CN0357 toxic gas measurement sensor
For additional information check out the mbed page of the Analog Devices wiki: https://wiki.analog.com/resources/tools-software/mbed-drivers-all
CN0357.cpp@1:19e1bf69dc75, 2016-05-19 (annotated)
- Committer:
- adisuciu
- Date:
- Thu May 19 08:46:59 2016 +0000
- Revision:
- 1:19e1bf69dc75
- Parent:
- 0:db2cdeb6928a
Added library dependencies
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
adisuciu | 0:db2cdeb6928a | 1 | /** |
adisuciu | 0:db2cdeb6928a | 2 | * @file cn0357.cpp |
adisuciu | 0:db2cdeb6928a | 3 | * @brief Source file for CN0357 |
adisuciu | 0:db2cdeb6928a | 4 | * @author Analog Devices Inc. |
adisuciu | 0:db2cdeb6928a | 5 | * |
adisuciu | 0:db2cdeb6928a | 6 | * For support please go to: |
adisuciu | 0:db2cdeb6928a | 7 | * Github: https://github.com/analogdevicesinc/mbed-adi |
adisuciu | 0:db2cdeb6928a | 8 | * Support: https://ez.analog.com/community/linux-device-drivers/microcontroller-no-os-drivers |
adisuciu | 0:db2cdeb6928a | 9 | * Product: www.analog.com/EVAL-CN0357-ARDZ |
adisuciu | 0:db2cdeb6928a | 10 | * More: https://wiki.analog.com/resources/tools-software/mbed-drivers-all |
adisuciu | 0:db2cdeb6928a | 11 | |
adisuciu | 0:db2cdeb6928a | 12 | ******************************************************************************** |
adisuciu | 0:db2cdeb6928a | 13 | * Copyright 2016(c) Analog Devices, Inc. |
adisuciu | 0:db2cdeb6928a | 14 | * |
adisuciu | 0:db2cdeb6928a | 15 | * All rights reserved. |
adisuciu | 0:db2cdeb6928a | 16 | * |
adisuciu | 0:db2cdeb6928a | 17 | * Redistribution and use in source and binary forms, with or without |
adisuciu | 0:db2cdeb6928a | 18 | * modification, are permitted provided that the following conditions are met: |
adisuciu | 0:db2cdeb6928a | 19 | * - Redistributions of source code must retain the above copyright |
adisuciu | 0:db2cdeb6928a | 20 | * notice, this list of conditions and the following disclaimer. |
adisuciu | 0:db2cdeb6928a | 21 | * - Redistributions in binary form must reproduce the above copyright |
adisuciu | 0:db2cdeb6928a | 22 | * notice, this list of conditions and the following disclaimer in |
adisuciu | 0:db2cdeb6928a | 23 | * the documentation and/or other materials provided with the |
adisuciu | 0:db2cdeb6928a | 24 | * distribution. |
adisuciu | 0:db2cdeb6928a | 25 | * - Neither the name of Analog Devices, Inc. nor the names of its |
adisuciu | 0:db2cdeb6928a | 26 | * contributors may be used to endorse or promote products derived |
adisuciu | 0:db2cdeb6928a | 27 | * from this software without specific prior written permission. |
adisuciu | 0:db2cdeb6928a | 28 | * - The use of this software may or may not infringe the patent rights |
adisuciu | 0:db2cdeb6928a | 29 | * of one or more patent holders. This license does not release you |
adisuciu | 0:db2cdeb6928a | 30 | * from the requirement that you obtain separate licenses from these |
adisuciu | 0:db2cdeb6928a | 31 | * patent holders to use this software. |
adisuciu | 0:db2cdeb6928a | 32 | * - Use of the software either in source or binary form, must be run |
