Roy van Dam
Humidity and Temperature Sensor - Sensirion SHT1x driver
Dependents: ProgrammePrincipal Wetterstation project1 4180_Project ... more
sht15.hpp@0:d55659b0c4a0, 2010-11-18 (annotated)
- Committer:
- NegativeBlack
- Date:
- Thu Nov 18 10:23:43 2010 +0000
- Revision:
- 0:d55659b0c4a0
- Child:
- 1:8465801be23f
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| NegativeBlack | 0:d55659b0c4a0 | 1 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 2 | * Copyright (c) 2010 Roy van Dam <roy@negative-black.org> |
| NegativeBlack | 0:d55659b0c4a0 | 3 | * All rights reserved. |
| NegativeBlack | 0:d55659b0c4a0 | 4 | * |
| NegativeBlack | 0:d55659b0c4a0 | 5 | * Redistribution and use in source and binary forms, with or without |
| NegativeBlack | 0:d55659b0c4a0 | 6 | * modification, are permitted provided that the following conditions |
| NegativeBlack | 0:d55659b0c4a0 | 7 | * are met: |
| NegativeBlack | 0:d55659b0c4a0 | 8 | * 1. Redistributions of source code must retain the above copyright |
| NegativeBlack | 0:d55659b0c4a0 | 9 | * notice, this list of conditions and the following disclaimer. |
| NegativeBlack | 0:d55659b0c4a0 | 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| NegativeBlack | 0:d55659b0c4a0 | 11 | * notice, this list of conditions and the following disclaimer in the |
| NegativeBlack | 0:d55659b0c4a0 | 12 | * documentation and/or other materials provided with the distribution. |
| NegativeBlack | 0:d55659b0c4a0 | 13 | * |
| NegativeBlack | 0:d55659b0c4a0 | 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| NegativeBlack | 0:d55659b0c4a0 | 15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| NegativeBlack | 0:d55659b0c4a0 | 16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| NegativeBlack | 0:d55659b0c4a0 | 17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| NegativeBlack | 0:d55659b0c4a0 | 18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| NegativeBlack | 0:d55659b0c4a0 | 19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| NegativeBlack | 0:d55659b0c4a0 | 20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| NegativeBlack | 0:d55659b0c4a0 | 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| NegativeBlack | 0:d55659b0c4a0 | 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| NegativeBlack | 0:d55659b0c4a0 | 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| NegativeBlack | 0:d55659b0c4a0 | 24 | * SUCH DAMAGE. |
| NegativeBlack | 0:d55659b0c4a0 | 25 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 26 | |
| NegativeBlack | 0:d55659b0c4a0 | 27 | #ifndef _SHT15_HPP_ |
| NegativeBlack | 0:d55659b0c4a0 | 28 | #define _SHT15_HPP_ |
| NegativeBlack | 0:d55659b0c4a0 | 29 | |
| NegativeBlack | 0:d55659b0c4a0 | 30 | #include "mbed.h" |
| NegativeBlack | 0:d55659b0c4a0 | 31 | #include "i2c.hpp" |
| NegativeBlack | 0:d55659b0c4a0 | 32 | |
| NegativeBlack | 0:d55659b0c4a0 | 33 | namespace SHTx { |
| NegativeBlack | 0:d55659b0c4a0 | 34 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 35 | * Class: SHT15 |
| NegativeBlack | 0:d55659b0c4a0 | 36 | * Humidity and Temperature Sensor - SHT15 |
| NegativeBlack | 0:d55659b0c4a0 | 37 | * High level software interface. |
| NegativeBlack | 0:d55659b0c4a0 | 38 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 39 | class SHT15 { |
