main.c

/******************************************************************************
* File Name: main.c
*
* Description: This is the source code for the PSoC 4 HVMS 128K MSC CapSense CSX Button
* Tuning code example for ModusToolbox.
*
* Related Document: See README.md
*
*******************************************************************************
* Copyright 2021-2024, Cypress Semiconductor Corporation (an Infineon company) or
* an affiliate of Cypress Semiconductor Corporation.  All rights reserved.
*
* This software, including source code, documentation and related
* materials ("Software") is owned by Cypress Semiconductor Corporation
* or one of its affiliates ("Cypress") and is protected by and subject to
* worldwide patent protection (United States and foreign),
* United States copyright laws and international treaty provisions.
* Therefore, you may use this Software only as provided in the license
* agreement accompanying the software package from which you
* obtained this Software ("EULA").
* If no EULA applies, Cypress hereby grants you a personal, non-exclusive,
* non-transferable license to copy, modify, and compile the Software
* source code solely for use in connection with Cypress's
* integrated circuit products.  Any reproduction, modification, translation,
* compilation, or representation of this Software except as specified
* above is prohibited without the express written permission of Cypress.
*
* Disclaimer: THIS SOFTWARE IS PROVIDED AS-IS, WITH NO WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, NONINFRINGEMENT, IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress
* reserves the right to make changes to the Software without notice. Cypress
* does not assume any liability arising out of the application or use of the
* Software or any product or circuit described in the Software. Cypress does
* not authorize its products for use in any products where a malfunction or
* failure of the Cypress product may reasonably be expected to result in
* significant property damage, injury or death ("High Risk Product"). By
* including Cypress's product in a High Risk Product, the manufacturer
* of such system or application assumes all risk of such use and in doing
* so agrees to indemnify Cypress against all liability.
*******************************************************************************/


/*******************************************************************************
 * Include header files
 ******************************************************************************/
#include "cy_pdl.h"
#include "cybsp.h"
#include "cycfg.h"
#include "cycfg_capsense.h"


/*******************************************************************************
* Macros
*******************************************************************************/
#define CAPSENSE_MSC0_INTR_PRIORITY      (3u)
#define CY_ASSERT_FAILED                 (0u)
#define MSC_CAPSENSE_WIDGET_INACTIVE     (0u)

/* CapSense tuner interface settings */
#define TUNER_UART						(1u) // Enabling CapSense Tuner with UART
#define TUNER_I2C						(2u) // Enabling CapSense Tuner with I2C
#define TUNER_PROTOCOL					TUNER_UART // Selecting Tuner interface

/*******************************************************************************
* Global Variables
********************************************************************************/
#if(TUNER_PROTOCOL == TUNER_I2C)
	/* I2C tuner interrupt priority must be higher than CapSense interrupt. */
	#define EZI2C_INTR_PRIORITY              (2u)
	cy_stc_scb_ezi2c_context_t i2c_context;
#else
	/* Uart tuner interrupt priority must be higher than CapSense interrupt. */
	#define UART_INTR_PRIORITY              (2u)

	cy_stc_scb_uart_context_t CYBSP_UART_context;
	/* Define UART ring buffer size to hold extra tuner command packets.
	    *  Additional byte is required by the UART ring buffer implementation.
	    */
	#define UART_RINGBUFFER_SIZE (CY_CAPSENSE_COMMAND_PACKET_SIZE * 2u + 1u)
#endif /*TUNER PROTOCOL SELECTION*/

#if CY_CAPSENSE_BIST_EN
/* Variables to hold electrode parasitic capacitances */
uint32_t tx0_cp = 0, tx1_cp = 0, rx0_cp = 0, rx1_cp = 0;
cy_en_capsense_bist_status_t tx0_cp_status, tx1_cp_status, rx0_cp_status, rx1_cp_status;
#endif /* CY_CAPSENSE_BIST_EN */


/*******************************************************************************
* Function Prototypes
*******************************************************************************/
static void initialize_capsense(void);
static void capsense_msc0_isr(void);
static void initialize_capsense_tuner(void);
static void tuner_isr(void);

static void led_control(void);

#if CY_CAPSENSE_BIST_EN
static void measure_sensor_cp(void);
#endif /* CY_CAPSENSE_BIST_EN */

#if(TUNER_PROTOCOL == TUNER_UART)

void tuner_send(void * context);
void tuner_receive(uint8_t ** packet, uint8_t ** tunerPacket, void * context);

#endif /* TUNER_UART */

/*******************************************************************************
* Function Name: main
********************************************************************************
* Summary:
*  System entrance point. This function performs
*  - initial setup of device
*  - initialize CapSense
*  - perform Cp measurement if Built-in Self test (BIST) is enabled
*  - initialize tuner communication
*  - scan touch input continuously
*
* Return:
*  int
*
*******************************************************************************/
int main(void)
{
    cy_rslt_t result = CY_RSLT_SUCCESS;

