PIC32MZ tutorial -- Blinky LED

　　Today I finish the "Blinky LED" application on PIC32MZ starter kit. This application let LED1 blink with 0.5HZ frequency. The pseudo code is like

LOOP:

LED ON

Delay 1 second

LED OFF

Delay 1 second

　　It uses Timer1 to control the delay time. So first I implement the three Timer1 functions.

/**

Function: TMR1_Open

Summary: Initialization of Timer

Description: TMR1 on; 0.08 microsecond every tick

Remarks: Pre-scale 1:8; PB 100MHz; PR1 0xFFFF

*/

void TMR1_Open(void)

{

T1CON = 0x8010;

PR1 = 0xFFFF;

}

// Comment a function definition and leverage automatic documentation

/**

Function: TMR1_Write

Summary: Write TMR1

Description: Write a value to TMR1

Remarks: the value is range of 0~65535

*/

void TMR1_Write(unsigned int value)

{

TMR1 = value & 0xFFFF;

}

/**

Function: TMR1_Read

Summary: Read TMR1

Description: Read the value from TMR1

Remarks: the value is range of 0~65535

*/

unsigned int TMR1_Read(void)

{

return (TMR1 & 0xFFFF);

}

　　Second I finish the delay function, the implemention is like below

/**

Function: Delay_1S

Summary: Delay using TMR1

Description: Delay one second

Remarks: call TMR1_Open first

*/

void Delay_1S(void)

{

unsigned int count = 12500;

unsigned int ticks = 1000;

while (count--)

{

TMR1_Write(0);

while (TMR1_Read() < ticks)

{

; // do nothing

}

}

}

　　Actually we are also able to do that like below

/**

Function: Delay_1S

Summary: Delay using TMR1

Description: Delay one second

Remarks: call TMR1_Open first

*/

void Delay_1S(void)

{

unsigned int count = 1000;

unsigned int ticks = 12500;

while (count--)

{

TMR1_Write(0);

while (TMR1_Read() < ticks)

{

; // do nothing

}

}

}

　　I prefer to the second one. I believe the second one has higher accuracy than the first one.

　　In the end, I finish the main function. In last blog, I already show how to implement LED_SETON. This time, we will the same LED_SETON funtion, and more, we need to implement LED_SETOFF. That's easy once you have read my last blog. If you don't know yet, please look at below.

#include

#include "Delay.h"

#include "ConfigurationBits.h"

#define LED_IOCTL() TRISHCLR = (1<<0)

#define LED_SETON() LATHSET = (1<<0)

#define LED_SETOFF() LATHCLR = (1<<0)

#define LED_OPEN() ANSELH &= 0xFFFFFFFE

void main(void)

{

TMR1_Open();

LED_OPEN();

LED_IOCTL();

while (1)

{

LED_SETON();

Delay_1S();

LED_SETOFF();

Delay_1S();

}

}