main.c

/******************************************************************************
* File Name:   main.c
*
* Description: This is the source code for the CYW43907 Hello World Example
*              for ModusToolbox.
*
* Related Document: See README.md
*
*
*******************************************************************************
* $ Copyright 2021-2023 Cypress Semiconductor $
*******************************************************************************/

#include "cyhal.h"
#include "cybsp.h"
#include "cy_retarget_io.h"

/*******************************************************************************
* Macros
********************************************************************************/

/* LED blink timer clock value in Hz.  */
#define LED_BLINK_TIMER_CLOCK_HZ          (5000)

/* LED blink timer period value */
#define LED_BLINK_TIMER_PERIOD            (20000)


/*******************************************************************************
* Function Prototypes
*******************************************************************************/
void timer_init(void);
static void isr_timer(void *callback_arg, cyhal_timer_event_t event);


/*******************************************************************************
* Global Variables
*******************************************************************************/
bool timer_interrupt_flag = false;
bool led_blink_active_flag = true;

/* Variable for storing character read from terminal */
uint8_t uart_read_value;

/* Timer object used for blinking the LED */
cyhal_timer_t led_blink_timer;


/*******************************************************************************
* Function Name: main
********************************************************************************
* Summary:
* This is the main function for CYW43907 CPU. It does
*    1. UART console output
*    2. LED Blinking with timer ISR
*
* Parameters:
*  void
*
* Return:
*  int
*
*******************************************************************************/
int main(void)
{
    cy_rslt_t result;

    /* Initialize the device and board peripherals */
    result = cybsp_init();
    
    /* Board init failed. Stop program execution */
    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }


    /* Enable global interrupts */
    __enable_irq();

    /* Initialize retarget-io to use the debug UART port */
    result = cy_retarget_io_init(CYBSP_DEBUG_UART_TX, CYBSP_DEBUG_UART_RX,
                                 CY_RETARGET_IO_BAUDRATE);

    /* retarget-io init failed. Stop program execution */
    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* Initialize the User LED */
    result = cyhal_gpio_init(CYBSP_LED2, CYHAL_GPIO_DIR_OUTPUT,
                             CYHAL_GPIO_DRIVE_STRONG, CYBSP_LED_STATE_OFF);

    /* GPIO init failed. Stop program execution */
    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* \x1b[2J\x1b[;H - ANSI ESC sequence for clear screen */
    printf("\x1b[2J\x1b[;H");

    printf("****************** "
           "CYW43907 Hello World"
           "****************** \r\n\n");

    /* Initialize timer to toggle the LED */
    timer_init();
 
    printf("Press 'Enter' key to pause or "
           "resume blinking the user LED \r\n\r\n");

    for (;;)
    {
        /* Check if 'Enter' key was pressed */
        if (cyhal_uart_getc(&cy_retarget_io_uart_obj, &uart_read_value, 1) 
             == CY_RSLT_SUCCESS)
        {
            if (uart_read_value == '\r')
            {
                /* Pause LED blinking by stopping the timer */
                if (led_blink_active_flag)
                {
                    cyhal_timer_stop(&led_blink_timer);

                    printf("LED blinking paused \r\n");
                }
                else /* Resume LED blinking by starting the timer */
                {
                    cyhal_timer_start(&led_blink_timer);

                    printf("LED blinking resumed\r\n");
                }

                /* Move cursor to previous line */
                printf("\x1b[1F");

                led_blink_active_flag ^= 1;
            }
        }

        /* Check if timer elapsed (interrupt fired) and toggle the LED */
        if (timer_interrupt_flag)
        {
            /* Clear the flag */
            timer_interrupt_flag = false;

            /* Invert the USER LED state */
            cyhal_gpio_toggle(CYBSP_LED2);
        }
    }
}


/*******************************************************************************
* Function Name: timer_init
********************************************************************************
* Summary:
* This function creates and configures a Timer object. The timer ticks 
* continuously and produces a periodic interrupt on every terminal count 
* event. The period is defined by the 'period' and 'compare_value' of the 
* timer configuration structure 'led_blink_timer_cfg'. Without any changes, 
* this application is designed to produce an interrupt every 1 second.
*
* Parameters:
*  none
*
*******************************************************************************/
 void timer_init(void)
 {
    cy_rslt_t result;

    const cyhal_timer_cfg_t led_blink_timer_cfg = 
    {
        .compare_value = 19999,                 /* Timer compare value, not used */
        .period = LED_BLINK_TIMER_PERIOD,   /* Defines the timer period */
        .direction = CYHAL_TIMER_DIR_UP,    /* Timer counts up */
        .is_compare = true,                /* Don't use compare mode */
        .is_continuous = true,              /* Run timer indefinitely */
        .value = 0                          /* Initial value of counter */
    };

    /* Initialize the timer object. Does not use input pin ('pin' is NC) and
     * does not use a pre-configured clock source ('clk' is NULL). */
    result = cyhal_timer_init(&led_blink_timer, NC, NULL);

    /* timer init failed. Stop program execution */
    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* Configure timer period and operation mode such as count direction, 
       duration. */
    result= cyhal_timer_configure(&led_blink_timer, &led_blink_timer_cfg);

    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* Set the frequency of timer's clock source */
    result =cyhal_timer_set_frequency(&led_blink_timer, 10000);

    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* Assign the ISR to execute on timer interrupt */
    cyhal_timer_register_callback(&led_blink_timer, isr_timer, NULL);

    /* Set the event on which timer interrupt occurs and enable it */
    cyhal_timer_enable_event(&led_blink_timer, CYHAL_TIMER_IRQ_TERMINAL_COUNT,
                              3, true);

    /* Start the timer with the configured settings */
    result=cyhal_timer_start(&led_blink_timer);

    if(result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

 }


/*******************************************************************************
* Function Name: isr_timer
********************************************************************************
* Summary:
* This is the interrupt handler function for the timer interrupt.
*
* Parameters:
*    callback_arg    Arguments passed to the interrupt callback
*    event            Timer/counter interrupt triggers
*
*******************************************************************************/
static void isr_timer(void *callback_arg, cyhal_timer_event_t event)
{
    (void) callback_arg;
    (void) event;
    /* Set the interrupt flag and process it from the main while(1) loop */
    timer_interrupt_flag = true;
}

/* [] END OF FILE */