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@6:61f3693edd6c, 2019-02-13 (annotated)
- Committer:
- phonemacro
- Date:
- Wed Feb 13 22:17:06 2019 +0000
- Revision:
- 6:61f3693edd6c
- Parent:
- 4:a27a0ee318bd
correct initialization in write_trip_low, high.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
phonemacro | 3:3528e660168c | 1 | /******************************************************************************* |
phonemacro | 3:3528e660168c | 2 | * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved. |
phonemacro | 3:3528e660168c | 3 | * |
phonemacro | 3:3528e660168c | 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
phonemacro | 3:3528e660168c | 5 | * copy of this software and associated documentation files (the "Software"), |
phonemacro | 3:3528e660168c | 6 | * to deal in the Software without restriction, including without limitation |
phonemacro | 3:3528e660168c | 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
phonemacro | 3:3528e660168c | 8 | * and/or sell copies of the Software, and to permit persons to whom the |
phonemacro | 3:3528e660168c | 9 | * Software is furnished to do so, subject to the following conditions: |
phonemacro | 3:3528e660168c | 10 | * |
phonemacro | 3:3528e660168c | 11 | * The above copyright notice and this permission notice shall be included |
phonemacro | 3:3528e660168c | 12 | * in all copies or substantial portions of the Software. |
phonemacro | 3:3528e660168c | 13 | * |
phonemacro | 3:3528e660168c | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
phonemacro | 3:3528e660168c | 15 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
phonemacro | 3:3528e660168c | 16 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
phonemacro | 3:3528e660168c | 17 | * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES |
phonemacro | 3:3528e660168c | 18 | * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
phonemacro | 3:3528e660168c | 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
phonemacro | 3:3528e660168c | 20 | * OTHER DEALINGS IN THE SOFTWARE. |
phonemacro | 3:3528e660168c | 21 | * |
phonemacro | 3:3528e660168c | 22 | * Except as contained in this notice, the name of Maxim Integrated |
phonemacro | 3:3528e660168c | 23 | * Products, Inc. shall not be used except as stated in the Maxim Integrated |
phonemacro | 3:3528e660168c | 24 | * Products, Inc. Branding Policy. |
phonemacro | 3:3528e660168c | 25 | * |
phonemacro | 3:3528e660168c | 26 | * The mere transfer of this software does not imply any licenses |
phonemacro | 3:3528e660168c | 27 | * of trade secrets, proprietary technology, copyrights, patents, |
phonemacro | 3:3528e660168c | 28 | * trademarks, maskwork rights, or any other form of intellectual |
phonemacro | 3:3528e660168c | 29 | * property whatsoever. Maxim Integrated Products, Inc. retains all |
phonemacro | 3:3528e660168c | 30 | * ownership rights. |
phonemacro | 3:3528e660168c | 31 | ******************************************************************************* |
phonemacro | 3:3528e660168c | 32 | */ |
phonemacro | 3:3528e660168c | 33 | #include "max31875.h" |
phonemacro | 3:3528e660168c | 34 | #include "max31875_c.h" |
phonemacro | 3:3528e660168c | 35 | #include "mbed.h" |
phonemacro | 3:3528e660168c | 36 | // #include "USBSerial.h" |
