C++ driver software code for Maxim Integrated MAX31723/MAX31722 device temperature sensor. The MAX31723 provides 9 to 12 bits of resolution.
Dependents: MAX31723_Thermostat_Thermometer_Sensor
max31723.cpp@0:4a3d6ac5042d, 2019-01-26 (annotated)
- Committer:
- phonemacro
- Date:
- Sat Jan 26 23:55:38 2019 +0000
- Revision:
- 0:4a3d6ac5042d
- Child:
- 1:bb6f11be119f
Initial commit for one-shot temperature readings.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
phonemacro | 0:4a3d6ac5042d | 1 | /******************************************************************************* |
phonemacro | 0:4a3d6ac5042d | 2 | * Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved. |
phonemacro | 0:4a3d6ac5042d | 3 | * |
phonemacro | 0:4a3d6ac5042d | 4 | * Permission is hereby granted, free of charge, to any person obtaining a |
phonemacro | 0:4a3d6ac5042d | 5 | * copy of this software and associated documentation files (the "Software"), |
phonemacro | 0:4a3d6ac5042d | 6 | * to deal in the Software without restriction, including without limitation |
phonemacro | 0:4a3d6ac5042d | 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
phonemacro | 0:4a3d6ac5042d | 8 | * and/or sell copies of the Software, and to permit persons to whom the |
phonemacro | 0:4a3d6ac5042d | 9 | * Software is furnished to do so, subject to the following conditions: |
phonemacro | 0:4a3d6ac5042d | 10 | * |
phonemacro | 0:4a3d6ac5042d | 11 | * The above copyright notice and this permission notice shall be included |
phonemacro | 0:4a3d6ac5042d | 12 | * in all copies or substantial portions of the Software. |
phonemacro | 0:4a3d6ac5042d | 13 | * |
phonemacro | 0:4a3d6ac5042d | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
phonemacro | 0:4a3d6ac5042d | 15 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
phonemacro | 0:4a3d6ac5042d | 16 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
phonemacro | 0:4a3d6ac5042d | 17 | * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES |
phonemacro | 0:4a3d6ac5042d | 18 | * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
phonemacro | 0:4a3d6ac5042d | 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
phonemacro | 0:4a3d6ac5042d | 20 | * OTHER DEALINGS IN THE SOFTWARE. |
phonemacro | 0:4a3d6ac5042d | 21 | * |
phonemacro | 0:4a3d6ac5042d | 22 | * Except as contained in this notice, the name of Maxim Integrated |
phonemacro | 0:4a3d6ac5042d | 23 | * Products, Inc. shall not be used except as stated in the Maxim Integrated |
phonemacro | 0:4a3d6ac5042d | 24 | * Products, Inc. Branding Policy. |
phonemacro | 0:4a3d6ac5042d | 25 | * |
phonemacro | 0:4a3d6ac5042d | 26 | * The mere transfer of this software does not imply any licenses |
phonemacro | 0:4a3d6ac5042d | 27 | * of trade secrets, proprietary technology, copyrights, patents, |
phonemacro | 0:4a3d6ac5042d | 28 | * trademarks, maskwork rights, or any other form of intellectual |
phonemacro | 0:4a3d6ac5042d | 29 | * property whatsoever. Maxim Integrated Products, Inc. retains all |
phonemacro | 0:4a3d6ac5042d | 30 | * ownership rights. |
phonemacro | 0:4a3d6ac5042d | 31 | ******************************************************************************* |
phonemacro | 0:4a3d6ac5042d | 32 | */ |
phonemacro | 0:4a3d6ac5042d | 33 | #include "max31723.h" |
phonemacro | 0:4a3d6ac5042d | 34 | |
phonemacro | 0:4a3d6ac5042d | 35 | MAX31723::MAX31723(SPI &spi, DigitalOut &ce_pin) : m_spi(spi), m_chip_enable(ce_pin) |
