Diff: CN0396.h

Revision:

0:ef85449aa57f

Child:

1:024253f170c3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CN0396.h	Mon Nov 07 15:56:24 2016 +0000
@@ -0,0 +1,113 @@
+#ifndef _CN0396_H_
+#define _CN0396_H_
+#include <mbed.h>
+#include "AD7798.h"
+#include "AD5270.h"
+#include "ADT7310.h"
+
+/**
+ * @brief The CN0396 class
+ */
+class CN0396
+{
+public:
+
+#define V_REF                1.200    // [V]
+#define _2_16                65535.0   // 2^16
+#define _2_15                32767.0   // 2^16
+#define COMPENSATION_TABLE_SIZE 9
+
+    typedef enum {
+        CO_SENSOR,
+        H2S_SENSOR
+    } sensor_type_t;
+
+    typedef struct {
+        int8_t temp;
+        float CO_percent;
+        float H2S_percent;
+    } ppm_compensation_t;
+
+	/**
+	 *  @brief compensation look-up table
+	 */
+    const ppm_compensation_t ppm_compensation[COMPENSATION_TABLE_SIZE] = {
+        { -30	, 29.9  , 82.3 },
+        { -20	, 38.8  , 84.6 },
+        { -10	, 53.7  , 88.6 },
+        {0		, 69.6  , 92.2 },
+        {10		, 84.9  , 96.2 },
+        {20		, 100.0 , 100.0},
+        {30		, 112.7 , 103.1},
+        {40		, 123.7 , 105.6},
+        {50		, 133.1 , 107.4}
+    };
+
+
+    /**
+     * @brief CN0396 class constructor
+     * @param csad  - chipselect pin of the ADC
+     * @param csrdac - chipselect pin of the RDAC
+     * @param cstemp - chipselect pin of the temperature sensor
+     */
+    CN0396(PinName csad, PinName csrdac, PinName cstemp);
+    /**
+     * @brief Initializes the board
+     */
+    void init();
+
+    /**
+     * @brief - Reads the sensor and computes the PPM values
+     */
+    void read();
+
+    /**
+     * @brief computes the feedback resistor value for the sensor
+     * @param sensitivity - sensor sensitivity
+     * @param range - sensor range
+     * @return resistor value
+     */
+    float get_feedback_resistor_value(float sensitivity, float range);
+
+    /**
+     * @brief configures the RDACs with the resistance values
+     * @param resistance1 - resistance of RDAC1
+     * @param resistance2 - resistance of RDAC2
+     * @return
+     */
+    void configure_feedback_resistors(float resistance1, float resistance2);
+
+    /**
+    * @brief computes ADC counts-to-voltage in unipolar configuration
+    * @param adcValue - value in counts
+    * @param voltage - voltage value returned by the method
+    * @param gain_adc - the gain of the adc
+    */
+    void data_to_voltage(uint16_t adcValue, float *voltage, int gain_adc = 1);
+
+    /**
+     * @brief computes ADC counts-to-voltage in bipolar configuration
+     * @param adcValue - value in counts
+     * @param voltage - voltage value returned by the method
+     * @param gain_adc - the gain of the adc
+     */
+    void data_to_voltage_bipolar(uint16_t adcValue, float *voltage, int gain_adc = 1);
+
+    /**
+     * @brief compensates ppm value based on temperature reading
+     * @param result - ppm value before compensation
+     * @param temp - temperature used in compensation
+     * @param sensor - sensor id
+     * @return compensated value
+     */
+    float compensate_ppm(float result, float temp, sensor_type_t sensor);
+    DigitalOut csad, csrdac, cstemp;
+    AD7798 ad;
+    AD5270 rdac;
+    ADT7310 temp;
+    float resistance0, resistance1;
+private:
+
+
+};
+#endif