Diff: max31875.h

Revision:

0:f51465145906

Child:

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+/*******************************************************************************
+* Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* 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 AND NONINFRINGEMENT.
+* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+*******************************************************************************
+* @file MAX31875.h
+*******************************************************************************
+*/
+#ifndef MAX31875_H
+#define MAX31875_H
+#include "mbed.h"
+
+#define MAX31875_NO_ERROR   0
+#define MAX31875_ERROR      -1
+
+#define MAX31875_REG_TEMPERATURE   0X00
+#define MAX31875_REG_CONFIGURATION 0X01
+#define MAX31875_REG_THYST         0X02
+#define MAX31875_REG_TOS           0X03
+#define MAX31875_REG_MAX           0X03
+
+#define MAX31875_CFG_ONE_SHOT_START   (1) /* Start one-shot measurement */
+
+#define MAX31875_CFG_CONV_RATE_0_25   (0x00 << 1) /* 0.25 conversions/sec */
+#define MAX31875_CFG_CONV_RATE_1      (0x01 << 1) /* 1.0 conversions/sec */
+#define MAX31875_CFG_CONV_RATE_4      (0x02 << 1) /* 4.0 conversions/sec */
+#define MAX31875_CFG_CONV_RATE_8      (0x03 << 1) /* 8.0 conversions/sec */
+#define MAX31875_WAIT_CONV_RATE_0_25 (4.0)
+#define MAX31875_WAIT_CONV_RATE_1    (1.0)
+#define MAX31875_WAIT_CONV_RATE_4    (0.25)
+#define MAX31875_WAIT_CONV_RATE_8    (0.125)
+
+#define MAX31875_CFG_RESOLUTION_9BIT  (0x00 << 5)
+#define MAX31875_CFG_RESOLUTION_10BIT (0x01 << 5)
+#define MAX31875_CFG_RESOLUTION_11BIT (0x02 << 5)
+#define MAX31875_CFG_RESOLUTION_12BIT (0x03 << 5)
+
+#define MAX31875_CFG_NORMAL_FORMAT    (0X00 << 7)
+#define MAX31875_CFG_EXTENDED_FORMAT  (0X01 << 7)
+
+#define MAX31875_CFG_CONTINUOUS       (0X00 << 8)
+#define MAX31875_CFG_SHUTDOWN         (0X01 << 8)
+
+#define MAX31875_CFG_COMPARATOR_MODE  (0X00 << 9)
+#define MAX31875_CFG_INTERRUPT_MODE   (0X01 << 9)
+
+
+#define MAX31875_CFG_FAULT_FILTER_1   (0x00 << 11)
+#define MAX31875_CFG_FAULT_FILTER_2   (0x01 << 11)
+#define MAX31875_CFG_FAULT_FILTER_4   (0x02 << 11)
+#define MAX31875_CFG_FAULT_FILTER_6   (0x03 << 11)
+
+#define MAX31875_CFG_OVER_TEMP_MASK   (0x80)
+
+
+#define MAX31875_I2C_SLAVE_ADR_R0 (0x90 >> 1) // code uses the 7 bit address
+#define MAX31875_I2C_SLAVE_ADR_R1 (0x92 >> 1)
+#define MAX31875_I2C_SLAVE_ADR_R2 (0x94 >> 1)
+#define MAX31875_I2C_SLAVE_ADR_R3 (0x96 >> 1)
+#define MAX31875_I2C_SLAVE_ADR_R4 (0x98 >> 1)
+#define MAX31875_I2C_SLAVE_ADR_R5 (0x9A >> 1)
+#define MAX31875_I2C_SLAVE_ADR_R6 (0x9C >> 1)
+#define MAX31875_I2C_SLAVE_ADR_R7 (0x9E >> 1)
+
+#define MAX31875_CF_NORMAL_FORMAT (0.00390625F)
+#define MAX31875_CF_EXTENDED_FORMAT (0.0078125F)
+
+/**
+ * @brief Extremely small low-power temperature sensor.
+ * @version 1.0000.0000
+ *
+ * @details The MAX31875 is a small WLP package temperature sensor.
+ * It supports high, low triggers stored in EEPROM for hystersis
+ * or limit alarms using comparator or interrupt mode.
+ * The MAX31875 can operate in shutdown and one-shot mode for
+ * extremely low power applications.
+ * Tiny size of 0.84 x 0.84 x 0.35 mm.
+ * Accuracy is +-1.5°C from +10°C to +45°C  (±0.5°C Typical),
+ *             +-2.0°C from -10°C to +100°C (±0.6°C Typical),
+ *             +-3.0°C from -20°C to +125°C (±1.0°C Typical),
+ * I2C data rate of up to 1 MHz.
+ *
+ * @code 
+ * #include "mbed.h"
+ * #include "max32630fthr.h"
+ * #include "max31875.h"
+ * #include "USBSerial.h"
+ * MAX32630FTHR pegasus(MAX32630FTHR::VIO_1V8); 
+ * I2C i2cBus(P3_4, P3_5);
+ * int main()
+ * {