phonemacro | 0:4a3d6ac5042d | 36 | { |
phonemacro | 0:4a3d6ac5042d | 37 | m_chip_enable = 0; |
phonemacro | 0:4a3d6ac5042d | 38 | } |
phonemacro | 0:4a3d6ac5042d | 39 | |
phonemacro | 0:4a3d6ac5042d | 40 | int MAX31723::write_reg(uint8_t val, uint8_t reg) |
phonemacro | 0:4a3d6ac5042d | 41 | { |
phonemacro | 0:4a3d6ac5042d | 42 | |
phonemacro | 0:4a3d6ac5042d | 43 | m_chip_enable = 1; |
phonemacro | 0:4a3d6ac5042d | 44 | m_spi.write(reg); |
phonemacro | 0:4a3d6ac5042d | 45 | m_spi.write(val); |
phonemacro | 0:4a3d6ac5042d | 46 | m_chip_enable = 0; |
phonemacro | 0:4a3d6ac5042d | 47 | return MAX31723_NO_ERROR; |
phonemacro | 0:4a3d6ac5042d | 48 | } |
phonemacro | 0:4a3d6ac5042d | 49 | |
phonemacro | 0:4a3d6ac5042d | 50 | int MAX31723::read_reg(uint8_t &val, uint8_t reg) |
phonemacro | 0:4a3d6ac5042d | 51 | { |
phonemacro | 0:4a3d6ac5042d | 52 | |
phonemacro | 0:4a3d6ac5042d | 53 | m_chip_enable = 1; |
phonemacro | 0:4a3d6ac5042d | 54 | m_spi.write(reg); |
phonemacro | 0:4a3d6ac5042d | 55 | val = m_spi.write(0); |
phonemacro | 0:4a3d6ac5042d | 56 | m_chip_enable = 0; |
phonemacro | 0:4a3d6ac5042d | 57 | return MAX31723_NO_ERROR; |
phonemacro | 0:4a3d6ac5042d | 58 | } |
phonemacro | 0:4a3d6ac5042d | 59 | |
phonemacro | 0:4a3d6ac5042d | 60 | int MAX31723::perform_one_shot(uint8_t resolution) |
phonemacro | 0:4a3d6ac5042d | 61 | { |
phonemacro | 0:4a3d6ac5042d | 62 | if (resolution <= MAX31723_CFG_RESOLUTION_12BIT) |
phonemacro | 0:4a3d6ac5042d | 63 | write_reg(resolution | MAX31723_CFG_1SHOT | MAX31723_CFG_STANDBY, |
phonemacro | 0:4a3d6ac5042d | 64 | MAX31723_REG_CFG | MAX31723_WRITE_MASK); |
phonemacro | 0:4a3d6ac5042d | 65 | else |
phonemacro | 0:4a3d6ac5042d | 66 | return MAX31723_ERROR; |
phonemacro | 0:4a3d6ac5042d | 67 | return MAX31723_NO_ERROR; |
phonemacro | 0:4a3d6ac5042d | 68 | } |
phonemacro | 0:4a3d6ac5042d | 69 | |
phonemacro | 0:4a3d6ac5042d | 70 | float MAX31723::read_temp() |
phonemacro | 0:4a3d6ac5042d | 71 | { |
phonemacro | 0:4a3d6ac5042d | 72 | uint8_t lsb, msb; |
phonemacro | 0:4a3d6ac5042d | 73 | uint16_t raw_temp; |
phonemacro | 0:4a3d6ac5042d | 74 | float temperature; |
phonemacro | 0:4a3d6ac5042d | 75 | |
phonemacro | 0:4a3d6ac5042d | 76 | read_reg(lsb, MAX31723_REG_TEMP_LSB); |
phonemacro | 0:4a3d6ac5042d | 77 | read_reg(msb, MAX31723_REG_TEMP_MSB); |
phonemacro | 0:4a3d6ac5042d | 78 | |
phonemacro | 0:4a3d6ac5042d | 79 | raw_temp = int16_t((msb << 8) | (lsb)); |
phonemacro | 0:4a3d6ac5042d | 80 | raw_temp = raw_temp >> 4; |
phonemacro | 0:4a3d6ac5042d | 81 | temperature = raw_temp * 0.0625 ; |
phonemacro | 0:4a3d6ac5042d | 82 | return temperature; |
phonemacro | 0:4a3d6ac5042d | 83 | } |
phonemacro | 0:4a3d6ac5042d | 84 | |
phonemacro | 0:4a3d6ac5042d | 85 | |
phonemacro | 0:4a3d6ac5042d | 86 | float MAX31723::celsius_to_fahrenheit(float temp_c) |
phonemacro | 0:4a3d6ac5042d | 87 | { |
phonemacro | 0:4a3d6ac5042d | 88 | float temp_f; |
phonemacro | 0:4a3d6ac5042d | 89 | temp_f = ((temp_c * 9)/5) + 32; |
phonemacro | 0:4a3d6ac5042d | 90 | return temp_f; |
phonemacro | 0:4a3d6ac5042d | 91 | } |
phonemacro | 0:4a3d6ac5042d | 92 | |
phonemacro | 0:4a3d6ac5042d | 93 | MAX31723::~MAX31723(void) |
phonemacro | 0:4a3d6ac5042d | 94 | { |
phonemacro | 0:4a3d6ac5042d | 95 | //empty block |
phonemacro | 0:4a3d6ac5042d | 96 | } |
phonemacro | 0:4a3d6ac5042d | 97 |