Practical Limits of Serial communications?

Hi Graynomad,

Thanks for the reply. I changed both of them down to 9,600 baud since my FTDI adapter seems to be flaky at 28,800. Might have to to with Win 7 not allowing the driver to be changed easily. So, they're both running at 9,600 baud now. I flipped the FTDI cable back and forth among the two Arduinos, I get clear-text messages on both (i.e. "setup complete", etc.) serial busses, just no communication between the two chips. I have a third RS485 board at home, I'll see if I can eliminate one of the RS485 chips as a possible culprit.

See current Master code below:

/* YourDuino RS485 Master Node S Example
 terry@yourduino.com */

/*-----( Declare Variables )-----*/
int EN = 12;
int LED_PIN =7;

void setup() /****** SETUP: RUNS ONCE ******/
{
  pinMode(EN, OUTPUT );
  pinMode(LED_PIN, OUTPUT );
  Serial.begin (9600);
  Serial1.begin (9600);
  Serial.println ("Setup Complete."); //FTDI Header Send
}//--(end setup )---

void loop()    /****** LOOP: RUNS CONSTANTLY ******/
{
  // Send Data
  digitalWrite(LED_PIN, HIGH ); // turn on light
  digitalWrite(EN, HIGH ); // enable send
  Serial.print ( 'A' ); //FTDI Header Send
  delay (1); //wait for RS485 chip to be active
  Serial1.print ( 'A' ); //RS485 Bus Send

  delay(1000);  
  digitalWrite(LED_PIN, LOW ); // turn off light
  Serial.print ( 'B' );//FTDI Header Send
  Serial1.print ( 'B' ); //RS485 Bus Send
  delay (1000);
}//--(end main loop )---