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@0:f51465145906, 2019-02-03 (annotated)
- Committer:
- phonemacro
- Date:
- Sun Feb 03 23:50:17 2019 +0000
- Revision:
- 0:f51465145906
Initial Commit
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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phonemacro | 0:f51465145906 | 1 | /******************************************************************************* |
phonemacro | 0:f51465145906 | 2 | * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved. |
phonemacro | 0:f51465145906 | 3 | * |
phonemacro | 0:f51465145906 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
phonemacro | 0:f51465145906 | 5 | * copy of this software and associated documentation files (the "Software"), |
phonemacro | 0:f51465145906 | 6 | * to deal in the Software without restriction, including without limitation |
phonemacro | 0:f51465145906 | 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
phonemacro | 0:f51465145906 | 8 | * and/or sell copies of the Software, and to permit persons to whom the |
phonemacro | 0:f51465145906 | 9 | * Software is furnished to do so, subject to the following conditions: |
phonemacro | 0:f51465145906 | 10 | * |
phonemacro | 0:f51465145906 | 11 | * The above copyright notice and this permission notice shall be included |
phonemacro | 0:f51465145906 | 12 | * in all copies or substantial portions of the Software. |
phonemacro | 0:f51465145906 | 13 | * |
phonemacro | 0:f51465145906 | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
phonemacro | 0:f51465145906 | 15 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
phonemacro | 0:f51465145906 | 16 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
phonemacro | 0:f51465145906 | 17 | * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES |
phonemacro | 0:f51465145906 | 18 | * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
phonemacro | 0:f51465145906 | 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
phonemacro | 0:f51465145906 | 20 | * OTHER DEALINGS IN THE SOFTWARE. |
phonemacro | 0:f51465145906 | 21 | * |
phonemacro | 0:f51465145906 | 22 | * Except as contained in this notice, the name of Maxim Integrated |
phonemacro | 0:f51465145906 | 23 | * Products, Inc. shall not be used except as stated in the Maxim Integrated |
phonemacro | 0:f51465145906 | 24 | * Products, Inc. Branding Policy. |
phonemacro | 0:f51465145906 | 25 | * |
phonemacro | 0:f51465145906 | 26 | * The mere transfer of this software does not imply any licenses |
phonemacro | 0:f51465145906 | 27 | * of trade secrets, proprietary technology, copyrights, patents, |
phonemacro | 0:f51465145906 | 28 | * trademarks, maskwork rights, or any other form of intellectual |
phonemacro | 0:f51465145906 | 29 | * property whatsoever. Maxim Integrated Products, Inc. retains all |
phonemacro | 0:f51465145906 | 30 | * ownership rights. |
phonemacro | 0:f51465145906 | 31 | ******************************************************************************* |
phonemacro | 0:f51465145906 | 32 | */ |
phonemacro | 0:f51465145906 | 33 | #include "max31875.h" |
phonemacro | 0:f51465145906 | 34 | #include "mbed.h" |
phonemacro | 0:f51465145906 | 35 | // #include "USBSerial.h" |
phonemacro | 0:f51465145906 | 36 | |
phonemacro | 0:f51465145906 | 37 | |
phonemacro | 0:f51465145906 | 38 | /******************************************************************************/ |
phonemacro | 0:f51465145906 | 39 | MAX31875::MAX31875(I2C &i2c_bus, uint8_t slaveAddress): |
phonemacro | 0:f51465145906 | 40 | m_i2c(i2c_bus), |
phonemacro | 0:f51465145906 | 41 | m_writeAddress(slaveAddress <<1), |
phonemacro | 0:f51465145906 | 42 | m_readAddress ((slaveAddress << 1) | 1), |
phonemacro | 0:f51465145906 | 43 | m_extended_format(0) |
phonemacro | 0:f51465145906 | 44 | { |
phonemacro | 0:f51465145906 | 45 | } |