adisuciu | 0:db2cdeb6928a | 33 | * on or directly connected to an Analog Devices Inc. component. |
adisuciu | 0:db2cdeb6928a | 34 | * |
adisuciu | 0:db2cdeb6928a | 35 | * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR |
adisuciu | 0:db2cdeb6928a | 36 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, |
adisuciu | 0:db2cdeb6928a | 37 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
adisuciu | 0:db2cdeb6928a | 38 | * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, |
adisuciu | 0:db2cdeb6928a | 39 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
adisuciu | 0:db2cdeb6928a | 40 | * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR |
adisuciu | 0:db2cdeb6928a | 41 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
adisuciu | 0:db2cdeb6928a | 42 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
adisuciu | 0:db2cdeb6928a | 43 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
adisuciu | 0:db2cdeb6928a | 44 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
adisuciu | 0:db2cdeb6928a | 45 | * |
adisuciu | 0:db2cdeb6928a | 46 | ********************************************************************************/ |
adisuciu | 0:db2cdeb6928a | 47 | |
adisuciu | 0:db2cdeb6928a | 48 | #include "mbed.h" |
adisuciu | 0:db2cdeb6928a | 49 | #include "AD7790.h" |
adisuciu | 0:db2cdeb6928a | 50 | #include "AD5270.h" |
adisuciu | 0:db2cdeb6928a | 51 | #include "CN0357.h" |
adisuciu | 0:db2cdeb6928a | 52 | |
adisuciu | 0:db2cdeb6928a | 53 | /** |
adisuciu | 0:db2cdeb6928a | 54 | * @brief CN0357 constructor |
adisuciu | 0:db2cdeb6928a | 55 | * @param CSAD7790 - (optional)chip select of the AD7790 |
adisuciu | 0:db2cdeb6928a | 56 | * @param CSAD5270 - (optional)chip select of the AD5270 |
adisuciu | 0:db2cdeb6928a | 57 | * @param MOSI - (optional)pin of the SPI interface |
adisuciu | 0:db2cdeb6928a | 58 | * @param MISO - (optional)pin of the SPI interface |
adisuciu | 0:db2cdeb6928a | 59 | * @param SCK - (optional)pin of the SPI interface |
adisuciu | 0:db2cdeb6928a | 60 | */ |
adisuciu | 0:db2cdeb6928a | 61 | CN0357::CN0357(PinName CSAD7790, PinName CSAD5270, PinName MOSI, PinName MISO, |
adisuciu | 0:db2cdeb6928a | 62 | PinName SCK) : |
adisuciu | 0:db2cdeb6928a | 63 | _vref(1.2), _sensor_sensitivity(0), _sensor_range(0), _RDACvalue(0), |
adisuciu | 0:db2cdeb6928a | 64 | ad7790(_vref, CSAD7790, MOSI, MISO, SCK), ad5270(CSAD5270, 20000.0, MOSI, MISO, SCK) |
adisuciu | 0:db2cdeb6928a | 65 | |
adisuciu | 0:db2cdeb6928a | 66 | { |
adisuciu | 0:db2cdeb6928a | 67 | } |
adisuciu | 0:db2cdeb6928a | 68 | |
adisuciu | 0:db2cdeb6928a | 69 | /** |
adisuciu | 0:db2cdeb6928a | 70 | * @brief initializes the AD7790 and the AD5270 |
adisuciu | 0:db2cdeb6928a | 71 | * @param range - range of the sensor used (in ppm) |
adisuciu | 0:db2cdeb6928a | 72 | * @param sensitivity - sensitivity of the sensor (A/ppm) |
adisuciu | 0:db2cdeb6928a | 73 | * @param jp - (optional)jumper configuration of the CN0357 |
adisuciu | 0:db2cdeb6928a | 74 | * @param mode_val - (optional)if jp is set to InternalADC, configures the mode register of the Internal ADC |
