Ok. Thanks! So, when you switch the power jumper over to USB, then it expects a 5V regulated supply coming in, correct?

I just bought an Arduino Diecimila, which is pretty easy to figure out except one thing. There is a pin (near the "POWER" section on the dev. board) in between "RESET" and "5V" that says "3V3". What is that for? I would like to think it's a 3V regulated supply; that would be awesome for certain non-5V add-ons! Am I right, or just dreaming?

Hmmm....It's still not returning proper values. did you mean that the constant was supposed to be just "813" or "$813"? I tried both, and the debug window on the BS2 program is still giving me improper values. I know I have everything else right; the Arduino is set for 1200bps, all the connections are right...I also tried the carriage return on both the BS2e ("DEBUG CR, ...) AND the Arduino (Serial.Println ...). What could be wrong?  

First off, I am not sure about support in these forums for BASIC Stamps, but I need to interface one to the Arduino. I am having trouble, though. I am trying to get the Arduino to read an analog value, convert it to digital, then send the result over a serial line to the BS2e (Basic Stamp 2e). The BS2e then stores the result in a variable, and displays it in a debug terminal (aka "serial monitor" according to the Arduino software). Here's the Arduino code:

Code:

//int txPin = 7;
int micPin = 0;
int val = 0;

void setup() {
      Serial.begin(1200);      // opens serial port, sets data rate to 9600 bps
        //pinMode(Tx_pin, OUTPUT);
}

void loop()
{
  val = analogRead(micPin);
  Serial.print(val);
  //digitalWrite(txPin, val);
  delay(200);
}

Ignore the commented out parts (with the "//").

...And here's the PBASIC code (again, ignore the commented out stuff with a " ' ")

Code:

' {$STAMP BS2e}
' {$PBASIC 2.5}

value           VAR     Word(3)

'Tx              PIN     0
Rx              PIN     1
Baud            CON     1200

DO

  'value = 0
  SERIN Rx, Baud, [value]
  'IF value > 0 THEN
    DEBUG HOME, DEC value
  'ENDIF

LOOP

Maybe someone has experience with BASIC...? Thanks!

Cool. Thanks; that worked! I figured that might work. I used a 1.5m resistor across the smaller cap.

For a while now, I have been trying to find an easy solution for a robotic 'ear'. I used to use the BASIC Stamp a lot, but now that I am learning the Arduino, I finally have an easier way to do this: A/D! I was asking around in their forums (http://forums.parallax.com/forums/default.aspx?f=5&m=225985&g=226129#m226129), and came up with an easy circuit (http://forums.parallax.com/forums/attach.aspx?a=5154). When I connect it to the Arduino, all I have to do is use the leads that are supposed to go to the LED in the schematic, connecting + to an analog pin, and - to GND. The problem is, when it hears a really loud sound, it takes a really long time even after the sound is gone for the value from the A/D converter to settle down again. And the odd thing is, when I test this with an LED, the LED does NOT stay lit and slowly dim from the input just as the value from the Arduino A/D shows. What's going on? I tried using different value resistors connected to the output of the audio circuit, but that didn't help. Does it have to do with the caps? Or with the Arduino itself...?