phonemacro | 0:f51465145906 | 46 | |
phonemacro | 0:f51465145906 | 47 | |
phonemacro | 0:f51465145906 | 48 | /******************************************************************************/ |
phonemacro | 0:f51465145906 | 49 | MAX31875::~MAX31875(void) |
phonemacro | 0:f51465145906 | 50 | { |
phonemacro | 0:f51465145906 | 51 | /** empty block */ |
phonemacro | 0:f51465145906 | 52 | } |
phonemacro | 0:f51465145906 | 53 | |
phonemacro | 0:f51465145906 | 54 | |
phonemacro | 0:f51465145906 | 55 | /******************************************************************************/ |
phonemacro | 0:f51465145906 | 56 | int MAX31875::read_reg(uint16_t *value, char reg) |
phonemacro | 0:f51465145906 | 57 | { |
phonemacro | 0:f51465145906 | 58 | int32_t ret; |
phonemacro | 0:f51465145906 | 59 | char data[2] = {0, 0}; |
phonemacro | 0:f51465145906 | 60 | max31875_raw_data tmp; |
phonemacro | 0:f51465145906 | 61 | |
phonemacro | 0:f51465145906 | 62 | if (reg <= MAX31875_REG_MAX) { |
phonemacro | 0:f51465145906 | 63 | /* write to the Register Select */ |
phonemacro | 0:f51465145906 | 64 | ret = m_i2c.write(m_writeAddress, ®, 1, true); |
phonemacro | 0:f51465145906 | 65 | /* read the two bytes of data */ |
phonemacro | 0:f51465145906 | 66 | if (ret == 0) { |
phonemacro | 0:f51465145906 | 67 | ret = m_i2c.read(m_readAddress, data, 2, false); |
phonemacro | 0:f51465145906 | 68 | if (ret == 0) { |
phonemacro | 0:f51465145906 | 69 | tmp.msb = data[0]; /* MSB */ |
phonemacro | 0:f51465145906 | 70 | tmp.lsb = data[1]; /* LSB */ |
phonemacro | 0:f51465145906 | 71 | *value = tmp.swrd; |
phonemacro | 0:f51465145906 | 72 | return MAX31875_NO_ERROR; |
phonemacro | 0:f51465145906 | 73 | } else { |
phonemacro | 0:f51465145906 | 74 | printf( |
phonemacro | 0:f51465145906 | 75 | "%s: failed to read data: ret: %d\r\n", __func__, ret); |
phonemacro | 0:f51465145906 | 76 | } |
phonemacro | 0:f51465145906 | 77 | } else { |
phonemacro | 0:f51465145906 | 78 | printf("%s: failed to write to Register Select: ret: %d\r\n", |
phonemacro | 0:f51465145906 | 79 | __func__, ret); |
phonemacro | 0:f51465145906 | 80 | } |
phonemacro | 0:f51465145906 | 81 | } else { |
phonemacro | 0:f51465145906 | 82 | printf("%s: register address is not correct: register: %d\r\n", |
phonemacro | 0:f51465145906 | 83 | __func__, reg); |
phonemacro | 0:f51465145906 | 84 | } |
phonemacro | 0:f51465145906 | 85 | return MAX31875_ERROR; |
phonemacro | 0:f51465145906 | 86 | } |
phonemacro | 0:f51465145906 | 87 | |
phonemacro | 0:f51465145906 | 88 | |
phonemacro | 0:f51465145906 | 89 | float MAX31875::read_reg_as_temperature(uint8_t reg) |
phonemacro | 0:f51465145906 | 90 | { |
phonemacro | 0:f51465145906 | 91 | max31875_raw_data tmp; |
phonemacro | 0:f51465145906 | 92 | float temperature; |
phonemacro | 0:f51465145906 | 93 | if (reg == MAX31875_REG_TEMPERATURE || |
phonemacro | 0:f51465145906 | 94 | reg == MAX31875_REG_THYST || reg == MAX31875_REG_TOS) { |
phonemacro | 0:f51465145906 | 95 | read_reg(&tmp.uwrd, reg); |
phonemacro | 0:f51465145906 | 96 | temperature = (float)tmp.swrd; |
phonemacro | 0:f51465145906 | 97 | if (m_extended_format) |
phonemacro | 0:f51465145906 | 98 | temperature *= MAX31875_CF_EXTENDED_FORMAT; |
phonemacro | 0:f51465145906 | 99 | else |
phonemacro | 0:f51465145906 | 100 | temperature *= MAX31875_CF_NORMAL_FORMAT; |
phonemacro | 0:f51465145906 | 101 | return temperature; |
phonemacro | 0:f51465145906 | 102 | } else { |
phonemacro | 0:f51465145906 | 103 | printf("%s: register is invalid, %d r\n", __func__, reg); |
phonemacro | 0:f51465145906 | 104 | return 0; |
phonemacro | 0:f51465145906 | 105 | } |
phonemacro | 0:f51465145906 | 106 | } |
phonemacro | 0:f51465145906 | 107 | |
phonemacro | 0:f51465145906 | 108 | |
phonemacro | 0:f51465145906 | 109 | /******************************************************************************/ |