| NegativeBlack | 0:d55659b0c4a0 | 40 | private: |
| NegativeBlack | 0:d55659b0c4a0 | 41 | I2C i2c; |
| NegativeBlack | 0:d55659b0c4a0 | 42 | |
| NegativeBlack | 0:d55659b0c4a0 | 43 | bool ready; |
| NegativeBlack | 0:d55659b0c4a0 | 44 | bool scale; |
| NegativeBlack | 0:d55659b0c4a0 | 45 | |
| NegativeBlack | 0:d55659b0c4a0 | 46 | uint8_t status_register; |
| NegativeBlack | 0:d55659b0c4a0 | 47 | uint16_t humidity; |
| NegativeBlack | 0:d55659b0c4a0 | 48 | uint16_t temperature; |
| NegativeBlack | 0:d55659b0c4a0 | 49 | |
| NegativeBlack | 0:d55659b0c4a0 | 50 | struct coefficients { |
| NegativeBlack | 0:d55659b0c4a0 | 51 | // Humidity conversion coefficients |
| NegativeBlack | 0:d55659b0c4a0 | 52 | float c1[2], c2[2], c3[2]; |
| NegativeBlack | 0:d55659b0c4a0 | 53 | |
| NegativeBlack | 0:d55659b0c4a0 | 54 | // Temperature conversion coefficients |
| NegativeBlack | 0:d55659b0c4a0 | 55 | float dc[2], df[2], dv[2]; |
| NegativeBlack | 0:d55659b0c4a0 | 56 | |
| NegativeBlack | 0:d55659b0c4a0 | 57 | // Temperature compensation coefficients |
| NegativeBlack | 0:d55659b0c4a0 | 58 | float t1[2], t2[2]; |
| NegativeBlack | 0:d55659b0c4a0 | 59 | |
| NegativeBlack | 0:d55659b0c4a0 | 60 | // Initialize table |
| NegativeBlack | 0:d55659b0c4a0 | 61 | coefficients(void) { |
| NegativeBlack | 0:d55659b0c4a0 | 62 | c1[0] = -2.046f; c2[1] = -2.046f; |
| NegativeBlack | 0:d55659b0c4a0 | 63 | c2[0] = 0.036f; c2[1] = 0.587f; |
| NegativeBlack | 0:d55659b0c4a0 | 64 | c3[0] = -0.0000015955f; c2[1] = -0.00040845f; |
| NegativeBlack | 0:d55659b0c4a0 | 65 | |
| NegativeBlack | 0:d55659b0c4a0 | 66 | dc[0] = 0.01f; dc[1] = 0.04f; |
| NegativeBlack | 0:d55659b0c4a0 | 67 | df[0] = 0.018f; df[1] = 0.072f; |
| NegativeBlack | 0:d55659b0c4a0 | 68 | dv[0] = -39.7f; dv[1] = -39.5f; |
| NegativeBlack | 0:d55659b0c4a0 | 69 | |
| NegativeBlack | 0:d55659b0c4a0 | 70 | t1[0] = 0.01f; t1[1] = 0.01f; |
| NegativeBlack | 0:d55659b0c4a0 | 71 | t2[0] = 0.00008f; t2[1] = 0.00128f; |
| NegativeBlack | 0:d55659b0c4a0 | 72 | }; |
| NegativeBlack | 0:d55659b0c4a0 | 73 | } coefficient; |
| NegativeBlack | 0:d55659b0c4a0 | 74 | |
| NegativeBlack | 0:d55659b0c4a0 | 75 | enum cmd_list { |
| NegativeBlack | 0:d55659b0c4a0 | 76 | cmd_read_temperature = 0x03, |
| NegativeBlack | 0:d55659b0c4a0 | 77 | cmd_read_humidity = 0x05, |
| NegativeBlack | 0:d55659b0c4a0 | 78 | cmd_read_register = 0x07, |
| NegativeBlack | 0:d55659b0c4a0 | 79 | cmd_write_register = 0x06, |
| NegativeBlack | 0:d55659b0c4a0 | 80 | cmd_reset_device = 0x1E |
| NegativeBlack | 0:d55659b0c4a0 | 81 | }; |
| NegativeBlack | 0:d55659b0c4a0 | 82 | |
| NegativeBlack | 0:d55659b0c4a0 | 83 | enum flag_list { |
| NegativeBlack | 0:d55659b0c4a0 | 84 | flag_resolution = 0x01, |
| NegativeBlack | 0:d55659b0c4a0 | 85 | flag_reset = 0x02, |
| NegativeBlack | 0:d55659b0c4a0 | 86 | flag_heater = 0x04, |
| NegativeBlack | 0:d55659b0c4a0 | 87 | flag_battery = 0x40 |
| NegativeBlack | 0:d55659b0c4a0 | 88 | }; |
| NegativeBlack | 0:d55659b0c4a0 | 89 | |
| NegativeBlack | 0:d55659b0c4a0 | 90 | public: |
| NegativeBlack | 0:d55659b0c4a0 | 91 | /* |
| NegativeBlack | 0:d55659b0c4a0 | 92 | * Initializes I2C interface and waits |
| NegativeBlack | 0:d55659b0c4a0 | 93 | * the 11ms device initialization time. |
