False, Interrupt Driven - True, Requested Timer Period - 10 ms 
 *     TCA0 module: Timer_PeriodSet() API Range - [250 ns - 16.384 ms] (read-only)
 *     Pins module: PC6 - GPIO Output, CustomName - LED 
 */
 
#define TIMER_TICK_FREQ TCA0_CLOCK_FREQ
#define MS_TO_TICKS(ms) (((TIMER_TICK_FREQ * (ms)) / 1000UL) - 1UL)
#define LED_4_MS MS_TO_TICKS(4UL)        // Set the period to be within the PeriodSet API range
#define LED_8_MS MS_TO_TICKS(8UL)

static const struct TIMER_INTERFACE *Timer = &Timer0;

static void Timer_PeriodChange(void)
{ 
    static volatile bool changePeriod = false;
    LED_Toggle();
    Timer->Stop();
    
    uint32_t maxCount = Timer->MaxCountGet();
    uint32_t newPeriod = changePeriod ? LED_4_MS : LED_8_MS;
    
    if(maxCount > newPeriod)
    {     
        Timer->PeriodSet(newPeriod);
    }
    else
    {
        // Invalid period       
    }
    
    changePeriod = !changePeriod;
    Timer->Start();
}


int main(void)
{
    SYSTEM_Initialize();
    
    Timer->PeriodSet(LED_4_MS);
    Timer->TimeoutCallbackRegister(Timer_PeriodChange);
    Timer->Start();
    
    // Enable the Global Interrupts 
    sei(); 
    
    while(1)
    {
    }    
}

• System>CLKCTRL:

  • Clock Selection: Internal high-frequency oscillator

  • Oscillator Frequency Selection: 4 MHz system clock (default)

• System>Pins:

  • Pin Grid View: Select LED pin as output (Check the schematic for your board)

  • Pins: Rename Custom Name to "LED"

• Drivers>Timer:

  • Timer PLIB Selector: TCA0

  • Timer Enable: False

  • Interrupt Driven: False

  • Requested Period: 500 ms

• Drivers>TCA0:

  • Clock Select: System Clock/64

#include "mcc_generated_files/system/system.h"

/*
 * Development Board: AVR128DA48 Curiosity Nano Board
 * MCC Configuration:
 *     CLKCTRL module: Clock Selection - Internal high-frequency oscillator, Oscillator Frequency Selection - 4 MHz system clock (default)
 *     Timer module: Timer PLIB Selector - TCA0, Timer Enable - False, Interrupt Driven - False, Requested Timer Period - 500 ms 
 *     TCA0 module: Clock Selection - System Clock/64
 *     Pins module: PC6 - GPIO Output, CustomName - LED 
 */

static void Timer_Callback(void)
{
    LED_Toggle();   
}

int main(void)
{
    SYSTEM_Initialize();

    Timer0.TimeoutCallbackRegister(Timer_Callback);
    Timer0.Start();
    while(1)
    {
        Timer0.Tasks();
    }    
}