using Xoscope or Arduinoscope to probe analog circuits

Using Arduino Interfacing w/ Software on the Computer
1

Hello all, I have a two part question. I need to test the responsiveness of some piezo sensors, and came across Xoscope [for ubuntu] an oscilloscope that uses a sound card (via /dev/dsp or EsounD) as the signal input. The Built-in mic on my laptop delivers an audio level reading to the scope. So far so good. Question:

  1. "Buffer Hardware for xoscope"
    Is it safe to use the mini inputs jacks on my laptop to probe an analog circuit with or without the buffer Hardware. See Xoscope here: http://xoscope.sourceforge.net/ NOTE: Buffer Hardware for xoscope Buffer Hardware for xoscope

This post frames it nicely. xoscope: digital oscilloscope / Discussion / Help: Hardware : 150V protection

How much voltage can I have at the RCA jack before my soundcard fries.

(I have read somewhere that the maximum inline of a soundcard is about 2 V, is this true)

and
2. "Processing and Mega 2560"
I trying to use arduinoscope with the Arduino Mega 2560.
Processing reports:
ArrayIndexOutOfBoundsException: 0
port = new Serial(this, Serial.list()[0], 115200); I don't get this with the ArduinoDuemilanove. Unfortunately I need it to run using the Mega 2560 as that's my spare at the moment.
See Arduinoscope here: Google Code Archive - Long-term storage for Google Code Project Hosting.

Any Ideas?
Thanks much!

2

I don't get this with the ArduinoDuemilanove. Unfortunately I need it to run using the Mega 2560 as that's my spare at the moment.

Are you able to upload sketches to the Mega? Processing is telling you that it can't see the Mega, which implies that the drivers are missing.

Is this on ubuntu?

3

Is this on ubuntu?

corect.
Processing-1.5.1
Yes, I am able to upload arduinoscope.pde to the Mega.

I've confirmed that Processing does not talk to the Mega 2560.

4

I installed the Processing library for arduinoMega: processing-arduinomega.zip from Arduino Playground - HomePage but the result is the same.

ArrayIndexOutOfBoundsException: 0

port = new Serial(this, Serial.list()[0], 115200);