adisuciu | 0:db2cdeb6928a | 75 | * @param filter_val - (optional)if jp is set to InternalADC, configures the filter register of the Internal ADC |
adisuciu | 0:db2cdeb6928a | 76 | */ |
adisuciu | 0:db2cdeb6928a | 77 | void CN0357::init(float range, float sensitivity, JumperConfig_t jp, uint8_t mode_val, uint8_t filter_val) |
adisuciu | 0:db2cdeb6928a | 78 | { |
adisuciu | 0:db2cdeb6928a | 79 | ad5270.frequency(500000); |
adisuciu | 0:db2cdeb6928a | 80 | ad7790.frequency(500000); |
adisuciu | 0:db2cdeb6928a | 81 | |
adisuciu | 0:db2cdeb6928a | 82 | float resistance = set_sensor_parameters(range, sensitivity); |
adisuciu | 0:db2cdeb6928a | 83 | |
adisuciu | 0:db2cdeb6928a | 84 | if(jp == INTERNAL_AD7790) { |
adisuciu | 0:db2cdeb6928a | 85 | _AD7790_init(mode_val, filter_val); |
adisuciu | 0:db2cdeb6928a | 86 | } |
adisuciu | 0:db2cdeb6928a | 87 | _rdac_init(resistance); |
adisuciu | 0:db2cdeb6928a | 88 | } |
adisuciu | 0:db2cdeb6928a | 89 | |
adisuciu | 0:db2cdeb6928a | 90 | /** |
adisuciu | 0:db2cdeb6928a | 91 | * @brief initializes the RDAC and sets SDO to HiZ |
adisuciu | 0:db2cdeb6928a | 92 | * @param resistance - resistance value to initialize the RDAC |
adisuciu | 0:db2cdeb6928a | 93 | * @return |
adisuciu | 0:db2cdeb6928a | 94 | */ |
adisuciu | 0:db2cdeb6928a | 95 | void CN0357::_rdac_init(float resistance) |
adisuciu | 0:db2cdeb6928a | 96 | { |
adisuciu | 0:db2cdeb6928a | 97 | /* RDAC initialization*/ |
adisuciu | 0:db2cdeb6928a | 98 | /* Compute for the nearest RDAC value from given resistance and save data to the structure */ |
adisuciu | 0:db2cdeb6928a | 99 | set_RDAC_value(resistance); |
adisuciu | 0:db2cdeb6928a | 100 | /* Set AD5270 SDO to Hi-Z */ |
adisuciu | 0:db2cdeb6928a | 101 | ad5270.set_SDO_HiZ(); |
adisuciu | 0:db2cdeb6928a | 102 | } |
adisuciu | 0:db2cdeb6928a | 103 | |
adisuciu | 0:db2cdeb6928a | 104 | /** |
adisuciu | 0:db2cdeb6928a | 105 | * @brief initializes the AD7790 |
adisuciu | 0:db2cdeb6928a | 106 | * @param mode_val - configures the mode register of the Internal ADC |
adisuciu | 0:db2cdeb6928a | 107 | * @param filter_val - configures the filter register of the Internal ADC |
adisuciu | 0:db2cdeb6928a | 108 | */ |
adisuciu | 0:db2cdeb6928a | 109 | void CN0357::_AD7790_init(uint8_t mode_val, uint8_t filter_val) |
adisuciu | 0:db2cdeb6928a | 110 | { |
adisuciu | 0:db2cdeb6928a | 111 | ad7790.reset(); |
adisuciu | 0:db2cdeb6928a | 112 | wait_ms(50); |
adisuciu | 0:db2cdeb6928a | 113 | |
adisuciu | 0:db2cdeb6928a | 114 | ad7790.write_mode_reg(mode_val); |
adisuciu | 0:db2cdeb6928a | 115 | wait_us(2); |
adisuciu | 0:db2cdeb6928a | 116 | |
adisuciu | 0:db2cdeb6928a | 117 | ad7790.write_filter_reg(filter_val); |
adisuciu | 0:db2cdeb6928a | 118 | wait_ms(50); |
adisuciu | 0:db2cdeb6928a | 119 | } |
adisuciu | 0:db2cdeb6928a | 120 | |
adisuciu | 0:db2cdeb6928a | 121 | /** |
adisuciu | 0:db2cdeb6928a | 122 | * @brief reads the status register of the AD7790 |
adisuciu | 0:db2cdeb6928a | 123 | * @return status register value |
