ATY_LIB/MAX31865_ATY.c

/**
* @file MAX31865_ATY.c
*
* @param Project DEVICE_DRIVER_ATY_LIB
*
* @author ATY
*
* @copyright
*       - Copyright 2017 - 2026 MZ-ATY
*       - This code follows:
*           - MZ-ATY Various Contents Joint Statement -
*               <a href="https://mengze.top/MZ-ATY_VCJS">
*                        https://mengze.top/MZ-ATY_VCJS</a>
*           - CC 4.0 BY-NC-SA -
*               <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">
*                        https://creativecommons.org/licenses/by-nc-sa/4.0/</a>
*       - Your use will be deemed to have accepted the terms of this statement.
*
* @brief functions of MAX31865 platinum resistance temperature detector for C platform
*
* @note SPI_POLARITY_HIGH + SPI_PHASE_2EDGE = CPOL=1, CPHA=1 = SPI Mode 3
*
* @version
*       - 1_01_251216 > ATY
*           -# Preliminary version, first Release
* @todo MAX31865_CONFIG_FAULTCTR and MAX31865_REG_H/LFAULT_M/LSB
********************************************************************************
*/

#ifndef __MAX31865_ATY_C
#define __MAX31865_ATY_C

#include "MAX31865_ATY.h"
#define MAX31865_ATY_TAG "\r\n[MAX31865_ATY] "

/******************************* For user *************************************/

/******************************************************************************/

uint8_t wrData[2] = {0x00, 0x00};

/**
 * @brief   Initialize MAX31865 device
 *
 * @param   dev Device structure pointer
 * @return  uint8_t Execution result
 */
uint8_t MAX31865_Init(struct MAX31865_ATY_Dev* dev){
    __ATY_LOCK(dev);

    if(dev->initFlag == 0){
        // Set default parameters for PT100 sensor
        if(dev->rtdNominal == 0)
            dev->rtdNominal = 100.0;
        if(dev->refResistor == 0)
            dev->refResistor = 430.0;

        // Configuration register settings
        wrData[0] = MAX31865_REG_CONFIG | 0x80;
        wrData[1] = 0;

        if(dev->filter50Hz == 1){
            wrData[1] |= MAX31865_CONFIG_FILT50HZ;
        }
        if(dev->rtdWires == 3){
            wrData[1] |= MAX31865_CONFIG_3WIRE;
        }
        if(dev->autoConvert == 1){
            wrData[1] |= MAX31865_CONFIG_MODEAUTO;
        }
        if(dev->bias == 1){
            wrData[1] |= MAX31865_CONFIG_BIAS;
        }

        // Write to configuration register
        dev->nssSet(__ATY_HL_L);
        dev->spiProcess(wrData, 2, __ATY_RW_W);
        dev->nssSet(__ATY_HL_H);

        dev->initFlag = 1;

        __ATY_UNLOCK(dev);
        printf_ATY_D("%sInit config: 0x%02X",
            MAX31865_ATY_TAG, wrData[1]);
        MAX31865_ReadConfig(dev);
        __ATY_LOCK(dev);
    }
    __ATY_UNLOCK(dev);
    return 0;
}

/**
 * @brief   Read configuration register
 *
 * @param   dev Device structure pointer
 * @return  uint8_t Configuration register value
 */
uint8_t MAX31865_ReadConfig(struct MAX31865_ATY_Dev* dev){
    __ATY_LOCK(dev);

    wrData[0] = MAX31865_REG_CONFIG;

    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData, 2, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    printf_ATY_D("%sRead config: 0x%02X",
        MAX31865_ATY_TAG, wrData[0]);

    __ATY_UNLOCK(dev);
    return wrData[0];
}

/**
 * @brief   Read raw RTD value
 *
 * @param   dev Device structure pointer
 * @param   rtd Pointer to store RTD value
 * @return  uint8_t Execution result
 */
uint8_t MAX31865_ReadRTD(struct MAX31865_ATY_Dev* dev){
    MAX31865_Init(dev);

    __ATY_LOCK(dev);

    wrData[0] = MAX31865_REG_RTD_MSB;
    wrData[1] = 0;