phonemacro | 3:3528e660168c | 37 | |
phonemacro | 3:3528e660168c | 38 | |
phonemacro | 3:3528e660168c | 39 | /******************************************************************************/ |
phonemacro | 3:3528e660168c | 40 | /* C version for MAX31875 driver */ |
phonemacro | 3:3528e660168c | 41 | /******************************************************************************/ |
phonemacro | 3:3528e660168c | 42 | |
phonemacro | 3:3528e660168c | 43 | /* @var max31875_write_address, max31875_read_address |
phonemacro | 3:3528e660168c | 44 | * @brief I2C address |
phonemacro | 3:3528e660168c | 45 | */ |
phonemacro | 3:3528e660168c | 46 | uint8_t max31875_write_address, max31875_read_address; |
phonemacro | 3:3528e660168c | 47 | /* @var max31875_write_address, max31875_read_address |
phonemacro | 3:3528e660168c | 48 | * @brief max31875_extended_format |
phonemacro | 3:3528e660168c | 49 | */ |
phonemacro | 3:3528e660168c | 50 | uint32_t max31875_extended_format; |
phonemacro | 3:3528e660168c | 51 | |
phonemacro | 3:3528e660168c | 52 | int max31875_init(uint8_t slave_address) |
phonemacro | 3:3528e660168c | 53 | { |
phonemacro | 3:3528e660168c | 54 | max31875_write_address = (slave_address <<1); |
phonemacro | 3:3528e660168c | 55 | max31875_read_address = ((slave_address << 1) | 1); |
phonemacro | 3:3528e660168c | 56 | max31875_extended_format = 0; |
phonemacro | 3:3528e660168c | 57 | return MAX31875_NO_ERROR; |
phonemacro | 3:3528e660168c | 58 | } |
phonemacro | 3:3528e660168c | 59 | |
phonemacro | 3:3528e660168c | 60 | |
phonemacro | 3:3528e660168c | 61 | /******************************************************************************/ |
phonemacro | 3:3528e660168c | 62 | int max31875_read_reg(uint16_t *value, char reg, I2C &i2c_bus) |
phonemacro | 3:3528e660168c | 63 | { |
phonemacro | 3:3528e660168c | 64 | int32_t ret; |
phonemacro | 3:3528e660168c | 65 | char data[2] = {0, 0}; |
phonemacro | 3:3528e660168c | 66 | max31875_raw_data tmp; |
phonemacro | 3:3528e660168c | 67 | |
phonemacro | 3:3528e660168c | 68 | if (reg <= MAX31875_REG_MAX) { |
phonemacro | 3:3528e660168c | 69 | /* write to the Register Select */ |
phonemacro | 3:3528e660168c | 70 | ret = i2c_bus.write(max31875_write_address, ®, 1, true); |
phonemacro | 3:3528e660168c | 71 | /* read the two bytes of data */ |
phonemacro | 3:3528e660168c | 72 | if (ret == 0) { |
phonemacro | 3:3528e660168c | 73 | ret = i2c_bus.read(max31875_read_address, data, 2, false); |
phonemacro | 3:3528e660168c | 74 | if (ret == 0) { |
phonemacro | 4:a27a0ee318bd | 75 | tmp.msb = data[0]; |
phonemacro | 4:a27a0ee318bd | 76 | tmp.lsb = data[1]; |
phonemacro | 4:a27a0ee318bd | 77 | *value = tmp.uwrd; |
phonemacro | 3:3528e660168c | 78 | return MAX31875_NO_ERROR; |
phonemacro | 3:3528e660168c | 79 | } else { |
phonemacro | 3:3528e660168c | 80 | printf( |
phonemacro | 3:3528e660168c | 81 | "%s: failed to read data: ret: %d\r\n", __func__, ret); |
phonemacro | 3:3528e660168c | 82 | } |
phonemacro | 3:3528e660168c | 83 | } else { |
phonemacro | 3:3528e660168c | 84 | printf("%s: failed to write to Register Select: ret: %d\r\n", |
phonemacro | 3:3528e660168c | 85 | __func__, ret); |
phonemacro | 3:3528e660168c | 86 | } |
phonemacro | 3:3528e660168c | 87 | } else { |
