Subject: Re: Looking for A/D & digital I/O interface for NetBSD system
To: Ken Hornstein <kenh@cmf.nrl.navy.mil>
From: Nathan J. Williams <nathanw@wasabisystems.com>
List: current-users
Date: 11/07/2005 14:19:11
Ken Hornstein <kenh@cmf.nrl.navy.mil> writes:

> I'm looking for a relatively inexpensive box/card/USB dongle/serial
> port thing that has a few digital output lines and at least one A/D
> converter.  I need at least three digital outputs and only one analog
> input.  I know I could build such a thing using any number of
> microcontrollers, but I would rather buy something at this stage.  My
> idea was to hang this off of a Soekis box (running NetBSD of couse)
> which restricts things to USB or serial, but if there was something
> that was relatively cheap available in an ISA or PCI form I'd be
> willing to reconsider (I know the Soekris has digital I/O pins
> available, but I didn't see one that had any form of A/D on them).  I'm
> okay with writing a device driver for said device if that's what it
> takes, as long as some form of documentation is available.

The LabJack (http://www.labjack.com/) seems to be what people usually
suggest. It looks like some driver-hacking or at least ugen-parsing is
needed, but there's a Linux driver that looks pretty
straightforward. We support interrupt pipes on both input and output
(apparantly Linux doesn't), so kernel support likely isn't necessary
at all.

For ultra-cheapo input, though, you might look at buying a USB game
controller with analog sticks and splicing your analog signal in
there. Not so useful for output, unfortunately, but you'll typically
have 2 or 4 analog inputs and about 10 digital inputs.

        - Nathan