Package com.oracle.deviceaccess.i2cbus

Interfaces and classes for I2C (Inter-Integrated Circuit Bus) device access.

See: Description

Interface Summary

Interface	Description
I2CDevice	The I2CDevice interface provides methods for sending and receiving data to/from an I2C slave device.

Class Summary

Class	Description
I2CCombinedMessage	The I2CCombinedMessage class allows for constructing a combined message.
I2CDeviceConfig	The I2CDeviceConfig class encapsulates the hardware addressing information, and static and dynamic configuration parameters of an I2C slave device.
I2CPermission	The I2CPermission class defines permissions for I2C slave device access.

Package com.oracle.deviceaccess.i2cbus Description

Interfaces and classes for I2C (Inter-Integrated Circuit Bus) device access.

The functionalities supported by this API are those of an I2C master.

In order to communicate with a specific slave device, an application should first open and obtain an I2CDevice instance for the I2C slave device the application wants to exchange data with, using its numerical ID, name, type (interface) and/or properties:

Using its ID

 I2CDevice slave = (I2CDevice) PeripheralManager.open(3);
 

Using its name and interface

 I2CDevice slave = PeripheralManager.open("ADC1", I2CDevice.class, null);
 

Once the peripheral opened, the application can exchange data with the I2C slave device using methods of the I2CDevice interface such as the write() method.

 slave.write(sndBuf, 0, 1);
 

When the data exchange is over, the application should call the Peripheral.close() method to close the I2C slave device.

 slave.close();
 

The following samples code give 2 examples of using the I2C API to communicate with an I2C slave device:

 try (I2CDevice slave = PeripheralManager.open("LED_CONTROLLER", I2CDevice.class, null)) {
     ByteBuffer stopCmd = ByteBuffer.wrap(LED_STOP_COMMAND);
     ByteBuffer offCmd = ByteBuffer.wrap(LED_OFF_COMMAND);
     ByteBuffer onCmd = ByteBuffer.wrap(LED_ON_COMMAND);
     // Clear all status of the 'LED' slave device
     slave.write(ByteBuffer.wrap(stopCmd));
     slave.write(ByteBuffer.wrap(offCmd));
 
     for (int i = 0; i < LED_LOOP_COUNT; i++) {
         // turning 'LED' on and keeping it on for 1500ms
         slave.write(ByteBuffer.wrap(onCmd));
         try {
             Thread.sleep(LED_BLINK_TIME);
         } catch (InterruptedException ex) {
         }
 
         // turning 'LED' off keeping it off for 1500ms
         slave.write(ByteBuffer.wrap(offCmd));
         try {
             Thread.sleep(LED_BLINK_TIME);
         } catch (InterruptedException ex) {
         }
     }
 } catch (IOException ioe) {
     // handle exception
 }
 

Or,

 try (I2CDevice slave = PeripheralManager.open("EEPROM", I2CDevice.class, (String) null)) {
     try {
         byte[] addr = new byte[]{/*Somme address* /};
         ByteBuffer data = ByteBuffer.allocateDirect(4);
         slave.begin();
         slave.write(ByteBuffer.wrap(addr)); // Writes the address
         int count = slave.read(data); // Read the data at that EEPROM address
     } finally {
         slave.end();
     }
 }
 

Note that the preceding examples are using a try-with-resources statement and that the I2CDevice.close() method is automatically invoked by the platform at the end of the statement.

Information about the I2C-bus specification can be found at http://www.nxp.com/documents/user_manual/UM10204.pdf.

Unless otherwise noted, passing a null argument to a constructor or method in any class or interface in this package will cause a NullPointerException to be thrown.