phonemacro | 0:f51465145906 | 110 | int MAX31875::write_reg(uint16_t value, char reg) |
phonemacro | 0:f51465145906 | 111 | { |
phonemacro | 0:f51465145906 | 112 | int32_t ret; |
phonemacro | 0:f51465145906 | 113 | char cmd[3]; |
phonemacro | 0:f51465145906 | 114 | max31875_raw_data tmp; |
phonemacro | 0:f51465145906 | 115 | |
phonemacro | 0:f51465145906 | 116 | if (reg >= MAX31875_REG_CONFIGURATION && reg <= MAX31875_REG_MAX) { |
phonemacro | 0:f51465145906 | 117 | cmd[0] = reg; |
phonemacro | 0:f51465145906 | 118 | tmp.uwrd = value; |
phonemacro | 0:f51465145906 | 119 | cmd[1] = tmp.msb; |
phonemacro | 0:f51465145906 | 120 | cmd[2] = tmp.lsb; |
phonemacro | 0:f51465145906 | 121 | ret = m_i2c.write(m_writeAddress, cmd, 3, false); |
phonemacro | 0:f51465145906 | 122 | if (ret == 0) { |
phonemacro | 0:f51465145906 | 123 | if (tmp.uwrd & MAX31875_CFG_EXTENDED_FORMAT) |
phonemacro | 0:f51465145906 | 124 | m_extended_format = 1; |
phonemacro | 0:f51465145906 | 125 | else |
phonemacro | 0:f51465145906 | 126 | m_extended_format = 0; |
phonemacro | 0:f51465145906 | 127 | return MAX31875_NO_ERROR; |
phonemacro | 0:f51465145906 | 128 | } else { |
phonemacro | 0:f51465145906 | 129 | printf("%s: I2C write error %d\r\n",__func__, ret); |
phonemacro | 0:f51465145906 | 130 | return MAX31875_ERROR; |
phonemacro | 0:f51465145906 | 131 | } |
phonemacro | 0:f51465145906 | 132 | } else { |
phonemacro | 0:f51465145906 | 133 | printf("%s: register value invalid %x\r\n",__func__, reg); |
phonemacro | 0:f51465145906 | 134 | return MAX31875_ERROR; |
phonemacro | 0:f51465145906 | 135 | } |
phonemacro | 0:f51465145906 | 136 | } |
phonemacro | 0:f51465145906 | 137 | |
phonemacro | 0:f51465145906 | 138 | |
phonemacro | 0:f51465145906 | 139 | int MAX31875::write_cfg(uint16_t cfg) |
phonemacro | 0:f51465145906 | 140 | { |
phonemacro | 0:f51465145906 | 141 | return write_reg(cfg, MAX31875_REG_CONFIGURATION); |
phonemacro | 0:f51465145906 | 142 | } |
phonemacro | 0:f51465145906 | 143 | |
phonemacro | 0:f51465145906 | 144 | |
phonemacro | 0:f51465145906 | 145 | int MAX31875::write_trip_low(float temperature) |
phonemacro | 0:f51465145906 | 146 | { |
phonemacro | 0:f51465145906 | 147 | max31875_raw_data raw; |
phonemacro | 0:f51465145906 | 148 | if (m_extended_format) |
phonemacro | 0:f51465145906 | 149 | temperature /= MAX31875_CF_EXTENDED_FORMAT; |
phonemacro | 0:f51465145906 | 150 | else |
phonemacro | 0:f51465145906 | 151 | temperature /= MAX31875_CF_NORMAL_FORMAT; |
phonemacro | 0:f51465145906 | 152 | raw.uwrd = uint16_t(temperature); |
phonemacro | 0:f51465145906 | 153 | return write_reg(raw.uwrd, MAX31875_REG_THYST); |
phonemacro | 0:f51465145906 | 154 | } |
phonemacro | 0:f51465145906 | 155 | |
phonemacro | 0:f51465145906 | 156 | |
phonemacro | 0:f51465145906 | 157 | int MAX31875::write_trip_high(float temperature) |
phonemacro | 0:f51465145906 | 158 | { |
phonemacro | 0:f51465145906 | 159 | max31875_raw_data raw; |
phonemacro | 0:f51465145906 | 160 | if (m_extended_format) |
phonemacro | 0:f51465145906 | 161 | temperature /= MAX31875_CF_EXTENDED_FORMAT; |
phonemacro | 0:f51465145906 | 162 | else |
phonemacro | 0:f51465145906 | 163 | temperature /= MAX31875_CF_NORMAL_FORMAT; |
phonemacro | 0:f51465145906 | 164 | raw.uwrd = uint16_t(temperature); |
phonemacro | 0:f51465145906 | 165 | return write_reg(raw.uwrd, MAX31875_REG_TOS); |
phonemacro | 0:f51465145906 | 166 | } |
phonemacro | 0:f51465145906 | 167 | |
phonemacro | 0:f51465145906 | 168 | |
phonemacro | 0:f51465145906 | 169 | float MAX31875::celsius_to_fahrenheit(float temp_c) |
phonemacro | 0:f51465145906 | 170 | { |
phonemacro | 0:f51465145906 | 171 | float temp_f; |
phonemacro | 0:f51465145906 | 172 | temp_f = ((temp_c * 9)/5) + 32; |
phonemacro | 0:f51465145906 | 173 | return temp_f; |
phonemacro | 0:f51465145906 | 174 | } |