Diff: CN0357.cpp

Revision:

0:db2cdeb6928a

diff -r 000000000000 -r db2cdeb6928a CN0357.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CN0357.cpp	Wed May 18 15:18:49 2016 +0000
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+/**
+*   @file     cn0357.cpp
+*   @brief    Source file for CN0357
+*   @author   Analog Devices Inc.
+*
+* For support please go to:
+* Github: https://github.com/analogdevicesinc/mbed-adi
+* Support: https://ez.analog.com/community/linux-device-drivers/microcontroller-no-os-drivers
+* Product: www.analog.com/EVAL-CN0357-ARDZ
+* More: https://wiki.analog.com/resources/tools-software/mbed-drivers-all
+
+********************************************************************************
+* Copyright 2016(c) Analog Devices, Inc.
+*
+* All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions are met:
+*  - Redistributions of source code must retain the above copyright
+*    notice, this list of conditions and the following disclaimer.
+*  - Redistributions in binary form must reproduce the above copyright
+*    notice, this list of conditions and the following disclaimer in
+*    the documentation and/or other materials provided with the
+*    distribution.
+*  - Neither the name of Analog Devices, Inc. nor the names of its
+*    contributors may be used to endorse or promote products derived
+*    from this software without specific prior written permission.
+*  - The use of this software may or may not infringe the patent rights
+*    of one or more patent holders.  This license does not release you
+*    from the requirement that you obtain separate licenses from these
+*    patent holders to use this software.
+*  - Use of the software either in source or binary form, must be run
+*    on or directly connected to an Analog Devices Inc. component.
+*
+* THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
+* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
+* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+* IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+* LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
+* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+********************************************************************************/
+
+#include "mbed.h"
+#include "AD7790.h"
+#include "AD5270.h"
+#include "CN0357.h"
+
+/**
+ * @brief CN0357 constructor
+ * @param CSAD7790 - (optional)chip select of the AD7790
+ * @param CSAD5270 - (optional)chip select of the AD5270
+ * @param MOSI - (optional)pin of the SPI interface
+ * @param MISO - (optional)pin of the SPI interface
+ * @param SCK  - (optional)pin of the SPI interface
+ */
+CN0357::CN0357(PinName CSAD7790, PinName CSAD5270, PinName MOSI, PinName MISO,
+               PinName SCK) :
+    _vref(1.2), _sensor_sensitivity(0), _sensor_range(0), _RDACvalue(0),
+    ad7790(_vref, CSAD7790, MOSI, MISO, SCK), ad5270(CSAD5270, 20000.0, MOSI, MISO, SCK)
+
+{
+}
+
+/**
+ * @brief initializes the AD7790 and the AD5270
+ * @param range - range of the sensor used (in ppm)
+ * @param sensitivity - sensitivity of the sensor (A/ppm)
+ * @param jp - (optional)jumper configuration of the CN0357
+ * @param mode_val - (optional)if jp is set to InternalADC, configures the mode register of the Internal ADC
+ * @param filter_val - (optional)if jp is set to InternalADC, configures the filter register of the Internal ADC
+ */
+void CN0357::init(float range, float sensitivity, JumperConfig_t jp, uint8_t mode_val, uint8_t filter_val)
+{
+    ad5270.frequency(500000);
+    ad7790.frequency(500000);
+
+    float resistance = set_sensor_parameters(range, sensitivity);
+
+    if(jp == INTERNAL_AD7790) {
+        _AD7790_init(mode_val, filter_val);
+    }
+    _rdac_init(resistance);
+}
+
+/**
+ * @brief initializes the RDAC and sets SDO to HiZ
+ * @param resistance - resistance value to initialize the RDAC
+ * @return
+ */
+void CN0357::_rdac_init(float resistance)
+{
+    /* RDAC initialization*/
+    /* Compute for the nearest RDAC value from given resistance and save data to the structure */
+    set_RDAC_value(resistance);
+    /* Set AD5270 SDO to Hi-Z */
+    ad5270.set_SDO_HiZ();
+}
+
+/**
+ * @brief initializes the AD7790
+ * @param mode_val -  configures the mode register of the Internal ADC
+ * @param filter_val -  configures the filter register of the Internal ADC
+ */
+void CN0357::_AD7790_init(uint8_t mode_val, uint8_t filter_val)
+{
+    ad7790.reset();
+    wait_ms(50);
+
+    ad7790.write_mode_reg(mode_val);
+    wait_us(2);
+
+    ad7790.write_filter_reg(filter_val);
+    wait_ms(50);
+}
+
+/**
+ * @brief reads the status register of the AD7790
+ * @return status register value
+ */
+uint8_t CN0357::read_adc_status(void)
+{
+    return ad7790.read_status_reg();
+}
+
+/**
+ * @brief reads the ADC and computes the sensor voltage
+ * @return sensor voltage
+ */
+float CN0357::read_sensor_voltage(void)
+{
+    return ad7790.read_voltage();
+}
+
+/**
+ * @brief reads the data register of the AD7790
+ * @return data register value
+ */
+uint16_t CN0357::read_sensor(void)
+{
+    return ad7790.read_u16();
+}
+
+/**
+ * @brief reads and computes the sensor reading in PPM
+ * @return value of the sensor reading in PPM
+ */
+float CN0357::read_ppm()
+{
+    return calc_ppm(ad7790.read_voltage()); /* Convert voltage to Gas concentration*/
+}
+
+/**
+ * @brief computes a value in PPM from a reading received as a param
+ * @param adcVoltage - voltage to be converted to PPM
+ * @return sensor value in PPM
+ */
+float CN0357::calc_ppm(float adcVoltage)
+{
+    float fConcentration = 0;
+    fConcentration = (fabs(adcVoltage) / _RDACvalue) / _sensor_sensitivity;
+    return fConcentration;
+}
+
+/**
+ * @brief computes voltage from a 16 bit ADC value received as a parameter
+ * @param data - ADC value
+ * @return sensor voltage
+ */
+float CN0357::data_to_voltage(uint16_t data)
+{
+    return ad7790.data_to_voltage(data);
+}
+
+/**
+ * @brief sets a new value for the RDAC
+ * @param resistance new value for the resistance
+ * @return none
+ */
+void CN0357::set_RDAC_value(float resistance)
+{
+    _RDACvalue = ad5270.write_RDAC(resistance);
+}
+
+/**
+ * @brief getter method for RDAC value
+ * @return value of the RDAC in ohms
+ */
+float CN0357::get_RDAC_value()
+{
+    return _RDACvalue;
+}
+
+/**
+ * @brief set sensor range and sensitivity
+ * sets sensor range, sensitivity
+ * returns suggested resistance value for feedback resistor
+ * @param range - range of the sensor used (in ppm)
+ * @param sensitivity - sensitivity of the sensor (in A/ppm)
+ * @return suggested resistance value for feedback resistor
+ */
+float CN0357::set_sensor_parameters(float range, float sensitivity)
+{
+    _sensor_sensitivity = static_cast<float>(sensitivity);
+    _sensor_range = range;
+    return (_vref / (static_cast<float>(_sensor_range * _sensor_sensitivity)));
+}
+
+/**
+ * @brief getter method for sensor sensitivity
+ * @return sensor sensitivity (in A/ppm)
+ */
+float CN0357::get_sensor_sensitivity()
+{
+    return _sensor_sensitivity;
+}
+
+/**
+ * @brief getter method for sensor range
+ * @return sensor range (in ppm)
+ */
+float CN0357::get_sensor_range()
+{
+    return _sensor_range;
+}