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.cpp
- Committer:
- phonemacro
- Date:
- 2019-02-03
- Revision:
- 0:f51465145906
File content as of revision 0:f51465145906:
/******************************************************************************* * 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 "mbed.h" // #include "USBSerial.h" /******************************************************************************/ MAX31875::MAX31875(I2C &i2c_bus, uint8_t slaveAddress): m_i2c(i2c_bus), m_writeAddress(slaveAddress <<1), m_readAddress ((slaveAddress << 1) | 1), m_extended_format(0) { } /******************************************************************************/ MAX31875::~MAX31875(void) { /** empty block */ } /******************************************************************************/ int MAX31875::read_reg(uint16_t *value, char reg) { int32_t ret; char data[2] = {0, 0}; max31875_raw_data tmp; if (reg <= MAX31875_REG_MAX) { /* write to the Register Select */ ret = m_i2c.write(m_writeAddress, ®, 1, true); /* read the two bytes of data */ if (ret == 0) { ret = m_i2c.read(m_readAddress, data, 2, false); if (ret == 0) { tmp.msb = data[0]; /* MSB */ tmp.lsb = data[1]; /* LSB */ *value = tmp.swrd; 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) { max31875_raw_data tmp; float temperature; if (reg == MAX31875_REG_TEMPERATURE || reg == MAX31875_REG_THYST || reg == MAX31875_REG_TOS) { read_reg(&tmp.uwrd, reg); temperature = (float)tmp.swrd; if (m_extended_format) temperature *= MAX31875_CF_EXTENDED_FORMAT; else temperature *= MAX31875_CF_NORMAL_FORMAT; return temperature; } else { printf("%s: register is invalid, %d r\n", __func__, reg); return 0; } } /******************************************************************************/ int MAX31875::write_reg(uint16_t value, char reg) { 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 = m_i2c.write(m_writeAddress, cmd, 3, false); if (ret == 0) { if (tmp.uwrd & MAX31875_CFG_EXTENDED_FORMAT) m_extended_format = 1; else m_extended_format = 0; 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) { return write_reg(cfg, MAX31875_REG_CONFIGURATION); } int MAX31875::write_trip_low(float temperature) { max31875_raw_data raw; if (m_extended_format) temperature /= MAX31875_CF_EXTENDED_FORMAT; else temperature /= MAX31875_CF_NORMAL_FORMAT; raw.uwrd = uint16_t(temperature); return write_reg(raw.uwrd, MAX31875_REG_THYST); } int MAX31875::write_trip_high(float temperature) { max31875_raw_data raw; if (m_extended_format) temperature /= MAX31875_CF_EXTENDED_FORMAT; else temperature /= MAX31875_CF_NORMAL_FORMAT; raw.uwrd = uint16_t(temperature); return write_reg(raw.uwrd, MAX31875_REG_TOS); } float MAX31875::celsius_to_fahrenheit(float temp_c) { float temp_f; temp_f = ((temp_c * 9)/5) + 32; return temp_f; }