stamp.peripheral.io
Class I2C

java.lang.Object
  |
  +--stamp.peripheral.io.I2C

public class I2C

extends Object

This class defines a physical bus and provides essential I2C protocol routines. The bus pins should be pulled up to Vdd through 4.7K resistors.

This class can be used as-is, but will usually be referenced by a specific device class that uses the I2C bus. Direct use of this class requires the programmer to have some understanding of the I2C bus and protocol. Consult Philips documentation for details:

http://www.semiconductors.philips.com/i2c/

Creating the bus requires two available pins: SDA (serial data) and SCL (serial clock).

I2C ioBus = new I2C(CPU.pin0, CPU.pin1); // SDA on pin 0; SCL on pin 1

Field Summary

static int	ACK
static int	NAK
protected int	sclPin
protected int	sdaPin

Constructor Summary

I2C(int sdaPin, int sclPin)
Creates I2C bus object and intializes bus pins.

Method Summary

int	read(int ackBit) Read 8-bit value from I2C device.
void	start() Send I2C Start sequence.
void	stop() Send I2C Stop sequence.
boolean	write(int i2cData) Write 8-bit value to I2C device.

Methods inherited from class java.lang.Object

equals

Field Detail

ACK

public static final int ACK

NAK

public static final int NAK

sdaPin

protected int sdaPin

sclPin

protected int sclPin

Constructor Detail

I2C

public I2C(int sdaPin,
           int sclPin)

Creates I2C bus object and intializes bus pins.

Parameters:

sdaPin - I2C serial data pin (bi-directional)

sclPin - I2C serial clock pin

Method Detail

start

public void start()

Send I2C Start sequence.

write

public boolean write(int i2cData)

Write 8-bit value to I2C device.

Parameters:

i2cData - Value to write to I2C device

Returns:

True if device returned Ack; False if Nak

read

public int read(int ackBit)

Read 8-bit value from I2C device.

Parameters:

ackBit - 0 to send Ack; 1 to send Nak after receipt of data

Returns:

Value from I2C device

stop

public void stop()

Send I2C Stop sequence.