    /* Initialize the device and board peripherals */
    result = cybsp_init();

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

    /* Initialize the CapSense Tuner */
    initialize_capsense_tuner();

    /* Enable global interrupts */
    __enable_irq();

    /* Initialize MSC CapSense */
    initialize_capsense();

    /* Delay to allow the device to receive the command from the Tuner Tool.
    *  The delay time depends on the CAPSENSE™ configuration
    *  and the device initialization time.
    */
    Cy_SysLib_Delay(100u);

    /* Process first received command, if available */
    (void)Cy_CapSense_RunTuner(&cy_capsense_context);

#if CY_CAPSENSE_BIST_EN
    /* Measure the self capacitance of tx and rx electrodes using BIST */
    measure_sensor_cp();
#endif /* CY_CAPSENSE_BIST_EN */

    /* Start the first scan */
    Cy_CapSense_ScanAllSlots(&cy_capsense_context);

    for (;;)
    {
        if(CY_CAPSENSE_NOT_BUSY == Cy_CapSense_IsBusy(&cy_capsense_context))
        {
            /* Process all widgets */
            Cy_CapSense_ProcessAllWidgets(&cy_capsense_context);

            /* Turns LED ON/OFF based on button status */
            led_control();

            /* Establishes synchronized communication with the CapSense Tuner tool */
            Cy_CapSense_RunTuner(&cy_capsense_context);

            /* Start the next scan */
            Cy_CapSense_ScanAllSlots(&cy_capsense_context);
        }
    }
}


/*******************************************************************************
* Function Name: initialize_capsense
********************************************************************************
* Summary:
*  This function initializes the CapSense and configures the CapSense
*  interrupt.
*
*******************************************************************************/
static void initialize_capsense(void)
{
    cy_capsense_status_t status = CY_CAPSENSE_STATUS_SUCCESS;

    /* CapSense interrupt configuration MSC 0 */
    const cy_stc_sysint_t capsense_msc0_interrupt_config =
    {
        .intrSrc = CY_MSC0_IRQ,
        .intrPriority = CAPSENSE_MSC0_INTR_PRIORITY,
    };

    /* Capture the MSC HW block and initialize it to the default state. */
    status = Cy_CapSense_Init(&cy_capsense_context);

    if (CY_CAPSENSE_STATUS_SUCCESS == status)
    {
        /* Initialize CapSense interrupt for MSC 0 */
        Cy_SysInt_Init(&capsense_msc0_interrupt_config, capsense_msc0_isr);
        NVIC_ClearPendingIRQ(capsense_msc0_interrupt_config.intrSrc);
        NVIC_EnableIRQ(capsense_msc0_interrupt_config.intrSrc);

        /* Initialize the CapSense firmware modules. */
        status = Cy_CapSense_Enable(&cy_capsense_context);
    }

#if(TUNER_PROTOCOL == TUNER_UART)
	/* Register communication callbacks for UART*/
	cy_capsense_context.ptrInternalContext->ptrTunerSendCallback = tuner_send;
	cy_capsense_context.ptrInternalContext->ptrTunerReceiveCallback = tuner_receive;
#endif /*TUNER_UART*/

    if(status != CY_CAPSENSE_STATUS_SUCCESS)
    {
        /* This status could fail before tuning the sensors correctly.
         * Ensure that this function passes after the CapSense sensors are tuned
         * as per procedure give in the Readme.md file */
    }
}

/*******************************************************************************
* Function Name: capsense_msc0_isr
********************************************************************************
* Summary:
*  Wrapper function for handling interrupts from CapSense MSC0 block.
*
*******************************************************************************/
static void capsense_msc0_isr(void)
{
    Cy_CapSense_InterruptHandler(msc_0_msc_0_HW, &cy_capsense_context);
}


/*******************************************************************************
* Function Name: initialize_capsense_tuner
********************************************************************************
* Summary:
* UART or I2C module to communicate with the CapSense Tuner tool.
*
*******************************************************************************/
static void initialize_capsense_tuner(void)
{
#if(TUNER_PROTOCOL == TUNER_I2C)

    cy_en_scb_ezi2c_status_t status = CY_SCB_EZI2C_SUCCESS;

    /* EZI2C interrupt configuration structure */
    const cy_stc_sysint_t i2c_intr_config =
    {
        .intrSrc = CYBSP_EZI2C_IRQ,
        .intrPriority = EZI2C_INTR_PRIORITY,
    };

    /* Initialize the EzI2C firmware module */
    status = Cy_SCB_EZI2C_Init(CYBSP_EZI2C_HW, &CYBSP_EZI2C_config, &i2c_context);

    if(status != CY_SCB_EZI2C_SUCCESS)
    {
        CY_ASSERT(CY_ASSERT_FAILED);
    }

    Cy_SysInt_Init(&i2c_intr_config, tuner_isr);
    NVIC_EnableIRQ(i2c_intr_config.intrSrc);

