max31723.h

00001 /*******************************************************************************
00002 * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved.
00003 *
00004 * Permission is hereby granted, free of charge, to any person obtaining a
00005 * copy of this software and associated documentation files (the "Software"),
00006 * to deal in the Software without restriction, including without limitation
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00008 * and/or sell copies of the Software, and to permit persons to whom the
00009 * Software is furnished to do so, subject to the following conditions:
00010 *
00011 * The above copyright notice and this permission notice shall be included
00012 * in all copies or substantial portions of the Software.
00013 *
00014 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
00015 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00016 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
00017 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
00018 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
00019 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
00020 * OTHER DEALINGS IN THE SOFTWARE.
00021 *
00022 * Except as contained in this notice, the name of Maxim Integrated
00023 * Products, Inc. shall not be used except as stated in the Maxim Integrated
00024 * Products, Inc. Branding Policy.
00025 *
00026 * The mere transfer of this software does not imply any licenses
00027 * of trade secrets, proprietary technology, copyrights, patents,
00028 * trademarks, maskwork rights, or any other form of intellectual
00029 * property whatsoever. Maxim Integrated Products, Inc. retains all
00030 * ownership rights.
00031 *******************************************************************************
00032 * @file MAX31723.h
00033 *******************************************************************************
00034 */
00035 #ifndef MAX31723_H
00036 #define MAX31723_H
00037 
00038 #include "mbed.h"
00039 
00040 #define MAX31723_NO_ERROR   0
00041 #define MAX31723_ERROR      -1
00042 
00043 #define MAX31723_WRITE_MASK             0x80
00044 
00045 #define MAX31723_REG_CFG                0x00
00046 #define MAX31723_REG_TEMP_LSB           0x01
00047 #define MAX31723_REG_TEMP_MSB           0x02
00048 #define MAX31723_REG_TRIP_HI_LSB        0x03
00049 #define MAX31723_REG_TRIP_HI_MSB        0x04
00050 #define MAX31723_REG_TRIP_LO_LSB        0x05
00051 #define MAX31723_REG_TRIP_LO_MSB        0x06
00052 #define MAX31723_REG_MAX                MAX31723_REG_TRIP_LO_MSB
00053 
00054 /* Configuration, Status masks */
00055 #define MAX31723_CFG_CONTINUOUS         0x00
00056 #define MAX31723_CFG_STANDBY            0x01
00057 
00058 #define MAX31723_CFG_RESOLUTION_9BIT    0x00
00059 #define MAX31723_CFG_RESOLUTION_10BIT   0x02
00060 #define MAX31723_CFG_RESOLUTION_11BIT   0x04
00061 #define MAX31723_CFG_RESOLUTION_12BIT   0x06
00062 #define MAX31723_CFG_RESOLUTION_MASK    0x06
00063 
00064 #define MAX31723_CFG_TM_MODE_INTERRUPT  0x08
00065 #define MAX31723_CFG_1SHOT              0x10
00066 #define MAX31723_CFG_NVB_NVRAM_BUSY     0x20
00067 #define MAX31723_CFG_MEMW_CFG_WR_EEPROM 0x40
00068 
00069 #define MAX31723_CONV_TIME_MSEC_9BIT    0.025
00070 #define MAX31723_CONV_TIME_MSEC_10BIT   0.050
00071 #define MAX31723_CONV_TIME_MSEC_11BIT   0.100
00072 #define MAX31723_CONV_TIME_MSEC_12BIT   0.200
00073 
00074 #define MAX31723_NVRAM_WRITE_TIME_MSEC  0.015
00075 
00076 #define MAX31723_CF_LSB                 (0.00390625f)
00077 
00078 /**
00079  * @brief 9-bit to 12bit device temperature sensor with digital-to-analog converters (DACs)
00080  *        for the MAX31723.
00081  * @version 1.0000.0004
00082  *
00083  * @details The MAX31722/MAX31723 provides device temperature readings
00084  * for thermostats and thermometers. Communications may be either SPI or
00085  * 3-wire. There are two operating modes available: comparator or interrupt.
00086  * Temperature limits may be stored in NVRAM so that the TOUT_N pin can be 
00087  * triggered when the limits are exceeded while in the comparator mode.
00088  * Typically applications are for temperature sensitive systems.
00089  *
00090  * @code 
00091  * #include "mbed.h"
00092  * #include "max32630fthr.h"
00093  * #include "max31723.h"
00094  * #include "USBSerial.h"
00095  * 
00096  * MAX32630FTHR pegasus(MAX32630FTHR::VIO_1V8); 
00097  * 
00098  * DigitalOut gLED(LED2);
00099  * 
00100  * DigitalOut selectPin(P3_0);
00101  * SPI spi(P5_1, P5_2, P5_0);
00102  * 
00103  * int main()
00104  * {
00105  *     int i, ret;
00106  *     float temperature;
00107  *     DigitalOut gLED(LED2, LED_OFF);
00108  *     printf("MAX31723 Temperature Sensor example code.\r\n");
00109  *     printf("\r\n");
00110  *     
00111  *     gLED = LED_ON;
00112  * 
00113  *     MAX31723 temp_sensor(spi, selectPin);
00114  *     spi.format(8,3);
00115  *     spi.frequency(5000000);
00116  *     ret = temp_sensor.perform_one_shot_int(MAX31723_CFG_RESOLUTION_12BIT);
00117  *     
00118  *     for (i = 0; i < 5; i++) {
00119  *         ret = temp_sensor.perform_one_shot_int(MAX31723_CFG_RESOLUTION_12BIT);
00120  *         wait(MAX31723_CONV_TIME_MSEC_12BIT);
00121  *         temperature = temp_sensor.read_temperature();
00122  *         printf("Temperature = %4.4f Celsius, %4.4f Fahrenheit\r\n", 
00123  *             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
00124  *         wait(2);
00125  *     } 
00126  *     printf("Configuration Register = 0x%02Xh \r\n", temp_sensor.read_cfg());
00127  * }
00128  * 
00129  */
00130 
00131 class MAX31723{
00132     public:
00133     
00134     /**************************************************************
00135     * @brief Constructor for MAX31723 Class.  
