C++ library, driver software code for the low-power small WLP package MAX31875 temperature sensor. Code supports one-shot, shut-down/standby, hysteresis, alarm limits.
Dependents: MAX31875_Temperature_Sensor_Small_Package
max31875.h
- Committer:
- phonemacro
- Date:
- 2019-02-04
- Revision:
- 1:98499c3dace6
- Parent:
- 0:f51465145906
- Child:
- 2:048eff228fd8
File content as of revision 1:98499c3dace6:
/******************************************************************************* * 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 to the configuration register * @param cfg - configurate word * @return 0 on success, negative number on failure */ int write_cfg(uint16_t cfg); /** * @brief Writes to the THYST register * @param temperature - the temperature in Celsius degrees * @return 0 on success, negative number on failure */ int write_trip_low(float temperature); /** * @brief Writes to the TOS register * @param temperature - the temperature in Celsius degrees * @return 0 on success, negative number on failure */ int write_trip_high(float temperature); /** * @brief Converts Celsius degrees to Fahrenheit * @param temp_c - the temperature in Celsius degrees * @return temperature in Celsius degrees */ 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 */