Wire.beginTransmission(deviceaddress);
Wire.write((int)(eeaddress >> 8)); // MSB
Wire.write((int)(eeaddress & 0xFF)); // LSB
Wire.write((int)(data >> 8)); // MSB
Wire.write((int)(data & 0xFF));
Wire.endTransmission();
}

void setup(void)
{
unsigned int address = 0;
Serial.begin(9600);
Wire.begin();

}

void loop(){

unsigned int address = 0;
if (Serial.available()) {
integerValue = 0;
while(1) {
incomingByte = Serial.read(); // char
if (incomingByte == ‘\ ‘) break;
if (incomingByte == -1) continue;
integerValue *= 10; // shift left 1 decimal place
// convert ASCII to integer, add, and shift left 1 decimal place
integerValue = ((incomingByte – 48) + integerValue);
}
}
Serial.println(integerValue); // Do something with the value
delay(500);
writeEEPROM(disk1, address, integerValue);

}

OUTPUT: DIGITAL VAL=4000, MY VOLT =4.8V THE I2C IS WORKING FOLLOWING MANOR: S C0 A 00 A 00 A F0 A 11 A P

THIS CODE IS USED TO DAC. THIS WORKING PREFECT IN ONE TIME. that means the data write once in dac the dac provide equal volt. and next time arduino send stop bit the communication stopped here.MY AIM THE DIGITAL VALUE IS PROVIDE BY USING SERIAL SO I NEED WRITE DATA CONTINUES PLEASE ANY ONE HELP ME.
I WILL TRY ANOTHER METHOD for repeated start BY REPLACING THE LINE IN ABOVE CODE, THIS SEND DATA CONTINUES BUT IN THE DAC do not produce OUTPUT VOLTAGE. THIS MY PROBLEM.
THE CHANGES IS :Wire.endTransmission(false);
the output is:S SR C0 A 00 A 00 A F0 A 11 A SR C0 A 00 A 00 A F0 A 11 A ……. TO FOLLOW THIS MANOR. PLEASE any one HELP ME AM WAIT U R REPLY THANK YOU

And about the unique DS1620 it is indeed like that. I recall using one with the BASIC Stamp.

The DS620 doesn’t use the I2C standard of course. It uses something completely different. Naturally the website does describe how the protocol methods and the ways to make it work.

By way of example:

#define mult(X,Y) X * Y
...
a = mult(b+5, c+3);

expands into

a = b+5 * c+3;

which is (with a change in whitespace to show order of operations)

a = b + 5*c + 3;

which is unlikely to be what was intended. So I always parenthesize macro arguments in #defines.

Further I have implemented a couple of I2C-functions to controll an absolute barometer, an ad-converter and a high side current/power monitor without using the wire-library. My functions use “bit-banging”. This way you have more controll and smaller code. Probably at the expense of speed, but with most I2C-projects speed is not of the utmost importancy.

Thanks in advance, Pim.

i’ve a generall question, i’ve order this device:
http://www.dorji.com/pro/sensor-module/Compass_pressure_sensor.html

and i wonder now if a arduino can handle the command sequence
they put a example program for a pic u-processor online and im not quite sure
if i can handle this with the wire commands

as example – when i understand that minimalistic datasheet right, i’ve to wakup the device and im not quite sure if the timing of the “data read” is possible with the wire library

as example a code snipped how its programmend for the pic u-processor:

unsigned char IIC_ReadByte(void)
{
unsigned char ucValue;
unsigned char ucIndex;
ucValue = 0;
DATA_SET = DATA_INPUT;
SysDelay(DELAY100US);
for ( ucIndex = 0; ucIndex < 8; ucIndex++ )
{
ucValue <<= 1;
IIC_SCL_LOW();
SysDelay(DELAY100US);

IIC_SCL_HIGH();
SysDelay(DELAY100US);
if(DATA)
ucValue |= 1;
SysDelay(DELAY100US);
IIC_SCL_LOW();
SysDelay(DELAY100US);
}
return ucValue;
}

they predefinded #defines are trivial and realy mean mostly 0 or 1

are u used to the wire library and how its programmed so could you tell me if its possible in generall to use this device with arduino and his wire library or do i have to go deeper into that topic and programm my own "wire-library" ?

would be great if you could help me

thx
vance