C code and C++ library, driver software 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_WLP Click-Sensor-MAX31875 NuMaker-mbed-Sensor-MAX31875
max31875_c.cpp
- Committer:
- phonemacro
- Date:
- 2019-02-13
- Revision:
- 6:61f3693edd6c
- Parent:
- 4:a27a0ee318bd
File content as of revision 6:61f3693edd6c:
/******************************************************************************* * 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. ******************************************************************************* */ #include "max31875.h" #include "max31875_c.h" #include "mbed.h" // #include "USBSerial.h" /******************************************************************************/ /* C version for MAX31875 driver */ /******************************************************************************/ /* @var max31875_write_address, max31875_read_address * @brief I2C address */ uint8_t max31875_write_address, max31875_read_address; /* @var max31875_write_address, max31875_read_address * @brief max31875_extended_format */ uint32_t max31875_extended_format; int max31875_init(uint8_t slave_address) { max31875_write_address = (slave_address <<1); max31875_read_address = ((slave_address << 1) | 1); max31875_extended_format = 0; return MAX31875_NO_ERROR; } /******************************************************************************/ int max31875_read_reg(uint16_t *value, char reg, I2C &i2c_bus) { int32_t ret; char data[2] = {0, 0}; max31875_raw_data tmp; if (reg <= MAX31875_REG_MAX) { /* write to the Register Select */ ret = i2c_bus.write(max31875_write_address, ®, 1, true); /* read the two bytes of data */ if (ret == 0) { ret = i2c_bus.read(max31875_read_address, data, 2, false); if (ret == 0) { tmp.msb = data[0]; tmp.lsb = data[1]; *value = tmp.uwrd; return MAX31875_NO_ERROR; } else { printf( "%s: failed to read data: ret: %d\r\n", __func__, ret); } } else { printf("%s: failed to write to Register Select: ret: %d\r\n", __func__, ret); } } else { printf("%s: register address is not correct: register: %d\r\n", __func__, reg); } return MAX31875_ERROR; } float max31875_read_reg_as_temperature(uint8_t reg, I2C &i2c_bus) { max31875_raw_data tmp; float temperature; if (reg == MAX31875_REG_TEMPERATURE || reg == MAX31875_REG_THYST_LOW_TRIP || reg == MAX31875_REG_TOS_HIGH_TRIP) { max31875_read_reg(&tmp.uwrd, reg, i2c_bus); temperature = (float)tmp.magnitude_bits; if (max31875_extended_format) temperature *= MAX31875_CF_EXTENDED_FORMAT; else temperature *= MAX31875_CF_NORMAL_FORMAT; if (tmp.sign_bit) temperature = -temperature; return temperature; return temperature; } else { printf("%s: register is invalid, %d r\n", __func__, reg); return 0; } } /******************************************************************************/ int max31875_write_reg(uint16_t value, char reg, I2C &i2c_bus) { int32_t ret; char cmd[3]; max31875_raw_data tmp; if (reg >= MAX31875_REG_CONFIGURATION && reg <= MAX31875_REG_MAX) { cmd[0] = reg; tmp.uwrd = value; cmd[1] = tmp.msb; cmd[2] = tmp.lsb; ret = i2c_bus.write(max31875_write_address, cmd, 3, false); if (ret == 0) { if (MAX31875_REG_CONFIGURATION == reg) { max31875_extended_format = 0; if (tmp.uwrd & MAX31875_CFG_EXTENDED_FORMAT) max31875_extended_format = 1; } return MAX31875_NO_ERROR; } else { printf("%s: I2C write error %d\r\n",__func__, ret); return MAX31875_ERROR; } } else { printf("%s: register value invalid %x\r\n",__func__, reg); return MAX31875_ERROR; } } int max31875_write_cfg(uint16_t cfg, I2C &i2c_bus) { return max31875_write_reg(cfg, MAX31875_REG_CONFIGURATION, i2c_bus); } int max31875_write_trip_low(float temperature, I2C &i2c_bus) { max31875_raw_data raw; raw.uwrd = 0; if (temperature < 0) { raw.sign_bit = 1; temperature = -temperature; } if (max31875_extended_format) temperature /= MAX31875_CF_EXTENDED_FORMAT; else temperature /= MAX31875_CF_NORMAL_FORMAT; raw.magnitude_bits = uint16_t(temperature); return max31875_write_reg(raw.uwrd, MAX31875_REG_THYST_LOW_TRIP, i2c_bus); } int max31875_write_trip_high(float temperature, I2C &i2c_bus) { max31875_raw_data raw; raw.uwrd = 0; if (temperature < 0) { raw.sign_bit = 1; temperature = -temperature; } if (max31875_extended_format) temperature /= MAX31875_CF_EXTENDED_FORMAT; else temperature /= MAX31875_CF_NORMAL_FORMAT; raw.magnitude_bits = uint16_t(temperature); return max31875_write_reg(raw.uwrd, MAX31875_REG_TOS_HIGH_TRIP, i2c_bus); } float max31875_celsius_to_fahrenheit(float temp_c) { float temp_f; temp_f = ((temp_c * 9)/5) + 32; return temp_f; }