phonemacro | 3:3528e660168c | 88 | printf("%s: register address is not correct: register: %d\r\n", |
phonemacro | 3:3528e660168c | 89 | __func__, reg); |
phonemacro | 3:3528e660168c | 90 | } |
phonemacro | 3:3528e660168c | 91 | return MAX31875_ERROR; |
phonemacro | 3:3528e660168c | 92 | } |
phonemacro | 3:3528e660168c | 93 | |
phonemacro | 3:3528e660168c | 94 | float max31875_read_reg_as_temperature(uint8_t reg, I2C &i2c_bus) |
phonemacro | 3:3528e660168c | 95 | { |
phonemacro | 3:3528e660168c | 96 | max31875_raw_data tmp; |
phonemacro | 3:3528e660168c | 97 | float temperature; |
phonemacro | 3:3528e660168c | 98 | if (reg == MAX31875_REG_TEMPERATURE || |
phonemacro | 4:a27a0ee318bd | 99 | reg == MAX31875_REG_THYST_LOW_TRIP || reg == MAX31875_REG_TOS_HIGH_TRIP) { |
phonemacro | 3:3528e660168c | 100 | max31875_read_reg(&tmp.uwrd, reg, i2c_bus); |
phonemacro | 4:a27a0ee318bd | 101 | temperature = (float)tmp.magnitude_bits; |
phonemacro | 3:3528e660168c | 102 | if (max31875_extended_format) |
phonemacro | 3:3528e660168c | 103 | temperature *= MAX31875_CF_EXTENDED_FORMAT; |
phonemacro | 3:3528e660168c | 104 | else |
phonemacro | 3:3528e660168c | 105 | temperature *= MAX31875_CF_NORMAL_FORMAT; |
phonemacro | 4:a27a0ee318bd | 106 | if (tmp.sign_bit) |
phonemacro | 4:a27a0ee318bd | 107 | temperature = -temperature; |
phonemacro | 4:a27a0ee318bd | 108 | return temperature; |
phonemacro | 4:a27a0ee318bd | 109 | |
phonemacro | 3:3528e660168c | 110 | return temperature; |
phonemacro | 3:3528e660168c | 111 | } else { |
phonemacro | 3:3528e660168c | 112 | printf("%s: register is invalid, %d r\n", __func__, reg); |
phonemacro | 3:3528e660168c | 113 | return 0; |
phonemacro | 3:3528e660168c | 114 | } |
phonemacro | 3:3528e660168c | 115 | } |
phonemacro | 3:3528e660168c | 116 | |
phonemacro | 3:3528e660168c | 117 | |
phonemacro | 3:3528e660168c | 118 | /******************************************************************************/ |
phonemacro | 3:3528e660168c | 119 | int max31875_write_reg(uint16_t value, char reg, I2C &i2c_bus) |
phonemacro | 3:3528e660168c | 120 | { |
phonemacro | 3:3528e660168c | 121 | int32_t ret; |
phonemacro | 3:3528e660168c | 122 | char cmd[3]; |
phonemacro | 3:3528e660168c | 123 | max31875_raw_data tmp; |
phonemacro | 3:3528e660168c | 124 | |
phonemacro | 3:3528e660168c | 125 | if (reg >= MAX31875_REG_CONFIGURATION && reg <= MAX31875_REG_MAX) { |
phonemacro | 3:3528e660168c | 126 | cmd[0] = reg; |
phonemacro | 3:3528e660168c | 127 | tmp.uwrd = value; |
phonemacro | 3:3528e660168c | 128 | cmd[1] = tmp.msb; |
phonemacro | 3:3528e660168c | 129 | cmd[2] = tmp.lsb; |
phonemacro | 3:3528e660168c | 130 | ret = i2c_bus.write(max31875_write_address, cmd, 3, false); |
phonemacro | 3:3528e660168c | 131 | if (ret == 0) { |
phonemacro | 4:a27a0ee318bd | 132 | if (MAX31875_REG_CONFIGURATION == reg) { |
phonemacro | 3:3528e660168c | 133 | max31875_extended_format = 0; |
phonemacro | 4:a27a0ee318bd | 134 | if (tmp.uwrd & MAX31875_CFG_EXTENDED_FORMAT) |
phonemacro | 4:a27a0ee318bd | 135 | max31875_extended_format = 1; |
phonemacro | 4:a27a0ee318bd | 136 | } |
phonemacro | 3:3528e660168c | 137 | return MAX31875_NO_ERROR; |
phonemacro | 3:3528e660168c | 138 | } else { |
phonemacro | 3:3528e660168c | 139 | printf("%s: I2C write error %d\r\n",__func__, ret); |