| NegativeBlack | 0:d55659b0c4a0 | 94 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 95 | SHT15(PinName sda, PinName scl); |
| NegativeBlack | 0:d55659b0c4a0 | 96 | |
| NegativeBlack | 0:d55659b0c4a0 | 97 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 98 | * Function: getTemperature |
| NegativeBlack | 0:d55659b0c4a0 | 99 | * Returns the current temperature. |
| NegativeBlack | 0:d55659b0c4a0 | 100 | * |
| NegativeBlack | 0:d55659b0c4a0 | 101 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 102 | * returns - current temperature. |
| NegativeBlack | 0:d55659b0c4a0 | 103 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 104 | float getTemperature(void); |
| NegativeBlack | 0:d55659b0c4a0 | 105 | |
| NegativeBlack | 0:d55659b0c4a0 | 106 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 107 | * Function: getHumidity |
| NegativeBlack | 0:d55659b0c4a0 | 108 | * Returns the current relative humidity. |
| NegativeBlack | 0:d55659b0c4a0 | 109 | * |
| NegativeBlack | 0:d55659b0c4a0 | 110 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 111 | * returns - relative humidity. |
| NegativeBlack | 0:d55659b0c4a0 | 112 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 113 | float getHumidity(void); |
| NegativeBlack | 0:d55659b0c4a0 | 114 | |
| NegativeBlack | 0:d55659b0c4a0 | 115 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 116 | * Function: checkBattery |
| NegativeBlack | 0:d55659b0c4a0 | 117 | * Returns true if battery voltage drops |
| NegativeBlack | 0:d55659b0c4a0 | 118 | * below 2.4 volt. |
| NegativeBlack | 0:d55659b0c4a0 | 119 | * |
| NegativeBlack | 0:d55659b0c4a0 | 120 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 121 | * returns - true on low battery, false otherwise |
| NegativeBlack | 0:d55659b0c4a0 | 122 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 123 | bool checkBattery(void); |
| NegativeBlack | 0:d55659b0c4a0 | 124 | |
| NegativeBlack | 0:d55659b0c4a0 | 125 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 126 | * Function: setHeater |
| NegativeBlack | 0:d55659b0c4a0 | 127 | * Enable on chip heating element. The heater may |
| NegativeBlack | 0:d55659b0c4a0 | 128 | * increase the temperature of the sensor by 5C to |
| NegativeBlack | 0:d55659b0c4a0 | 129 | * 10C beyond ambient temperature. |
| NegativeBlack | 0:d55659b0c4a0 | 130 | * |
| NegativeBlack | 0:d55659b0c4a0 | 131 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 132 | * value - true->on, false->off |
| NegativeBlack | 0:d55659b0c4a0 | 133 | * return - operation result |
| NegativeBlack | 0:d55659b0c4a0 | 134 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 135 | bool setHeater(bool value); |
| NegativeBlack | 0:d55659b0c4a0 | 136 | |
| NegativeBlack | 0:d55659b0c4a0 | 137 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 138 | * Function: setResolution |
| NegativeBlack | 0:d55659b0c4a0 | 139 | * Set lower measurement resolution to allow |
| NegativeBlack | 0:d55659b0c4a0 | 140 | * faster update frequencies. |
| NegativeBlack | 0:d55659b0c4a0 | 141 | * |
| NegativeBlack | 0:d55659b0c4a0 | 142 | * Resolutions |
| NegativeBlack | 0:d55659b0c4a0 | 143 | * low: 8bit humid. - 12bit temp. |
| NegativeBlack | 0:d55659b0c4a0 | 144 | * high: 12bit humid. - 14bit temp. |