00136     * 
00137     * @details Requires an existing SPI object as well as a DigitalOut object. 
00138     * The DigitalOut object is used for a chip enable signal
00139     *
00140     * On Entry:
00141     *     @param[in] spi - pointer to existing SPI object
00142     *     @param[in] ce_pin - pointer to a DigitalOut pin object
00143     *
00144     * On Exit:
00145     *
00146     * @return None
00147     ***************************************************************
00148     */
00149     MAX31723(SPI &spi, DigitalOut &ce_pin); 
00150 
00151     /** 
00152      * @brief Reads the register
00153      * @param &val - register value
00154      * @param reg  - address of the register
00155      * @return 0 on success, negative number on failure
00156      */
00157     int read_reg(uint8_t &val, uint8_t reg);
00158 
00159     /** 
00160      * @brief Reads the configuration register
00161      * @return value of the configuration register
00162      */
00163     uint8_t read_cfg();
00164 
00165     /** 
00166      * @brief Reads the temperature register
00167      * @return temperature in degrees Celsius
00168      */
00169     float read_temperature(void);
00170 
00171     /** 
00172      * @brief Reads the trip low temperature register
00173      * @return trip low temperature in degrees Celsius
00174      */
00175     float read_trip_low(void);
00176 
00177     /** 
00178      * @brief Reads the trip high temperature register
00179      * @return trip high temperature in degrees Celsius
00180      */
00181     float read_trip_high(void);
00182     
00183     /** 
00184      * @brief Writes to the configuration register
00185      * @param val - the configuration value
00186      * @return 0 on success, negative number on failure
00187      */
00188     int write_cfg(uint8_t val);
00189 
00190     /** 
00191      * @brief Writes to the Tlow register (the write takes 30 msec)
00192      * @param temperature - the temperature in Celsius degrees
00193      * @return 0 on success, negative number on failure
00194      */
00195      int write_trip_low(float temperature);
00196 
00197     /** 
00198      * @brief Writes to the Thigh register (the write takes 30 msec)
00199      * @param temperature - the temperature in Celsius degrees
00200      * @return 0 on success, negative number on failure
00201      */
00202      int write_trip_high(float temperature);
00203 
00204     /** 
00205      * @brief Reads the temperature registers
00206      * @param reg - the address of the temperature register
00207      * @return temprature in degrees Celsius
00208      */
00209     float read_reg_as_temperature(uint8_t reg);
00210 
00211     /** 
00212      * @brief Configures the device to perform a one-shot temperature reading
00213      *        and places the device in standby mode, interrupt mode.
00214      * @param resolution - the resolution of the calculation is set to this
00215      * @return 0 on success, negative number on failure
00216      */
00217     int perform_one_shot_int(uint8_t resolution);
00218 
00219     /** 
00220      * @brief Configures the device to perform a one-shot temperature reading
00221      *        and places the device in standby mode, comparator mode.
00222      * @param resolution - the resolution of the calculation is set to this
00223      * @return 0 on success, negative number on failure
00224      */
00225     int perform_one_shot_comparator(uint8_t resolution);
00226 
00227     /** 
00228      * @brief Converts Celcius degrees to Fahrenheit
00229      * @param temp_c - the temperature in Celsius degrees
00230      * @return 0 on success, negative number on failure
00231      */
00232     float celsius_to_fahrenheit(float temp_c);
00233 
00234     /************************************************************
00235      * @brief Default destructor for MAX31723 Class.  
00236      *
00237      * @details Destroys SPI object if owner 
00238      *
00239      * On Entry:
00240      *
00241      * On Exit:
00242      *
00243      * @return None
00244      *************************************************************
00245      */
00246     ~MAX31723();
00247 
00248     protected:
00249     /** 
00250      * @brief Configures the device to perform a one-shot temperature reading
00251      *        and places the device in standby mode, interrupt mode.
00252      * @param resolution - the resolution of the calculation is set to this
00253      * @return 0 on success, negative number on failure
00254      */
00255     int perform_one_shot(uint8_t resolution, uint8_t interrupt_mode);
00256 
00257     private:
00258     /** 
00259      * @brief Write a value to a register
00260      * @param val - 8-bit value to write to the register
00261      * @param reg - register address
00262      * @return 0 on success, negative number on failure
00263      */
00264     int write_reg(uint8_t val, uint8_t reg);
00265 
00266     /** @var m_spi
00267      *  @brief SPI object
00268      */
00269     SPI &m_spi;
00270 
00271     /** @var m_chip_enable
00272      *  @brief Chip Enable pin
00273      */
00274     /* chip enable pin */
00275 
00276     DigitalOut &m_chip_enable;
00277 };
00278 
00279 #endif