Create a Project

Create a new project and select the PIC16F1619 along with the Curiosity board and MPLAB XC8.

Launch MCC

Open MCC under the Tools > Embedded menu of MPLAB X IDE.

System Setup

From Project Resources, choose System Module to open the System Setup window within MCC.

1. In the clock settings, make sure you select INTOSC.
2. Select the system clock FOSC.
3. Set Internal Clock to 4MHz_HF setting.
4. Check the PLL Enabled box.
5. The Curiosity board uses a Programmer/Debugger On-Board (PKOB) and uses a low voltage program method to program the MCU. Therefore, the low voltage programming must be enabled by checking the Low-voltage programming Enable box.

Timer4 Setup

Add the TMR4 peripheral to the project from the Device Resources area of MCC. To do that, scroll down to the timer entry and expand the list by clicking on the arrow. Now, double click on the TMR4 entry to add it to the Project Resources list. Then, click on TMR4 to open the Timer4 configuration setup screen.

1. Check the Enable Timer box.
2. Select Clock Source FOSC/4, Postscaler 1:1, and Prescaler 1:64.
3. Set Timer Period value to 9.088 ms.
4. Set External Reset Source to T4IN and Control Mode to Roll over pulse.
5. Set Start/Reset Option to Software Control (this will inhibit hardware reset of timer).
6. Check the Enable Timer Interrupt box.

To extend the Timer4 based delay, software overflows will use a callback function. The overflow of TMR4 will trigger an interrupt and the MCC generated TMR4 driver code will count up to the Callback Function Rate (CFR) value of events, before calling a predefined interrupt function that will then implement the ISR in the main.c file (that will be created in step 7).

To configure the callback value, enter "11" in the CFR field. This will give us about a 100 ms rate (11 × 9.088 ms = 99.968 ms).

Pin Module Setup

Click on Pin Module in the Project Resources area. This will open up the Pin Module and the Pin Management Grid. Click on the RC5 Output row blue lock to turn it green.

Rename the I/O pin

In the Pin Module, rename the pin RC5 to "IO_LED_D7". Only the Output box should be checked.

Generate Driver Code

Click on Generate under Project Resources to have the MCC create the drivers and a base main.c file for the project.

main.c

The main.c file needs to be updated to handle the callback function using the function pointers generated by the MCC drivers. The function pointers allow main.c to handle all operations without having to modify the driver code.

The first modification is to add void myTimer4ISR(void); right after the #include mcc_generated_files/mcc.h.

#include "mcc_generated_files/mcc.h"

void myTimer4ISR(void);

This defines the name of the ISR that will be created to control the LED.

Now, the Timer4 driver default Interrupt Handler has to be connected to the ISR defined in main.c.. This is handled by adding the line TMR4_SetInterruptHandler (myTimer4ISR);, right after the SYSTEM_Initialize function.

// initialize the device
    SYSTEM_Initialize();

    TMR4_SetInterruptHandler (myTimer4ISR);  //Define interrupt Handler

Remove the double backslash comment markers from Global and Peripheral Interrupt Enable functions:
// INTERRUPT_GlobalInterruptEnable();
// INTERRUPT_PeripheralInterruptEnable();
This action will include a call to the predefined macros and enable interrupts.

// Enable the Global Interrupts
    INTERRUPT_GlobalInterruptEnable();

// Enable the Peripheral Interrupts
    INTERRUPT_PeripheralInterruptEnable();

Finally, define what the ISR does when the number of callbacks is complete and the interrupt is processed. For this, a macro that was created in the MCC generated pin_manager.h file is used. The macro selected will toggle the LED from off to on and on to off on each ISR call. Add the myTimer4ISR ISR after the while(1) loop. This will complete the modifications to main.c required for this project.

    while (1)
    {
        // Add your application code
    }

}
void myTimer4ISR(void){
    IO_LED_D7_Toggle(); //Control LED
}
/**
 End of File
*/

Build Project

Click on Build Project icon to compile the code and you will see a "BUILD SUCCESSFUL" message in the Output window of MPLAB X within several seconds of processing time.

BUILD SUCCESSFUL (total time: 8s)

Make sure your Curiosity board is connected to the USB port. Then, click on the Make and Program Device icon. This will build the project again and launch the programmer built into the Curiosity board. In the Output window, you should see a series of messages and when successful, it will end with a "Programming and Verify Successful" message.

Output Window:

Connecting to MPLAB Starter Kit on Board...

Currently loaded firmware on Starter Kit on Board
Firmware Suite Version.....01.41.07
Firmware type..............Enhanced Midrange

Target detected
Device ID Revision = 2004

The following memory area(s) will be programmed:
program memory: start address = 0x0, end address = 0xbf
configuration memory

Programming...
Programming/Verify complete