phonemacro | 3:3528e660168c | 140 | return MAX31875_ERROR; |
phonemacro | 3:3528e660168c | 141 | } |
phonemacro | 3:3528e660168c | 142 | } else { |
phonemacro | 3:3528e660168c | 143 | printf("%s: register value invalid %x\r\n",__func__, reg); |
phonemacro | 3:3528e660168c | 144 | return MAX31875_ERROR; |
phonemacro | 3:3528e660168c | 145 | } |
phonemacro | 3:3528e660168c | 146 | } |
phonemacro | 3:3528e660168c | 147 | |
phonemacro | 3:3528e660168c | 148 | |
phonemacro | 3:3528e660168c | 149 | int max31875_write_cfg(uint16_t cfg, I2C &i2c_bus) |
phonemacro | 3:3528e660168c | 150 | { |
phonemacro | 3:3528e660168c | 151 | return max31875_write_reg(cfg, MAX31875_REG_CONFIGURATION, i2c_bus); |
phonemacro | 3:3528e660168c | 152 | } |
phonemacro | 3:3528e660168c | 153 | |
phonemacro | 3:3528e660168c | 154 | |
phonemacro | 3:3528e660168c | 155 | int max31875_write_trip_low(float temperature, I2C &i2c_bus) |
phonemacro | 3:3528e660168c | 156 | { |
phonemacro | 3:3528e660168c | 157 | max31875_raw_data raw; |
phonemacro | 6:61f3693edd6c | 158 | raw.uwrd = 0; |
phonemacro | 4:a27a0ee318bd | 159 | if (temperature < 0) { |
phonemacro | 4:a27a0ee318bd | 160 | raw.sign_bit = 1; |
phonemacro | 4:a27a0ee318bd | 161 | temperature = -temperature; |
phonemacro | 4:a27a0ee318bd | 162 | } |
phonemacro | 3:3528e660168c | 163 | if (max31875_extended_format) |
phonemacro | 3:3528e660168c | 164 | temperature /= MAX31875_CF_EXTENDED_FORMAT; |
phonemacro | 3:3528e660168c | 165 | else |
phonemacro | 3:3528e660168c | 166 | temperature /= MAX31875_CF_NORMAL_FORMAT; |
phonemacro | 6:61f3693edd6c | 167 | raw.magnitude_bits = uint16_t(temperature); |
phonemacro | 4:a27a0ee318bd | 168 | return max31875_write_reg(raw.uwrd, MAX31875_REG_THYST_LOW_TRIP, i2c_bus); |
phonemacro | 3:3528e660168c | 169 | } |
phonemacro | 3:3528e660168c | 170 | |
phonemacro | 3:3528e660168c | 171 | |
phonemacro | 3:3528e660168c | 172 | int max31875_write_trip_high(float temperature, I2C &i2c_bus) |
phonemacro | 3:3528e660168c | 173 | { |
phonemacro | 3:3528e660168c | 174 | max31875_raw_data raw; |
phonemacro | 6:61f3693edd6c | 175 | raw.uwrd = 0; |
phonemacro | 4:a27a0ee318bd | 176 | if (temperature < 0) { |
phonemacro | 4:a27a0ee318bd | 177 | raw.sign_bit = 1; |
phonemacro | 4:a27a0ee318bd | 178 | temperature = -temperature; |
phonemacro | 4:a27a0ee318bd | 179 | } |
phonemacro | 3:3528e660168c | 180 | if (max31875_extended_format) |
phonemacro | 3:3528e660168c | 181 | temperature /= MAX31875_CF_EXTENDED_FORMAT; |
phonemacro | 3:3528e660168c | 182 | else |
phonemacro | 3:3528e660168c | 183 | temperature /= MAX31875_CF_NORMAL_FORMAT; |
phonemacro | 6:61f3693edd6c | 184 | raw.magnitude_bits = uint16_t(temperature); |
phonemacro | 4:a27a0ee318bd | 185 | return max31875_write_reg(raw.uwrd, MAX31875_REG_TOS_HIGH_TRIP, i2c_bus); |
phonemacro | 3:3528e660168c | 186 | } |
phonemacro | 3:3528e660168c | 187 | |
phonemacro | 3:3528e660168c | 188 | |
phonemacro | 3:3528e660168c | 189 | float max31875_celsius_to_fahrenheit(float temp_c) |
phonemacro | 3:3528e660168c | 190 | { |
phonemacro | 3:3528e660168c | 191 | float temp_f; |
phonemacro | 3:3528e660168c | 192 | temp_f = ((temp_c * 9)/5) + 32; |
phonemacro | 3:3528e660168c | 193 | return temp_f; |
phonemacro | 3:3528e660168c | 194 | } |