ok, I'm tired, I spent all day trying to get rid of this strange issue.
Let's take a look...
1) This is the code:
int val = 0;
Wire.begin(); // join i2c bus
Wire.beginTransmission(0x00); // transmit to device #
Wire.write(0xc1); //default init command 0xc1
Wire.write(0xd1); //sub call address select 0xd1
Wire.write(0x00); //registro initialization call 0x00
Wire.write(0x01); //registro setup 0x01
Wire.write(0x14); //primo gruppo led0 init 0x14
Wire.write(0x55); //(01010101 -> 01 led full on 0x55
Wire.endTransmission(); // stop transmitting
val++; // increment value
if(val == 64) // if reached 64th position (max)
val = 0; // start over from lowest value
2) this is are results from the logic analyzer:
The link of the pictures, in case will not work due to access of flickr:http://farm6.staticflickr.com/5508/9110418244_532144983e_b.jpghttp://farm4.staticflickr.com/3680/9108260063_7071e9a93f_b.jpg
3) Additional info:
Operating systems used to test the sw ubuntu 64bit & win7 64bit.
Latest version of beta 1.5.2 for DUE.
It seems that instead to sending the content of the Wire.write funcion it sends again and again the Wire.beginTransmission value.
If I change the beginTransmission value I simply get the new value repeated again and again for the total number of the Wire.write typed in the code.
I don't have enough knowledge to modify the library or... am I doing something wrong?
Thanks a million for your help!