    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData, 2, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    // remove last fault bit
    dev->rtdValue = ((wrData[0] << 8) | wrData[1]) >> 1;

    __ATY_UNLOCK(dev);
    return 0;
}

/**
 * @brief   Read fault status
 *
 * @param   dev Device structure pointer
 * @return  uint8_t Fault status register value
 */
uint8_t MAX31865_ReadFault(struct MAX31865_ATY_Dev* dev){
    __ATY_LOCK(dev);

    dev->faultStatus = 0;
    wrData[0] = MAX31865_REG_FAULT_STATUS;

    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData, 1, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    dev->faultStatus = wrData[0];

    if(dev->faultStatus != 0){
        printf_ATY_D("%sFault: 0x%02X", MAX31865_ATY_TAG, dev->faultStatus);
        if(dev->faultStatus & MAX31865_FAULT_HIGH_THRESH){
            printf_ATY_D(" HIGH_THRESHOLD");
        }
        if(dev->faultStatus & MAX31865_FAULT_LOW_THRESH){
            printf_ATY_D(" LOW_THRESHOLD");
        }
        if(dev->faultStatus & MAX31865_FAULT_REFIN_LOW){
            printf_ATY_D(" REFIN_LOW");
        }
        if(dev->faultStatus & MAX31865_FAULT_REFIN_HIGH){
            printf_ATY_D(" REFIN_HIGH");
        }
        if(dev->faultStatus & MAX31865_FAULT_RTDIN_LOW){
            printf_ATY_D(" RTDIN_LOW");
        }
        if(dev->faultStatus & MAX31865_FAULT_OVUV){
            printf_ATY_D(" OVER_UNDER_VOLTAGE");
        }
    }

    __ATY_UNLOCK(dev);
    return wrData[0];
}

/**
 * @brief   Clear fault status
 *
 * @param   dev Device structure pointer
 * @return  uint8_t Execution result
 */
uint8_t MAX31865_ClearFaults(struct MAX31865_ATY_Dev* dev){
    __ATY_LOCK(dev);

    dev->faultStatus = 0;
    wrData[0] = MAX31865_REG_CONFIG;

    // Read current configuration
    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData, 1, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    // Set fault clear bit
    wrData[1] = wrData[0];
    wrData[1] |= MAX31865_CONFIG_FAULTSTAT;
    // printf_ATY_D("\r\n0x%02X", wrData[0]);
    // printf_ATY_D("\r\n0x%02X", wrData[1]);
    wrData[0] = MAX31865_REG_CONFIG | 0x80;

    // Write back to configuration register
    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData + 1, 1, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    __ATY_UNLOCK(dev);
    return 0;
}

/**
 * @brief   Trigger one-shot conversion
 *
 * @param   dev Device structure pointer
 * @return  uint8_t Execution result
 */
uint8_t MAX31865_OneShot(struct MAX31865_ATY_Dev* dev){
    MAX31865_Init(dev);

    __ATY_LOCK(dev);

    wrData[0] = MAX31865_REG_CONFIG;

    // Read current configuration
    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData, 1, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    wrData[1] = wrData[0];
    wrData[1] |= MAX31865_CONFIG_1SHOT;
    wrData[0] = MAX31865_REG_CONFIG | 0x80;

    // Write back to configuration register
    dev->nssSet(__ATY_HL_L);
    dev->spiProcess(wrData, 1, __ATY_RW_W);
    dev->spiProcess(wrData + 1, 1, __ATY_RW_R);
    dev->nssSet(__ATY_HL_H);

    __ATY_UNLOCK(dev);
    return 0;
}


/**
 * @brief   Calculate resistance from RTD value
 *
 * @param   dev Device structure pointer
 * @param   rtd RTD value, if 0, use internal RTD value
 * @return  float Resistance
 */
float MAX31865_CalculateResistance(struct MAX31865_ATY_Dev* dev, uint16_t rtd){
    if(rtd == 0)
        return (float)dev->rtdValue * dev->refResistor / ((uint16_t)1 << 15);
    return (float)rtd * dev->refResistor / ((uint16_t)1 << 15);
}