adisuciu | 0:db2cdeb6928a | 124 | */ |
adisuciu | 0:db2cdeb6928a | 125 | uint8_t CN0357::read_adc_status(void) |
adisuciu | 0:db2cdeb6928a | 126 | { |
adisuciu | 0:db2cdeb6928a | 127 | return ad7790.read_status_reg(); |
adisuciu | 0:db2cdeb6928a | 128 | } |
adisuciu | 0:db2cdeb6928a | 129 | |
adisuciu | 0:db2cdeb6928a | 130 | /** |
adisuciu | 0:db2cdeb6928a | 131 | * @brief reads the ADC and computes the sensor voltage |
adisuciu | 0:db2cdeb6928a | 132 | * @return sensor voltage |
adisuciu | 0:db2cdeb6928a | 133 | */ |
adisuciu | 0:db2cdeb6928a | 134 | float CN0357::read_sensor_voltage(void) |
adisuciu | 0:db2cdeb6928a | 135 | { |
adisuciu | 0:db2cdeb6928a | 136 | return ad7790.read_voltage(); |
adisuciu | 0:db2cdeb6928a | 137 | } |
adisuciu | 0:db2cdeb6928a | 138 | |
adisuciu | 0:db2cdeb6928a | 139 | /** |
adisuciu | 0:db2cdeb6928a | 140 | * @brief reads the data register of the AD7790 |
adisuciu | 0:db2cdeb6928a | 141 | * @return data register value |
adisuciu | 0:db2cdeb6928a | 142 | */ |
adisuciu | 0:db2cdeb6928a | 143 | uint16_t CN0357::read_sensor(void) |
adisuciu | 0:db2cdeb6928a | 144 | { |
adisuciu | 0:db2cdeb6928a | 145 | return ad7790.read_u16(); |
adisuciu | 0:db2cdeb6928a | 146 | } |
adisuciu | 0:db2cdeb6928a | 147 | |
adisuciu | 0:db2cdeb6928a | 148 | /** |
adisuciu | 0:db2cdeb6928a | 149 | * @brief reads and computes the sensor reading in PPM |
adisuciu | 0:db2cdeb6928a | 150 | * @return value of the sensor reading in PPM |
adisuciu | 0:db2cdeb6928a | 151 | */ |
adisuciu | 0:db2cdeb6928a | 152 | float CN0357::read_ppm() |
adisuciu | 0:db2cdeb6928a | 153 | { |
adisuciu | 0:db2cdeb6928a | 154 | return calc_ppm(ad7790.read_voltage()); /* Convert voltage to Gas concentration*/ |
adisuciu | 0:db2cdeb6928a | 155 | } |
adisuciu | 0:db2cdeb6928a | 156 | |
adisuciu | 0:db2cdeb6928a | 157 | /** |
adisuciu | 0:db2cdeb6928a | 158 | * @brief computes a value in PPM from a reading received as a param |
adisuciu | 0:db2cdeb6928a | 159 | * @param adcVoltage - voltage to be converted to PPM |
adisuciu | 0:db2cdeb6928a | 160 | * @return sensor value in PPM |
adisuciu | 0:db2cdeb6928a | 161 | */ |
adisuciu | 0:db2cdeb6928a | 162 | float CN0357::calc_ppm(float adcVoltage) |
adisuciu | 0:db2cdeb6928a | 163 | { |
adisuciu | 0:db2cdeb6928a | 164 | float fConcentration = 0; |
adisuciu | 0:db2cdeb6928a | 165 | fConcentration = (fabs(adcVoltage) / _RDACvalue) / _sensor_sensitivity; |
adisuciu | 0:db2cdeb6928a | 166 | return fConcentration; |
adisuciu | 0:db2cdeb6928a | 167 | } |
adisuciu | 0:db2cdeb6928a | 168 | |
adisuciu | 0:db2cdeb6928a | 169 | /** |
adisuciu | 0:db2cdeb6928a | 170 | * @brief computes voltage from a 16 bit ADC value received as a parameter |
adisuciu | 0:db2cdeb6928a | 171 | * @param data - ADC value |
adisuciu | 0:db2cdeb6928a | 172 | * @return sensor voltage |
adisuciu | 0:db2cdeb6928a | 173 | */ |
adisuciu | 0:db2cdeb6928a | 174 | float CN0357::data_to_voltage(uint16_t data) |
adisuciu | 0:db2cdeb6928a | 175 | { |
adisuciu | 0:db2cdeb6928a | 176 | return ad7790.data_to_voltage(data); |
adisuciu | 0:db2cdeb6928a | 177 | } |
