Arduino Primo I2C bus problem

RE: Arduino Primo I2C bus problem

MartinBL — Tue, 17 Oct 2017 11:34:29 GMT

Did you try to queue a byte with Write.write() after Wire.beginTransmission, as suggested in my link?

RE: Arduino Primo I2C bus problem

Gaetano Criscuolo — Tue, 17 Oct 2017 10:03:14 GMT

No, I do not have a logical analyzer. How can I do? I have two Arduino Primo and behave the same way.

RE: Arduino Primo I2C bus problem

MartinBL — Tue, 17 Oct 2017 10:00:00 GMT

Do you have a logic analyzer so you can see if the Primo transfers anything at all? It seems like beginTransmission() doesn't actually transmit anything and that endTransmission() is happy with that and returns 0 every time.

RE: Arduino Primo I2C bus problem

Gaetano Criscuolo — Tue, 17 Oct 2017 08:31:33 GMT

Hi Martin, yes, this is code.

#include <Wire.h>

void setup() {
  Serial.begin (9600);

  // Leonardo: wait for serial port to connect
  while (!Serial)
  {
  }

  Serial.println ();
  Serial.println ("I2C scanner. Scanning ...");
  byte count = 0;

  Wire.begin();
  for (byte i = 8; i < 120; i++)
  {
    if (i != 72) // Questo indirizzo blocca Arduino Primo
    {
      Wire.beginTransmission (i);
      if (Wire.endTransmission () == 0)
      {
        Serial.print ("Found address: ");
        Serial.print (i, DEC);
        Serial.print (" (0x");
        Serial.print (i, HEX);
        Serial.println (")");
        count++;
        delay (1);  // maybe unneeded?
      } // end of good response
    }
    else
    {
      Serial.print ("Skip address: ");
      Serial.print (i, DEC);
      Serial.print (" (0x");
      Serial.print (i, HEX);
      Serial.println (")");
    }
  } // end of for loop
  Serial.println ("Done.");
  Serial.print ("Found ");
  Serial.print (count, DEC);
  Serial.println (" device(s).");
}  // end of setup

void loop() {}

RE: Arduino Primo I2C bus problem

MartinBL — Tue, 17 Oct 2017 08:29:08 GMT

That's pretty strange. Can you point me to the code you are using for this?