Diff: tca9554a.h

Revision:

1:e02d9e33b9f3

Parent:

0:402147fa55f6

--- a/tca9554a.h	Wed May 04 00:40:25 2016 +0000
+++ b/tca9554a.h	Thu May 05 17:55:38 2016 +0000
@@ -3,6 +3,51 @@
 
 #include "mbed.h"
 
+/**
+ * Device driver for TCA9554A.
+ * @note TCA9554A is a GPIO expander with I2C interface.
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "tca9554a.h"
+ *
+ * #define I2C_SPEED_100KHZ    100000
+ * #define I2C_SPEED_400KHZ    400000
+ * 
+ * int main(void) {
+ *     // Instanciate I2C
+ *     I2C i2c(I2C_SDA0, I2C_SCL0);
+ *     i2c.frequency(I2C_SPEED_400KHZ);
+ *
+ *     // Instanciate TCA9554A
+ *     // Suppose that the slave address of TCA9554A on your board is 38H.
+ *     TCA9554A tca9554a(&i2c, TCA9554A::SLAVE_ADDRESS_38H);
+ *     
+ *     // Configure the GPIO ports. 
+ *     // Default direction of the ports are input and polarity inversion is disabled.
+ *     // Here, sets port 3 to output and port 5 to input with polarity inversion.
+ *     if (tca9554a.configurePort(TCA9554A::PORT_3, TCA9554A::DIR_OUTPUT)!= TCA9554A::SUCCESS) {
+ *         // @TODO: error handling
+ *     }
+ *     if (tca9554a.configurePort(TCA9554A::PORT_5, TCA9554A::DIR_INPUT, TCA9554A::INVERTING) != TCA9554A::SUCCESS) {
+ *         // @TODO: error handling
+ *     }
+ * 
+ *     while(true) {
+ *         LogicLevel val = TCA9554A::LOW;
+ *         // Reads the value from port 5 and sets the read value to port 3.
+ *         // Note that the read value is inverted from the actual input level, 
+ *         // because the port 5 is configured as INVERTING at the initialization process above.
+ *         if (tca9554a.getPortLevel(&val, TCA9554A::PORT_5) != SUCCESS) {
+ *             // @TODO: error handling
+ *         }
+ *         if (tca9554a.setPortLevel(TCA9554A::PORT_3, val) != SUCCESS) {
+ *             // @TODO: error handling
+ *         }
+ *     }
+ * }
+ * @endcode
+ */
 class TCA9554A 
 {
 public:
@@ -21,7 +66,7 @@
     } SlaveAddress;
 
     /**
-     * Status of function. 
+     * Result status of function execution. 
      */
     typedef enum {
         SUCCESS,               /**< The function processed successfully. */
@@ -31,7 +76,7 @@
     } Status;
 
     /**
-     * Port number.
+     * GPIO port number.
      */
     typedef enum {
         PORT_0 = 0x01,         /**< Port 0. */
@@ -48,28 +93,30 @@
      * Port value.
      */
     typedef enum {
-        LOW = 0,
-        HIGH = 1,
+        LOW = 0,              /**< Indicates low level. */
+        HIGH = 1,             /**< Indicates high level. */
     } LogicLevel;
     
     /**
      * Direction of a port.
      */    
     typedef enum {
-        DIR_OUTPUT = 0x00,
-        DIR_INPUT = 0x01,
+        DIR_OUTPUT = 0x00,    /**< Output. */
+        DIR_INPUT = 0x01,     /**< Input. */
     } Direction;
 
     /**
      * Flag for enabling input polarity inversion.
      */
     typedef enum {
-        NON_INVERTING = 0x00,
-        INVERTING = 0x01,
+        NON_INVERTING = 0x00,  /**< Input polarity is not inverted. */
+        INVERTING = 0x01,      /**< Input polarity is inverted. */
     } PolarityInversion;
 
     /**
      * Constructor. In default, all the ports are set as input.
+     * @param conn Pointer to an instance of I2C.
+     * @param addr Slave address of this device.
      */
     TCA9554A(I2C *conn, SlaveAddress addr);