main.c

/******************************************************************************
* File Name:   main.c
*
* Description: This is the source code for the XMC MCU: DAC Sine Example
*              for ModusToolbox. This example demonstrate two of five DAC
*              configurations. It generates an analog sine wave on DAC0
*              Output and a static analog value on DAC1 Output. The frequency
*              and time duration of the sine waves are adjusted to play a melody
*              out of the DAC0 output.
*
* Related Document: See README.md
*
******************************************************************************
*
* Copyright (c) 2015-2022, Infineon Technologies AG
* All rights reserved.
*
* Boost Software License - Version 1.0 - August 17th, 2003
*
* Permission is hereby granted, free of charge, to any person or organization
* obtaining a copy of the software and accompanying documentation covered by
* this license (the "Software") to use, reproduce, display, distribute,
* execute, and transmit the Software, and to prepare derivative works of the
* Software, and to permit third-parties to whom the Software is furnished to
* do so, all subject to the following:
*
* The copyright notices in the Software and this entire statement, including
* the above license grant, this restriction and the following disclaimer,
* must be included in all copies of the Software, in whole or in part, and
* all derivative works of the Software, unless such copies or derivative
* works are solely in the form of machine-executable object code generated by
* a source language processor.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
* SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
* FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
*****************************************************************************/

#include "cybsp.h"
#include "cy_utils.h"
#include "cy_retarget_io.h"

/*******************************************************************************
* Defines
*******************************************************************************/

#define R                   (20000U)        /* Frequency outside the audible range */
#define ARRAY_SIZE          (48U)           /* Size of the arrays for melody frequency and beat size */
#define TICKS_PER_SECOND    (100U)          /* Systick ticks per second */
#define SINE_CHANNEL        (0U)            /*DAC channel for sine output*/
#define STATIC_CHANNEL      (1U)            /*DAC channel for static output*/

/* Define macro to enable/disable printing of debug messages */
#define ENABLE_XMC_DEBUG_PRINT (0)

/* Define macro to set the loop count before printing debug messages */
#if ENABLE_XMC_DEBUG_PRINT
static bool DAC_updated = false;
static bool loop_entered = false;
#endif

/*******************************************************************************
* Global Variables
*******************************************************************************/
/*
 * The values in melody[index] defines the new frequency. Frequencies defined by R
 * are outside audible range and act as pauses in the melody being played.
 */
const uint16_t melody[ARRAY_SIZE] =
{
  660U, R,  660U,   R,  660U,   R,  510U,   R,
  660U, R,  770U,   R,  380U,   R,  510U,   R,
  380U, R,  320U,   R,  440U,   R,  480U,   R,
  450U, R,  430U,   R,  380U,   R,  660U,   R,
  760U, R,  860U,   R,  700U,   R,  760U,   R,
  660U, R,  520U,   R,  580U,   R,  480U,   R
};

/*
 * The value in beats[index] defines the number of function calls
 * after which the frequency will be updated. This defines the duration
 * and pause times in the melody being played
 */
const uint16_t beats[ARRAY_SIZE] =
{
  10U, 15U, 10U, 30U, 10U, 30U, 10U, 10U,
  10U, 30U, 10U, 55U, 10U, 57U, 10U, 45U,
  10U, 40U, 10U, 50U, 10U, 30U,  8U, 33U,
  10U, 15U, 10U, 30U, 10U, 20U,  8U, 20U,
  5U,  15U, 10U, 30U,  8U, 15U,  5U, 35U,
  8U,  30U,  8U, 15U,  8U, 15U,  8U, 50U
};

/*******************************************************************************
* Function Prototypes
*******************************************************************************/
void DacUpdate(void);

/*******************************************************************************
* Function Name: SysTick_Handler
********************************************************************************
* Summary:
* Handler for Systick interrupt. To change the frequency  of the sine wave,
* function DAC_Update() is called periodically. The sine wave generation is
* taken care by the DAC module and do not require any periodic function calls.
* DAC_Update() has to be called only to change frequency of basic sine wave
* generated.
*
* Parameters:
*  void
*
* Return:
*  void
*
*******************************************************************************/
void SysTick_Handler(void)
{
    DacUpdate();
}

/*******************************************************************************
* Function Name: main
********************************************************************************
* Summary
* This is the main function. Initializes both DAC channels. Sets DAC0 in pattern
* mode and DAC1 in single value mode. Systick timer is also configured, which will
* take care of the frequency update of the pattern being generated.
*
* Parameters:
*  none
*
* Return:
*  int
*
*******************************************************************************/
int main(void)
{
    cy_rslt_t result;

    /* Initialize the device and board peripherals */
    result = cybsp_init();
    if (result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    cy_retarget_io_init(CYBSP_DEBUG_UART_HW);

    #if ENABLE_XMC_DEBUG_PRINT
    printf("Initialization done\r\n");
    #endif

    /* System timer configuration */
    SysTick_Config(SystemCoreClock / TICKS_PER_SECOND);
    while (1)
    {
        #if ENABLE_XMC_DEBUG_PRINT
        if(DAC_updated)
        {
            if(!loop_entered)
            {
                printf("DAC Updated\r\n");
                loop_entered = true;
            }
        }
        #endif
    }
}

/*******************************************************************************
* Function Name: DacUpdate
********************************************************************************
* Summary:
* Updates the DAC frequency after beats[index] function calls.
* New frequency value is melody[index]. Each frequncy value in melody[index] denote
* a musical note to be played. Value in beats[index] determines the duration for which
* each note is being played.
*
* e.g.:
*   index=0, beats[index]= 10, melody[index] =660 and Dac_Update is called after 10ms:
*   Sine wave with 660Hz will be displayed for 100ms.
*
*
* If melody[index] =R, frequency is shifted out of audible area. Corresponding values
* in beats[index] determines the pause duration in the melody being played .
*
* Parameters:
*  none
*
* Return:
*  none
*******************************************************************************/
void DacUpdate(void)
{
    /* Variable to track function call limit */
    static uint8_t function_calls = 0;
    /* Index variable to track and update frequency */
    static uint8_t index = 0;

    /* Increment function call count */
    function_calls++;

    /* check if function_call limit is reached.*/
    if (function_calls >= beats[index])
    {
        function_calls = 0;
        /* Increment index value for new frequency */
        index++;

        /* avoid array overflow.*/
        if (index >= ARRAY_SIZE)
        {
            index = 0;
        }
        /* update frequency */
        XMC_DAC_CH_SetPatternFrequency(XMC_DAC0, SINE_CHANNEL, melody[index]);
    #if ENABLE_XMC_DEBUG_PRINT
    DAC_updated = true;
    #endif
    }
}
/* [] END OF FILE */