adisuciu | 0:db2cdeb6928a | 178 | |
adisuciu | 0:db2cdeb6928a | 179 | /** |
adisuciu | 0:db2cdeb6928a | 180 | * @brief sets a new value for the RDAC |
adisuciu | 0:db2cdeb6928a | 181 | * @param resistance new value for the resistance |
adisuciu | 0:db2cdeb6928a | 182 | * @return none |
adisuciu | 0:db2cdeb6928a | 183 | */ |
adisuciu | 0:db2cdeb6928a | 184 | void CN0357::set_RDAC_value(float resistance) |
adisuciu | 0:db2cdeb6928a | 185 | { |
adisuciu | 0:db2cdeb6928a | 186 | _RDACvalue = ad5270.write_RDAC(resistance); |
adisuciu | 0:db2cdeb6928a | 187 | } |
adisuciu | 0:db2cdeb6928a | 188 | |
adisuciu | 0:db2cdeb6928a | 189 | /** |
adisuciu | 0:db2cdeb6928a | 190 | * @brief getter method for RDAC value |
adisuciu | 0:db2cdeb6928a | 191 | * @return value of the RDAC in ohms |
adisuciu | 0:db2cdeb6928a | 192 | */ |
adisuciu | 0:db2cdeb6928a | 193 | float CN0357::get_RDAC_value() |
adisuciu | 0:db2cdeb6928a | 194 | { |
adisuciu | 0:db2cdeb6928a | 195 | return _RDACvalue; |
adisuciu | 0:db2cdeb6928a | 196 | } |
adisuciu | 0:db2cdeb6928a | 197 | |
adisuciu | 0:db2cdeb6928a | 198 | /** |
adisuciu | 0:db2cdeb6928a | 199 | * @brief set sensor range and sensitivity |
adisuciu | 0:db2cdeb6928a | 200 | * sets sensor range, sensitivity |
adisuciu | 0:db2cdeb6928a | 201 | * returns suggested resistance value for feedback resistor |
adisuciu | 0:db2cdeb6928a | 202 | * @param range - range of the sensor used (in ppm) |
adisuciu | 0:db2cdeb6928a | 203 | * @param sensitivity - sensitivity of the sensor (in A/ppm) |
adisuciu | 0:db2cdeb6928a | 204 | * @return suggested resistance value for feedback resistor |
adisuciu | 0:db2cdeb6928a | 205 | */ |
adisuciu | 0:db2cdeb6928a | 206 | float CN0357::set_sensor_parameters(float range, float sensitivity) |
adisuciu | 0:db2cdeb6928a | 207 | { |
adisuciu | 0:db2cdeb6928a | 208 | _sensor_sensitivity = static_cast<float>(sensitivity); |
adisuciu | 0:db2cdeb6928a | 209 | _sensor_range = range; |
adisuciu | 0:db2cdeb6928a | 210 | return (_vref / (static_cast<float>(_sensor_range * _sensor_sensitivity))); |
adisuciu | 0:db2cdeb6928a | 211 | } |
adisuciu | 0:db2cdeb6928a | 212 | |
adisuciu | 0:db2cdeb6928a | 213 | /** |
adisuciu | 0:db2cdeb6928a | 214 | * @brief getter method for sensor sensitivity |
adisuciu | 0:db2cdeb6928a | 215 | * @return sensor sensitivity (in A/ppm) |
adisuciu | 0:db2cdeb6928a | 216 | */ |
adisuciu | 0:db2cdeb6928a | 217 | float CN0357::get_sensor_sensitivity() |
adisuciu | 0:db2cdeb6928a | 218 | { |
adisuciu | 0:db2cdeb6928a | 219 | return _sensor_sensitivity; |
adisuciu | 0:db2cdeb6928a | 220 | } |
adisuciu | 0:db2cdeb6928a | 221 | |
adisuciu | 0:db2cdeb6928a | 222 | /** |
adisuciu | 0:db2cdeb6928a | 223 | * @brief getter method for sensor range |
adisuciu | 0:db2cdeb6928a | 224 | * @return sensor range (in ppm) |
adisuciu | 0:db2cdeb6928a | 225 | */ |
adisuciu | 0:db2cdeb6928a | 226 | float CN0357::get_sensor_range() |
adisuciu | 0:db2cdeb6928a | 227 | { |
adisuciu | 0:db2cdeb6928a | 228 | return _sensor_range; |
adisuciu | 0:db2cdeb6928a | 229 | } |