    /* Set the CapSense data structure as the I2C buffer to be exposed to the
     * master on primary slave address interface. Any I2C host tools such as
     * the Tuner or the Bridge Control Panel can read this buffer but you can
     * connect only one tool at a time.
     */
    Cy_SCB_EZI2C_SetBuffer1(CYBSP_EZI2C_HW, (uint8_t *)&cy_capsense_tuner,
                            sizeof(cy_capsense_tuner), sizeof(cy_capsense_tuner),
                            &i2c_context);

    Cy_SCB_EZI2C_Enable(CYBSP_EZI2C_HW);

#else

    static uint8_t uartRingBuffer[UART_RINGBUFFER_SIZE];
    cy_en_scb_uart_status_t initstatus;

    /* UART interrupt configuration structure */
    const cy_stc_sysint_t uart_intr_config =
    {
    	.intrSrc = scb_1_IRQ,
    	.intrPriority = UART_INTR_PRIORITY,
    };

    /* Configure and enable UART communication */
    initstatus = Cy_SCB_UART_Init(scb_1_HW, &scb_1_config, &CYBSP_UART_context);

    if(initstatus != CY_SCB_UART_SUCCESS)
    {
        CY_ASSERT(CY_ASSERT_FAILED);
    }

    Cy_SysInt_Init(&uart_intr_config, tuner_isr);
    NVIC_EnableIRQ(uart_intr_config.intrSrc);

    Cy_SCB_UART_StartRingBuffer(scb_1_HW, uartRingBuffer, UART_RINGBUFFER_SIZE, &CYBSP_UART_context);

    Cy_SCB_UART_Enable(scb_1_HW);
#endif /*TUNER PROTOCOL SELECTION*/
}

/*******************************************************************************
* Function Name: led_control
********************************************************************************
* Summary:
* Turning LED ON/OFF based on button status
*
*******************************************************************************/
static void led_control(void)
{
    if(MSC_CAPSENSE_WIDGET_INACTIVE != Cy_CapSense_IsWidgetActive(CY_CAPSENSE_BUTTON0_WDGT_ID, &cy_capsense_context))
    {
        Cy_GPIO_Write(CYBSP_LED_BTN1_PORT, CYBSP_LED_BTN1_NUM, CYBSP_LED_STATE_OFF);
    }
    else
    {
        Cy_GPIO_Write(CYBSP_LED_BTN1_PORT, CYBSP_LED_BTN1_NUM, CYBSP_LED_STATE_ON);
    }

    if(MSC_CAPSENSE_WIDGET_INACTIVE != Cy_CapSense_IsWidgetActive(CY_CAPSENSE_BUTTON1_WDGT_ID, &cy_capsense_context))
    {
        Cy_GPIO_Write(CYBSP_LED_BTN0_PORT, CYBSP_LED_BTN0_NUM, CYBSP_LED_STATE_OFF);
    }
    else
    {
        Cy_GPIO_Write(CYBSP_LED_BTN0_PORT, CYBSP_LED_BTN0_NUM, CYBSP_LED_STATE_ON);
    }
}

/*******************************************************************************
* Function Name: tuner_isr
********************************************************************************
* Summary:
* Wrapper function for handling interrupts from I2C or UART block.
*
*******************************************************************************/
static void tuner_isr(void)
{
#if(TUNER_PROTOCOL == TUNER_I2C)
	Cy_SCB_EZI2C_Interrupt(CYBSP_I2C_HW, &i2c_context);
#else
	Cy_SCB_UART_Interrupt(scb_1_HW, &CYBSP_UART_context);
#endif /*TUNER PROTOCOL SELECTION*/
}

#if(TUNER_PROTOCOL == TUNER_UART)
/*******************************************************************************
* Function Name: tuner_send
********************************************************************************
* Summary:
* Tuner send callback function for UART block
*
*******************************************************************************/
void tuner_send(void * context)
{
	uint8_t uartTxHeader[] = {0x0Du, 0x0Au};
	uint8_t uartTxTail[] = {0x00u, 0xFFu, 0xFFu};
	(void)context;
	Cy_SCB_UART_PutArrayBlocking(scb_1_HW, &(uartTxHeader[0u]), sizeof(uartTxHeader));
	Cy_SCB_UART_PutArrayBlocking(scb_1_HW, (uint8_t *)&cy_capsense_tuner, sizeof(cy_capsense_tuner));
	Cy_SCB_UART_PutArrayBlocking(scb_1_HW, &(uartTxTail[0u]), sizeof(uartTxTail));
	/* Blocking wait for transfer completion */
	while (!Cy_SCB_UART_IsTxComplete(scb_1_HW))
	{
	}
}

