Arduino and cRIO serial connection

Technical Programming
1

I’ve been working on using an arduino to control lights and maybe read sensors on our robot. I have decided to try to use serial instead of SPI or I2C because there isn’t much documentation about the Arduino being the slave for either of them. I believe that the cRIO’s serial port uses full voltage RS-232 serial and the arduino uses 5v TTL. I have found an old MAX232 based level converter board that I have laying around and I think that the cRIO will work with it. I know how to connect the Tx and Rx of the cRIO and Arduino, but I don’t know if or what I have to do with the other pins. Do I only need ground, tx, and rx, or do I need to connect the others?

2

I wouldn’t abandon the I2C interface yet.
http://wiring.org.co/learning/libraries/ has some examples of how to use the arduino as a slave in an I2C system. Look under “slave sender.”

3

Wow, I had no idea that the arduino could be a slave. I was using an older version of the wire library that did not have good documentation. I would like to use i2c, but I have no idea how to send more than one byte between the two devices. Do you know where I could find an example for sending an integer or a string? I can only seem to find information about sending one byte.

4

On this page look at the master slave examples for the wire lib.
http://arduino.cc/en/Tutorial/HomePage

5

Thanks for the quick reply! I understand how it works, but I am unsure how I would go about storing the transmitting information to a variable. From what I understand, it sends one character at a time. Then, for the last one, it will send the end of the line. I think that if I wanted to store the string, I would have to add all of the letters together, then stop when I got the new line. For what I am trying to do, I would like to send several integers. If I sent three integers separated by commas (12,45,65), could I read it using


void receiveEvent(int howMany)
{
  while(Wire.available()) 
  {
 int a = Wire.parseint(); 
 int b = Wire.parseint(); 
 int c = Wire.parseint(); 

         
  }
  
}