am2315: Sensor added

Signed-off-by: William Penner <william.penner@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/am2315/am2315.h

@@ -0,0 +1,195 @@
+/*
+ * Author: William Penner <william.penner@intel.com>
+ * Copyright (c) 2014 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <string>
+#include <mraa/i2c.h>
+#include <math.h>
+
+#define AM2315_NAME "am2315"
+#define AM2315_I2C_ADDRESS 0x5c
+
+#define AM2315_READ     0x03
+#define AM2315_WRITE    0x10
+
+/* AM2315 Commands */
+#define AM2315_HUMIDITY 0x00
+#define AM2315_TEMP     0x02
+#define AM2315_MODEL    0x08
+#define AM2315_VERSION  0x0A
+#define AM2315_ID       0x0B
+#define AM2315_STATUS   0x0F
+#define AM2315_USER_A   0x10
+#define AM2315_USER_B   0x12
+
+#define AM2315_SAMPLE   2
+
+namespace upm {
+
+/**
+ * @brief AM2315 humidity sensor library
+ * @defgroup htu21d libupm-htu21
+ */
+
+/**
+ * @brief C++ API for AM2315 chip (Atmospheric Pressure Sensor)
+ *
+ * Measurement Specialties [AM2315]
+ * (http://www.aosong.com/asp_bin/Products/en/AM2315.pdf)
+ * is a digital humidity sensor with temperature output.
+ * RH will report between 0 and 100% and temperature range is
+ * -40 to +125 degC.
+ * The sampling period of this sensor is 2 seconds.  Reads occurring
+ * more often than that will return cached data.
+ *
+ * @ingroup am2315 i2c
+ * @snippet am2315.cxx Interesting
+ * @image html am2315.jpeg
+ */
+class AM2315 {
+    public:
+        /**
+         * Instanciates a AM2315 object
+         *
+         * @param bus number of used bus
+         * @param devAddr address of used i2c device
+         * @param mode AM2315 oversampling
+         */
+        AM2315 (int bus, int devAddr=AM2315_I2C_ADDRESS);
+
+        /**
+         * AM2315 object destructor, basicaly it close i2c connection.
+         */
+        ~AM2315 ();
+
+        /**
+         * Get the current measured humidity [RH]
+         * Data is updated every 2 seconds - accesses more often than
+         * that will return cached data
+         */
+        float getHumidity(void);
+
+        /**
+         * Get the humidity cell temperature [degC]
+         * Data is updated every 2 seconds - accesses more often than
+         * that will return cached data
+         */
+        float getTemperature(void);
+
+        /**
+         * Get the humidity cell temperature [degF]
+         * Data is updated every 2 seconds - accesses more often than
+         * that will return cached data
+         */
+        float getTemperatureF(void);
+
+        /**
+         * Function intended to test the device and verify it
+         * is correctly operating.
+         *
+         */
+        int testSensor(void);
+
+        /**
+         * Write four byte (32b) register
+         *
+         * Note: These access routines are not the normal accesses to an i2c
+         * device.  The AM2315 contains a microcontroller that manages the
+         * actual readings.  These handlers then make requests over i2c using
+         * a protocol defined by the AM2315.
+         *
+         * @param reg address of a register
+         * @param ival 32b value
+         */
+        int i2cWriteReg_32(int reg, uint32_t ival);
+
+        /**
+         * Write two byte (16b) register
+         *
+         * @param reg address of a register
+         * @param ival 16b value
+         */
+        int i2cWriteReg_16(int reg, uint16_t ival);
+
+        /**
+         * Write one byte (8b) register
+         *
+         * @param reg address of a register
+         * @param ival 8b value
+         */
+        int i2cWriteReg_8(int reg, uint8_t ival);
+
+        /**
+         * Read four bytes register
+         *
+         * @param reg address of a register
+         */
+        uint32_t i2cReadReg_32 (int reg);
+
+        /**
+         * Read two bytes register
+         *
+         * @param reg address of a register
+         */
+        uint16_t i2cReadReg_16 (int reg);
+
+        /**
+         * Read one byte register
+         *
+         * @param reg address of a register
+         */
+        uint8_t i2cReadReg_8 (int reg);
+
+    private:
+
+        char* m_name;
+
+        int m_controlAddr;
+        int m_bus;
+        mraa_i2c_context m_i2ControlCtx;
+
+        void update_values(void);
+        uint8_t i2cReadReg(int reg, uint8_t* data, int ilen);
+        int i2cWriteReg(uint8_t reg, uint8_t* data, uint8_t ilen);
+        uint16_t crc16(uint8_t* ptr, uint8_t len);
+        void initialize_priority(void);
+        void high_priority(void);
+        void normal_priority(void);
+
+        int32_t   m_temperature;
+        int32_t   m_humidity;
+
+        uint16_t  m_model;
+        uint16_t  m_version;
+        uint32_t  m_id;
+
+        time_t    m_last_time;
+
+        bool      m_use_priority;
+        struct    sched_param base_params;
+        int       base_policy;
+        pthread_t this_thread;
+};
+
+}