/**
 * @brief   Calculate temperature from RTD value
 *
 * @param   dev Device structure pointer
 * @param   rtd RTD value, if 0, use internal RTD value
 * @return  float Temperature
 */
float MAX31865_CalculateTemperature(struct MAX31865_ATY_Dev* dev, uint16_t rtd){
    return (MAX31865_CalculateResistance(dev, rtd) - dev->rtdNominal) / 0.385;
}


#endif /* __MAX31865_ATY_C */

/************************************ etc *************************************/
/* init
// MAX31865 --------------------------------------------------------------------
#include "MAX31865_ATY.h"
void MAX31865_1_NSS_SET(uint8_t level){
    if(level == __ATY_HL_L)
        HAL_GPIO_WritePin(SPI2_NSS_GPIO_Port, SPI2_NSS_Pin, GPIO_PIN_RESET);
    else if(level == __ATY_HL_H)
        HAL_GPIO_WritePin(SPI2_NSS_GPIO_Port, SPI2_NSS_Pin, GPIO_PIN_SET);
}
uint8_t MAX31865_1_SPI(uint8_t* data_t, uint16_t len, uint8_t rw){
    if(rw == __ATY_RW_R){
        return HAL_SPI_Receive(&hspi2, (uint8_t*)data_t, len, 1000);
    }
    else{
        return HAL_SPI_Transmit(&hspi2, (uint8_t*)data_t, len, 1000);
    }
}
struct MAX31865_ATY_Dev MAX31865_ATY_Dev_1 = {
    .nssSet = MAX31865_1_NSS_SET,
    .spiProcess = MAX31865_1_SPI,
    .initFlag = 0,

    .bias = 1,
    .autoConvert = 1,
    .rtdWires = 3,
    .faultControl = 0,
    .filter50Hz = 1,

    .rtdNominal = 100.0,
    .refResistor = 424.0,

    .rtdValue = 0,
    .faultStatus = 0,

    .lock = __ATY_UNLOCKED
};
*/

/* use
uint8_t Max31865_errCount = 0;
void MAX31865_Test(void){
    MAX31865_ReadRTD(&MAX31865_ATY_Dev_1);
    MAX31865_ReadFault(&MAX31865_ATY_Dev_1);

    // (9584640.0 / MAX31865_ATY_Dev_1.refResistor) -> 500C
    // (2015232.0 / MAX31865_ATY_Dev_1.refResistor) -> -100C
    if(MAX31865_ATY_Dev_1.faultStatus != 0
        || MAX31865_ATY_Dev_1.rtdValue == 32767
        || MAX31865_ATY_Dev_1.rtdValue == 0
        || MAX31865_ATY_Dev_1.rtdValue > (9584640.0 / MAX31865_ATY_Dev_1.refResistor)
        || MAX31865_ATY_Dev_1.rtdValue < (2015232.0 / MAX31865_ATY_Dev_1.refResistor)){
        Max31865_errCount++;
        // if cycle is long like 1s, this errCount can be lower
        if(Max31865_errCount > 6){
            Max31865_errCount = 0;
            MAX31865_ATY_Dev_1.initFlag = 0;
            // Notice: ClearFaults might make next rtd value wrong,
            // so wait a cycle to read value after clear fault
            if(MAX31865_ATY_Dev_1.faultStatus != 0) MAX31865_ClearFaults(&MAX31865_ATY_Dev_1);
            printf_ATY("\r\nRTD Value Abnormal - Reinitializing...");
        }
    }
    // else
    {
        printf_ATY("\r\nRTD: 0x%04X, Resistance: %.2f ohm, Temperature: %.2f C",
            MAX31865_ATY_Dev_1.rtdValue,
            MAX31865_CalculateResistance(&MAX31865_ATY_Dev_1, 0),
            MAX31865_CalculateTemperature(&MAX31865_ATY_Dev_1, 0));
        // MAX31865_ReadConfig(&MAX31865_ATY_Dev_1);
    }
}
*/

/******************************************************************************/


/******************************** End Of File *********************************/