Diff: INA219.hpp

Revision:

0:eee9c8ba72ff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/INA219.hpp	Thu Aug 28 10:32:20 2014 +0000
@@ -0,0 +1,157 @@
+#include "mbed.h"
+#include "INA219_consts.h"
+
+#define DEBUG
+
+/// Represents the different supported voltage levels
+typedef enum {
+    BUS_16V=16,
+    BUS_32V=32
+} busvoltage_t;
+
+/** @enum Resolution typedef
+ *  @brief Represents the different ADC resolutions supported by the INA219.
+ */
+typedef enum {
+    RES_12BITS=12,  ///< 12 bit precision (532us)
+    RES_11BITS=11,  ///< 11 bit precision (276us)
+    RES_10BITS=10,  ///< 10 bit precision (148us)
+    RES_9BITS =9    ///< 9 bit precision (84us)
+} resolution_t;
+
+/** @class INA219
+ *  @brief A class to represent the INA219 breakout board from Adafruit.
+ */
+class INA219: protected I2C
+{
+public:
+    /** Creates an instance of the INA219 device.
+     *
+     *  @param sda An I2C data pin.
+     *  @param scl An I2C clock pin.
+     *  @param addr The I2C address of the INA219. (Default = 0x40)
+     *  @param freq The I2C clock frequency.
+     *  @param res The desired resolution of the INA219's ADC.
+     */
+    INA219 (PinName sda, PinName scl, int addr=0x40, int freq=100000, resolution_t res=RES_12BITS);
+
+    /** Reads the current raw value of current from the INA219.
+     *
+     *  @see read_current_mA
+     *
+     *  @returns
+     *      A value between -32768 and +32768. Depending on the current calibration and configuration register values, the corresponding current can be calculated.
+     */
+    int16_t read_current_raw();
+    /** Reads the current from the INA219 and calculates the actual value in mA.
+     *
+     *  @see read_current_raw
+     *
+     *  @returns
+     *      A floating point value corresponding to the current flowing through the current shunt, in mA.
+     */
+    float read_current_mA();
+
+    /** Reads the raw power value from the INA219.
+     *
+     *  @see read_power_mW
+     *
+     *  @returns
+     *      A value between -32768 and +32768. Depending on the calibration and configuration register values, the actual power can be calculated.
+     */
+    //int16_t read_power_raw();
+    /** Reads the power from the INA219 and calculates the actual value in mW.
+     *
+     *  @see read_power_raw
+     *
+     *  @returns
+     *      A floating point value corresponding to the power being used in the circuit, in mW.
+     */
+    //float read_power_mW();
+
+    /** Reads the raw shunt voltage value from the INA219.
+     *
+     *  @see read_shunt_voltage_mV
+     *
+     *  @returns
+     *      A value between -32768 and +32768. Depending on the calibration and configuration register values, the actual shunt voltage can be calculated.
+     */
+    //int16_t read_shunt_voltage_raw();
+    /** Reads the shunt voltage from the INA219 and calculates the actual value in mV.
+     *
+     *  @see read_shunt_voltage_raw
+     *
+     *  @returns
+     *      A floating point value corresponding to the potential difference across the current shunt, in mV.
+     */
+    //float read_shunt_voltage_mV();
+
+    /** Reads the raw bus voltage.
+     *
+     *  @see read_bus_voltage
+     *
+     *  @returns
+     *      A value between -32768 and +32768 corresponding to the bus voltage.
+     */
+    //int16_t read_bus_voltage_raw();
+    /** Reads the bus voltage and uses it to calculate the actual bus voltage.
+     *
+     *  @see read_bus_voltage_raw
+     *
+     *  @returns
+     *      A floating point value corresponding to the voltage of V+ (in V).
+     */
+    //float read_bus_voltage();
+
+    /** Sets the calibration register.
+     *     
+     *  Specifies a maximum bus voltage of 16V and maximum current of 400mA.
+     *  
+     */
+    void calibrate_16v_400mA();
+
+protected:
+    resolution_t resolution;
+
+    int i2c_addr;
+    int current_divider;
+    int power_divider;
+    //...
+
+    /** Writes a uint8_t array to the specified I2C register.
+     *
+     *  @see write_register_u16
+     *
+     *  @param reg (8-Bit) Register address to be written to.
+     *  @param data An array of bytes with the data to be written.
+     *  @param length The length of the array.
+     */
+    void write_register(uint8_t reg, uint8_t* data, int length);
+    /** Writes a uint16_t to the specified I2C register.
+     *
+     *  @see write_register
+     *
+     *  @param reg (8-Bit) Register address to be written to.
+     *  @param data (16-Bit) Data to be written.
+     */
+    void write_register_u16(uint8_t reg, uint16_t data);
+    /** Reads a value from the specified I2C register.
+     *
+     *  @see write_register
+     *  @see write_register_u16
+     *
+     *  @param reg (8-Bit) Register to be read from.
+     *
+     *  @returns
+     *      The contents of the specified register, as a 16 bit integer.
+     */
+    uint16_t read_register_u16(uint8_t reg);
+    
+    /** Writes nothing to a specified register. (Used to tell the chip that we want to read from that register)
+     *
+     *  @see read_register_u16
+     *
+     *  @param reg The register for nothing to be written to.
+     */
+     void write_null(uint8_t reg);
+};