| NegativeBlack | 0:d55659b0c4a0 | 145 | * |
| NegativeBlack | 0:d55659b0c4a0 | 146 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 147 | * value - true->low, false->high |
| NegativeBlack | 0:d55659b0c4a0 | 148 | * return - operation result |
| NegativeBlack | 0:d55659b0c4a0 | 149 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 150 | bool setResolution(bool value); |
| NegativeBlack | 0:d55659b0c4a0 | 151 | |
| NegativeBlack | 0:d55659b0c4a0 | 152 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 153 | * Function: setScale |
| NegativeBlack | 0:d55659b0c4a0 | 154 | * Sets output scale to fahrenheit or celcius. |
| NegativeBlack | 0:d55659b0c4a0 | 155 | * |
| NegativeBlack | 0:d55659b0c4a0 | 156 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 157 | * value - true->fahrenheit, false->celcius |
| NegativeBlack | 0:d55659b0c4a0 | 158 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 159 | void setScale(bool value); |
| NegativeBlack | 0:d55659b0c4a0 | 160 | |
| NegativeBlack | 0:d55659b0c4a0 | 161 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 162 | * Function: update |
| NegativeBlack | 0:d55659b0c4a0 | 163 | * Performs humidity and temperature |
| NegativeBlack | 0:d55659b0c4a0 | 164 | * sensor readout of the chip. |
| NegativeBlack | 0:d55659b0c4a0 | 165 | * |
| NegativeBlack | 0:d55659b0c4a0 | 166 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 167 | * return - operation result |
| NegativeBlack | 0:d55659b0c4a0 | 168 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 169 | bool update(void); |
| NegativeBlack | 0:d55659b0c4a0 | 170 | |
| NegativeBlack | 0:d55659b0c4a0 | 171 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 172 | * Function: reset |
| NegativeBlack | 0:d55659b0c4a0 | 173 | * Performs full chip reset. |
| NegativeBlack | 0:d55659b0c4a0 | 174 | * |
| NegativeBlack | 0:d55659b0c4a0 | 175 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 176 | * return - operation result |
| NegativeBlack | 0:d55659b0c4a0 | 177 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 178 | bool reset(void); |
| NegativeBlack | 0:d55659b0c4a0 | 179 | |
| NegativeBlack | 0:d55659b0c4a0 | 180 | private: |
| NegativeBlack | 0:d55659b0c4a0 | 181 | |
| NegativeBlack | 0:d55659b0c4a0 | 182 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 183 | * Function: convertTemperature |
| NegativeBlack | 0:d55659b0c4a0 | 184 | * Convert sensor data to human readable value |
| NegativeBlack | 0:d55659b0c4a0 | 185 | * on the farenheit or celcius scale. |
| NegativeBlack | 0:d55659b0c4a0 | 186 | * |
| NegativeBlack | 0:d55659b0c4a0 | 187 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 188 | * sot - raw temperatue sensor output |
| NegativeBlack | 0:d55659b0c4a0 | 189 | * res - true->low, false->high |
| NegativeBlack | 0:d55659b0c4a0 | 190 | * scale - true->fahrenheit, false->celcius |
| NegativeBlack | 0:d55659b0c4a0 | 191 | * return - temperature |
| NegativeBlack | 0:d55659b0c4a0 | 192 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 193 | float convertTemperature(uint16_t sot, bool res = false, bool scale = false); |
| NegativeBlack | 0:d55659b0c4a0 | 194 | |
| NegativeBlack | 0:d55659b0c4a0 | 195 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 196 | * Function: convertHumidity |