/*******************************************************************************
* Function Name: tuner_receive
********************************************************************************
* Summary:
* Tuner received callback function for UART block
*
*******************************************************************************/
void tuner_receive(uint8_t ** packet, uint8_t ** tunerPacket, void * context)
{
	uint32_t i;
	(void)context;
	static uint32_t dataIndex = 0u;
	static uint8_t commandPacket[CY_CAPSENSE_COMMAND_PACKET_SIZE] = {0u};
	uint32_t numBytes;
	while(0u != Cy_SCB_UART_GetNumInRingBuffer(scb_1_HW, &CYBSP_UART_context))
	{
		numBytes = Cy_SCB_UART_GetNumInRingBuffer(scb_1_HW, &CYBSP_UART_context);
		/* Calculate number of bytes to read from ring buffer */
		if ((CY_CAPSENSE_COMMAND_PACKET_SIZE - dataIndex) < numBytes)
		{
			numBytes = CY_CAPSENSE_COMMAND_PACKET_SIZE - dataIndex;
		}
		/* Add received data to the end of commandPacket */
		Cy_SCB_UART_Receive(scb_1_HW, &commandPacket[dataIndex], numBytes, &CYBSP_UART_context);
		dataIndex += numBytes;
		if(CY_CAPSENSE_COMMAND_PACKET_SIZE <= dataIndex)
		{
			if (CY_CAPSENSE_COMMAND_OK == Cy_CapSense_CheckTunerCmdIntegrity(&commandPacket[0u]))
			{
				/* Found a correct command, reset data index and assign pointers to buffers */
				dataIndex = 0u;
				*tunerPacket = (uint8_t *)&cy_capsense_tuner;
				*packet = &commandPacket[0u];
				break;
			}
			else
			{
				/* Command is not correct, remove the first byte in commandPacket buffer */
				dataIndex--;
				for (i = 0u; i < (CY_CAPSENSE_COMMAND_PACKET_SIZE - 1u); i++)
				{
					commandPacket[i] = commandPacket[i + 1u];
				}
			}
		}
	}
}

#endif /* TUNER_UART */

#if CY_CAPSENSE_BIST_EN
/*******************************************************************************
* Function Name: measure_sensor_cp
********************************************************************************
* Summary:
*  Measures the self capacitance of Tx and Rx electrodes in Femto Farads and
*  store its value.
*
*******************************************************************************/
static void measure_sensor_cp(void)
{
    /* Measure the self capacitance of Tx 0 electrode */
    tx0_cp_status = Cy_CapSense_MeasureCapacitanceSensorElectrode(CY_CAPSENSE_BUTTON0_WDGT_ID,
                                                  CY_CAPSENSE_BUTTON0_TX0_ID, &cy_capsense_context);
    tx0_cp = cy_capsense_context.ptrWdConfig[CY_CAPSENSE_BUTTON0_WDGT_ID].ptrEltdCapacitance[CY_CAPSENSE_BUTTON0_TX0_ID];

    /* Measure the self capacitance of Rx 0 electrode */
    rx0_cp_status = Cy_CapSense_MeasureCapacitanceSensorElectrode(CY_CAPSENSE_BUTTON0_WDGT_ID,
                                                  CY_CAPSENSE_BUTTON0_RX0_ID, &cy_capsense_context);
    rx0_cp = cy_capsense_context.ptrWdConfig[CY_CAPSENSE_BUTTON0_WDGT_ID].ptrEltdCapacitance[CY_CAPSENSE_BUTTON0_RX0_ID];

    /* Measure the self capacitance of Tx 1 electrode */
    tx1_cp_status = Cy_CapSense_MeasureCapacitanceSensorElectrode(CY_CAPSENSE_BUTTON1_WDGT_ID,
                                                  CY_CAPSENSE_BUTTON1_TX0_ID, &cy_capsense_context);
    tx1_cp = cy_capsense_context.ptrWdConfig[CY_CAPSENSE_BUTTON1_WDGT_ID].ptrEltdCapacitance[CY_CAPSENSE_BUTTON1_TX0_ID];

    /* Measure the self capacitance of Rx 1 electrode */
    rx1_cp_status = Cy_CapSense_MeasureCapacitanceSensorElectrode(CY_CAPSENSE_BUTTON1_WDGT_ID,
                                                  CY_CAPSENSE_BUTTON1_RX0_ID, &cy_capsense_context);
    rx1_cp = cy_capsense_context.ptrWdConfig[CY_CAPSENSE_BUTTON1_WDGT_ID].ptrEltdCapacitance[CY_CAPSENSE_BUTTON1_RX0_ID];
}
#endif /* CY_CAPSENSE_BIST_EN */

/* [] END OF FILE */