+ *     uint16_t raw;
+ *     float temperature;
+ *     DigitalOut rLED(LED1, LED_OFF);
+ *     DigitalOut gLED(LED2, LED_OFF);
+ *     DigitalOut bLED(LED3, LED_OFF);
+ *     gLED = LED_ON;
+ *     MAX31875 temp_sensor(i2cBus, MAX31875_I2C_SLAVE_ADR_R0);
+ *    i2cBus.frequency(1000000);
+ *    temp_sensor.write_reg(uint16_t(MAX31875_CFG_CONV_RATE_8 | 
+ *        MAX31875_CFG_RESOLUTION_12BIT), MAX31875_REG_CONFIGURATION);
+ *    wait(MAX31875_WAIT_CONV_RATE_8);
+ *     temperature = temp_sensor.read_reg_as_temperature(MAX31875_REG_TEMPERATURE);
+ *     printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+ *             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
+ * }
+ * @endcode
+ */
+
+class MAX31875
+{
+    public:
+
+    /**********************************************************//**
+     * @brief Constructor for MAX31875 Class.  
+     * 
+     * @details Allows user to use existing I2C object
+     *
+     * On Entry:
+     *     @param[in] i2c_bus - pointer to existing I2C object
+     *     @param[in] i2c_adrs - 7-bit slave address of MAX31875
+     *
+     * On Exit:
+     *
+     * @return None
+     **************************************************************/
+    MAX31875(I2C &i2c_bus, uint8_t slaveAddress);
+ 
+    /**********************************************************//**
+     * @brief Default destructor for MAX31875 Class.  
+     *
+     * @details Destroys I2C object if owner 
+     *
+     * On Entry:
+     *
+     * On Exit:
+     *
+     * @return None
+     **************************************************************/
+    ~MAX31875();
+
+    /**
+     * @brief  Read register of device at slave address
+     * @param[out] value - Read data on success
+     * @param reg - Register address
+     * @return 0 on success, negative number on failure
+     */
+    int read_reg(uint16_t *value, char reg);
+
+    /** 
+     * @brief Reads the temperature registers
+     * @param reg - the address of the temperature register
+     * @return temprature in degrees Celsius
+     */
+    float read_reg_as_temperature(uint8_t reg);
+
+    /** 
+     * @brief Writes the configuration register
+     * @return 0 on success, negative number on failure
+     */
+     int write_cfg(uint16_t cfg);
+
+    /** 
+     * @brief Writes the THYST register
+     * @return 0 on success, negative number on failure
+     */
+     int write_trip_low(float temperature);
+
+    /** 
+     * @brief Writes the TOS register
+     * @return 0 on success, negative number on failure
+     */
+     int write_trip_high(float temperature);
+
+    /** 
+     * @brief Converts Celcius degrees to Fahrenheit
+     * @param temp_c - the temperature in Celsius degrees
+     * @return 0 on success, negative number on failure
+     */
+     float celsius_to_fahrenheit(float temp_c);
+
+protected: 
+    /** union data structure for byte word manipulations */
+    union max31875_raw_data {
+        struct {
+            uint8_t lsb;
+            uint8_t msb;
+        };
+        uint16_t uwrd;
+        int16_t swrd;
+    };
+
+    /** 
+     * @brief Write a value to a register
+     * @param value - value to write to the register
+     * @param reg - register address
+     * @return 0 on success, negative number on failure
+     */
+    int write_reg(uint16_t value, char reg);
+
+private:
+    /** I2C object */
+    I2C &m_i2c;
+    /** Device slave addresses */
+    uint8_t m_writeAddress, m_readAddress;
+    /** Extended Data Format flag. */
+    uint32_t m_extended_format;
+};
+ 
+#endif/* MAX31875_H */
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