[McHUG] Serial for debugging Arduino code

[Rich Mitchell]

McHUGgers,
I have been trying to convert Pete's Si570 code into an Arduino sketch using the Wire library (TWI, I2C), so far without much success.  But along the way I have discovered a good way to debug.  Use Serial that's already part of Arduino, no library to include, initialize Serial in setup() and write out statements and variables to your Serial console from the loop().  If you are already using your serial cable and P4 to upload code to the Arduino, there is no additional hardware setup.  All you have to do is turn on Arduino's serial monitor (once you have uploaded the sketch) and watch the statements come back.  I'm copyiing in the sketch for Blink and adding Serial debugging statements that tell you if the led should be on or off.  This should work okay, but I haven't got back to my Arduino environment to test it.

/* Blinking LED
 * ------------
 *
 * turns on and off a light emitting diode(LED) connected to a digital  
 * pin, in intervals of 2 seconds. Ideally we use pin 13 on the Arduino 
 * board because it has a resistor attached to it, needing only an LED
 *
 * Created 1 June 2005
 * copyleft 2005 DojoDave <http://www.0j0.org>
 * http://arduino.berlios.de
 *
 * based on an orginal by H. Barragan for the Wiring i/o board
 */
int ledPin = 13;                 // LED connected to digital pin 13
void setup()
{
  pinMode(ledPin, OUTPUT);      // sets the digital pin as output
  Serial.begin(9600);           // initialize Serial to 9600 baud.
}
void loop()
{
  digitalWrite(ledPin, HIGH);   // sets the LED on
  Serial.print("Pin ");         // send a string using print
  Serial.print(ledPin);         // send a variable using print
  Serial.println(" is on."); // send string and CRLF with println
  delay(1000);                  // waits for a second
  digitalWrite(ledPin, LOW);    // sets the LED off
  Serial.print("Pin ");         // send a string using print
  Serial.print(ledPin);         // send a variable using print
  Serial.println(" is off."); // send string and CRLF with println
  delay(1000);                  // waits for a second
}


I've been using Serial.println() to see how far I'm getting in the Si570 sketch - which compiles fine.  When it tries to read reg 137, it just hangs.  The Si570 chip starts a tone at 7.075 MHz which may be a default.  Anyway, the Serial class is a big help in debugging.

Rich, N3III
--
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