| NegativeBlack | 0:d55659b0c4a0 | 197 | * Convert sensor data to relative humidity |
| NegativeBlack | 0:d55659b0c4a0 | 198 | * in percentage. |
| NegativeBlack | 0:d55659b0c4a0 | 199 | * |
| NegativeBlack | 0:d55659b0c4a0 | 200 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 201 | * sohr - raw humidity sensor output |
| NegativeBlack | 0:d55659b0c4a0 | 202 | * sot - raw temperatue sensor output |
| NegativeBlack | 0:d55659b0c4a0 | 203 | * res - true->low, false->high |
| NegativeBlack | 0:d55659b0c4a0 | 204 | * return - relative humidity |
| NegativeBlack | 0:d55659b0c4a0 | 205 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 206 | float convertHumidity(uint16_t sohr, uint16_t sot, bool res = false); |
| NegativeBlack | 0:d55659b0c4a0 | 207 | |
| NegativeBlack | 0:d55659b0c4a0 | 208 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 209 | * Function: writeRegister |
| NegativeBlack | 0:d55659b0c4a0 | 210 | * Write internal chip register. |
| NegativeBlack | 0:d55659b0c4a0 | 211 | * |
| NegativeBlack | 0:d55659b0c4a0 | 212 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 213 | * return - operation result |
| NegativeBlack | 0:d55659b0c4a0 | 214 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 215 | bool writeRegister(void); |
| NegativeBlack | 0:d55659b0c4a0 | 216 | |
| NegativeBlack | 0:d55659b0c4a0 | 217 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 218 | * Function: readRegister |
| NegativeBlack | 0:d55659b0c4a0 | 219 | * Reads internal chip register |
| NegativeBlack | 0:d55659b0c4a0 | 220 | * |
| NegativeBlack | 0:d55659b0c4a0 | 221 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 222 | * command - register to be accessed |
| NegativeBlack | 0:d55659b0c4a0 | 223 | * return - operation result |
| NegativeBlack | 0:d55659b0c4a0 | 224 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 225 | bool readRegister(cmd_list command); |
| NegativeBlack | 0:d55659b0c4a0 | 226 | |
| NegativeBlack | 0:d55659b0c4a0 | 227 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 228 | * Function: setFlag |
| NegativeBlack | 0:d55659b0c4a0 | 229 | * Modify local register flag. |
| NegativeBlack | 0:d55659b0c4a0 | 230 | * |
| NegativeBlack | 0:d55659b0c4a0 | 231 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 232 | * flag - flag to be modified |
| NegativeBlack | 0:d55659b0c4a0 | 233 | * value - value to be assigned |
| NegativeBlack | 0:d55659b0c4a0 | 234 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 235 | void setFlag(flag_list flag, bool value); |
| NegativeBlack | 0:d55659b0c4a0 | 236 | |
| NegativeBlack | 0:d55659b0c4a0 | 237 | /** |
| NegativeBlack | 0:d55659b0c4a0 | 238 | * Function: getFlag |
| NegativeBlack | 0:d55659b0c4a0 | 239 | * Get local register flag. |
| NegativeBlack | 0:d55659b0c4a0 | 240 | * |
| NegativeBlack | 0:d55659b0c4a0 | 241 | * Values: |
| NegativeBlack | 0:d55659b0c4a0 | 242 | * returns - flag value |
| NegativeBlack | 0:d55659b0c4a0 | 243 | */ |
| NegativeBlack | 0:d55659b0c4a0 | 244 | bool getFlag(flag_list flag); |
| NegativeBlack | 0:d55659b0c4a0 | 245 | }; |
| NegativeBlack | 0:d55659b0c4a0 | 246 | } |
| NegativeBlack | 0:d55659b0c4a0 | 247 | |
| NegativeBlack | 0:d55659b0c4a0 | 248 | /* !_SHT15_HPP_ */ |
| NegativeBlack | 0:d55659b0c4a0 | 249 | #endif |