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Wire

write()

Description

Writes data from a slave device in response to a request from a master, or queues bytes for transmission from a master to slave device (in-between calls to beginTransmission() and endTransmission()).

Syntax

Wire.write(value)
Wire.write(string)
Wire.write(data, length)

Parameters

value: a value to send as a single byte

string: a string to send as a series of bytes

data: an array of data to send as bytes

length: the number of bytes to transmit

Returns

byte: write() will return the number of bytes written, though reading that number is optional

Example

#include <Wire.h> byte val = 0 ; void setup ( )
{
  Wire.begin ( ) ; // join i2c bus
} void loop ( )
{
  Wire.beginTransmission ( 44 ) ; // transmit to device #44 (0x2c)
                              // device address is specified in datasheet
  Wire.write (val) ;             // sends value byte  
  Wire.endTransmission ( ) ;     // stop transmitting   val++;        // increment value
  if (val == 64 ) // if reached 64th position (max)
  {
    val = 0 ;    // start over from lowest value
  }
  delay ( 500 ) ;
}