main.c

/**********************************************************************************************************************
 * \file main.c
 * \copyright Copyright (C) Infineon Technologies AG 2019
 * 
 * Use of this file is subject to the terms of use agreed between (i) you or the company in which ordinary course of 
 * business you are acting and (ii) Infineon Technologies AG or its licensees. If and as long as no such terms of use
 * are agreed, use of this file is subject to following:
 * 
 * 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.
 *********************************************************************************************************************/
/*********************************************************************************************************************/
/*-----------------------------------------------------Includes------------------------------------------------------*/
/*********************************************************************************************************************/
#include "cy_pdl.h"
#include "cybsp.h"
#include "cy_retarget_io.h"
#include "cyhal.h"

/*********************************************************************************************************************/
/*------------------------------------------------------Macros-------------------------------------------------------*/
/*********************************************************************************************************************/
/* Result output format  */
enum OutputFmt
{
    UNSIGNED_RIGHT_ALIGNED,
    SIGNED_RIGHT_ALIGNED,
    LEFT_ALIGNED,
    FORMAT_NUM
};

/* Lower level of average count  */
#define AVERAGE_COUNT_MIN (1u)

/* Upper level of average count  */
#define AVERAGE_COUNT_MAX (256u)

/* Internal band gap reference voltage */
#define BAND_GAP_MV (900u)

/*********************************************************************************************************************/
/*-------------------------------------------------Global variables--------------------------------------------------*/
/*********************************************************************************************************************/
/* Interrupt configuration */
const cy_stc_sysint_t IRQ_CFG =
{
    .intrSrc = ((NvicMux3_IRQn << CY_SYSINT_INTRSRC_MUXIRQ_SHIFT) | CE_SAR2_CH1_IRQ),
    .intrPriority = 2UL
};

int32_t g_nextOutputFormat = UNSIGNED_RIGHT_ALIGNED;
int32_t g_nextAverageCount = 1;
int32_t g_outputFormat = -1;
int32_t g_averageCount = -1;

const char *OUTPUT_FORMAT_STR[FORMAT_NUM] =
{
    "Unsigned/Right Aligned",
    "Signed/Right Aligned  ",
    "Left Aligned          "
};

/*********************************************************************************************************************/
/*------------------------------------------------Function Prototypes------------------------------------------------*/
/*********************************************************************************************************************/
void handle_SAR_ADC_IRQ(void);
void configure_SAR_ADC(int32_t outputFormat, int32_t averageCount);

/*********************************************************************************************************************/
/*---------------------------------------------Function Implementations----------------------------------------------*/
/*********************************************************************************************************************/
/**********************************************************************************************************************
 * Function Name: main
 * Summary:
 *  This is the main function.
 *  It sets up SAR ADC with default setting then inputs software trigger to start AD conversion.
 *  The main while loop captures the command from terminal and stores the value to global variable.
 * Parameters:
 *  none
 * Return:
 *  int
 **********************************************************************************************************************
 */
int main(void)
{
    cy_rslt_t result;

#if defined (CY_DEVICE_SECURE)
    cyhal_wdt_t wdt_obj;

    /* Clear watchdog timer so that it doesn't trigger a reset */
    result = cyhal_wdt_init(&wdt_obj, cyhal_wdt_get_max_timeout_ms());
    CY_ASSERT(CY_RSLT_SUCCESS == result);
    cyhal_wdt_free(&wdt_obj);
#endif /* #if defined (CY_DEVICE_SECURE) */

    /* 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);
    }

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

    printf("****************** Code Example: SAR ADC Various Processing of Conversion Result ******************\r\n");
    printf("Press 'a' key to decrease the average count:\r\n"
           "    [256 -> 128 -> 64 -> 32 -> 16 -> 8 -> 4 -> 2 -> 1]\r\n"
           "Press 'd' key to increase the average count:\r\n"
           "    [1 -> 2 -> 4 -> 8 -> 16 -> 32 -> 64 -> 128 -> 256]\r\n"
           "Press 's' key to change the output format:\r\n"
           "    [(Unsigned/Right Aligned) -> (Signed/Right Aligned) -> (Left Aligned) -> (Unsigned/Right Aligned)...]\r\n\n");

    /* \x1b[?25l - ESC sequence for clear cursor (not a pure VT100 escape sequence, but it works in TeraTerm) */
    printf("\x1b[?25l");

    /* Configure SAR-ADC */
    configure_SAR_ADC(g_nextOutputFormat, g_nextAverageCount);

    for (;;)
    {
        uint8_t uartReadValue;

        /* Check if any of valid keys was pressed */
        if (cyhal_uart_getc(&cy_retarget_io_uart_obj, &uartReadValue, 1) == CY_RSLT_SUCCESS)
        {
            if ((uartReadValue == 'a') || (uartReadValue == 'd'))
            {
                /* Check for limits and increment/decrement accordingly */
                if ((uartReadValue == 'a') && (g_nextAverageCount != AVERAGE_COUNT_MIN))
                {
                    g_nextAverageCount >>= 1;
                }
                else if ((uartReadValue == 'd') && (g_nextAverageCount != AVERAGE_COUNT_MAX))
                {
                    g_nextAverageCount <<= 1;
                }
            }
            else if (uartReadValue == 's')
            {
                /* change the output format to next one */
                if (++g_nextOutputFormat > LEFT_ALIGNED)
                {
                    g_nextOutputFormat = UNSIGNED_RIGHT_ALIGNED;
                }
            }
        }
    }
}

