ProMini FTDI interference traces

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What steps will reproduce the problem?
1. Arduino Pro Mini 3.3v 8MHz with FTDI drivers on any computer (tried on 
3 desktops and two laptops)
2. Use software from here
3. Connect and disconnect a probe wire (tried with 5amp, 8amp and 13amp 
(240v) solid copper wire)

What is the expected output? What do you see instead?
Low voltage readout (when not probing hopefully 0v), with activity only 
when placed upon a signal generating component or part. ~0.3v trace with 
0.8 max (as shown in picture) when only the arduino is connected but when 
a probe wire is connected the max goes straight to 4.8v and the trace 
becomes more irratic. Nothing else is done to the system at all. I have 
even tried connecting 4 probe wires and trying to remove the noise by 
touching other pins on the board.

What version of the product are you using? On what operating system?
Up to date. XP, XP x64, 7, Linux, OSX

Please provide any additional information below.
JPEG supplied has 12 trace graphs (6&6). ProMini is attached to FTDI 
cable, probe cable is attached to ProMini (in this case A0 but same occurs 
at all pins), FTDI cable is then plugged into computer and Processing in 
run. Digital traces have no traces, hopefully because nothing was attached 
and connected.

Original issue reported on code.google.com by original...@gmail.com on 31 May 2010 at 12:08

Attachments:

• ArduinoTrace.JPG

[GoogleCodeExporter]

Just wired in a phonojack so I could plug in video or audio signal for a 
camera. 
Unfortunately I get the same result as in the picture above. All wires are 
soldered 
to the contact and have less than 0.2ohm resistance.

Original comment by original...@gmail.com on 31 May 2010 at 11:30

[GoogleCodeExporter]

With pins no-connected, the arduino gives erratic readings. It's how it's in 
the arduino docs regarding analogRead. Connecting to ground should give you a 
zero reading.

Original comment by david.ko...@gmail.com on 25 Sep 2012 at 6:46

• Changed state: Fixed