/**********************************************************************************************************************
 * Function Name: handle_SAR_ADC_IRQ
 * Summary:
 *  SAR ADC interrupt handler function, will display the potentiometer voltage in milli volt.
 *  Then it reconfigures SAR ADC according to the value of global variable if changes are there.
 * Parameters:
 *  none
 * Return:
 *  none
 **********************************************************************************************************************
 */
void handle_SAR_ADC_IRQ(void)
{
    /* Get interrupt source */
    uint32_t intr = Cy_SAR2_Channel_GetInterruptStatus(PASS0_SAR0, CE_SAR2_AN0_IDX);

    /* Clear interrupt source */
    Cy_SAR2_Channel_ClearInterrupt(PASS0_SAR0, CE_SAR2_AN0_IDX, intr);

    /* if the interrupt is group-done */
    if (intr == CY_SAR2_INT_GRP_DONE)
    {
        /* Get conversion results in counts, do not obtain or analyze status here */
        uint16_t resultVBG = Cy_SAR2_Channel_GetResult(PASS0_SAR0, CE_SAR2_VBG_IDX, NULL);
        uint16_t resultAN0_raw = Cy_SAR2_Channel_GetResult(PASS0_SAR0, CE_SAR2_AN0_IDX, NULL);
        uint16_t resultAN0 = resultAN0_raw;

        if (g_outputFormat == SIGNED_RIGHT_ALIGNED)
        {
            resultAN0 = (resultAN0_raw & 0xFFF);

            /* The 12-bit code for a signal at VREFH/2 is 0x800.
             * This means 0x800 is considered 0, any value below 0x800 is on considered negative,
             * and values above 0x800 are considered positive
             */
            if ((resultAN0 & 0x800) != 0)
            {
                resultAN0 -= 0x800;
            }
            else
            {
                resultAN0 += 0x800;
            }
        }
        else if (g_outputFormat == LEFT_ALIGNED)
        {
            resultAN0 = (resultAN0_raw >> 4) & 0xFFF;
        }

        /* Update the current configuration and the conversion result then move cursor to previous line */
        printf("Output format: %s\r\nAverage count: %3ld\r\n", OUTPUT_FORMAT_STR[g_outputFormat], g_averageCount);
        printf("Conversion result raw value: 0x%04x\r\n", resultAN0_raw);
        printf("Potentiometer voltage: %4ldmV\r\n", ((uint32_t)resultAN0 * BAND_GAP_MV) / (uint32_t)resultVBG);
        printf("\x1b[4F");

        configure_SAR_ADC(g_nextOutputFormat, g_nextAverageCount);
    }
}

/**********************************************************************************************************************
 * Function Name: configure_SAR_ADC
 * Summary:
 *  This function configures SAR ADC with specified setting.
 * Parameters:
 *  int32_t outputFormat - The received output format from user input
 *  int32_t averageCount - The received average count from user input
 * Return:
 *  none
 **********************************************************************************************************************
 */
void configure_SAR_ADC(int32_t outputFormat, int32_t averageCount)
{
    if ((g_outputFormat != outputFormat) || (g_averageCount != averageCount))
    {
        /* De-initialize the SAR2 module */
        Cy_SAR2_DeInit(PASS0_SAR0);

        /* Reflect specified configuration into the structure value */
        CE_SAR2_AN0_config.rightShift = log(averageCount) / log(2);
        CE_SAR2_AN0_config.averageCount = (uint16_t)averageCount;

        if (outputFormat == UNSIGNED_RIGHT_ALIGNED)
        {
            CE_SAR2_AN0_config.resultAlignment = CY_SAR2_RESULT_ALIGNMENT_RIGHT;
            CE_SAR2_AN0_config.signExtention = CY_SAR2_SIGN_EXTENTION_UNSIGNED;
        }
        else if (outputFormat == SIGNED_RIGHT_ALIGNED)
        {
            CE_SAR2_AN0_config.resultAlignment = CY_SAR2_RESULT_ALIGNMENT_RIGHT;
            CE_SAR2_AN0_config.signExtention = CY_SAR2_SIGN_EXTENTION_SIGNED;
        }
        else
        {
            CE_SAR2_AN0_config.resultAlignment = CY_SAR2_RESULT_ALIGNMENT_LEFT;
            CE_SAR2_AN0_config.signExtention = CY_SAR2_SIGN_EXTENTION_UNSIGNED;
        }

        /* Initialize the SAR2 module */
        Cy_SAR2_Init(PASS0_SAR0, &CE_SAR2_config);

        /* Set ePASS MMIO reference buffer mode for bangap voltage */
        Cy_SAR2_SetReferenceBufferMode(PASS0_EPASS_MMIO, CY_SAR2_REF_BUF_MODE_ON);

        /* Interrupt settings */
        Cy_SAR2_Channel_SetInterruptMask(PASS0_SAR0, CE_SAR2_AN0_IDX, CY_SAR2_INT_GRP_DONE);
        Cy_SysInt_Init(&IRQ_CFG, &handle_SAR_ADC_IRQ);
        NVIC_SetPriority((IRQn_Type) NvicMux3_IRQn, 2UL);
        NVIC_EnableIRQ((IRQn_Type) NvicMux3_IRQn);
    }

    /* Update current configuration */
    g_outputFormat = outputFormat;
    g_averageCount = averageCount;

    /* Scenario: Obtaining conversion results in counts */
    Cy_SAR2_Channel_SoftwareTrigger(PASS0_SAR0, CE_SAR2_VBG_IDX);
}
/* [] END OF FILE */