Subject: Re: Looking for A/D & digital I/O interface for NetBSD system
To: Ken Hornstein <>
From: Herb Peyerl <>
List: current-users
Date: 11/07/2005 11:17:00
On 7-Nov-05, at 11:08 AM, Ken Hornstein wrote:
> 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.

True to my form; I've often done well dumpster diving around places  
that deal in PC104 stuff... This sort of stuff gets pitched on a  
regular basis and you might be able to put together a nice little  
PC104 NetBSD system.  I think one of our long time NetBSD users in  
the bay area deals in PC104. Maybe he'll speak up.

Otherwise, what I've done is used an old Atmel AVR board that I had  
lying around from another project which has Optoisolated inputs and  
SSR'd outputs.  I pulled a couple of Opto's off to use the inputs for  
A/D... Then a little bit of extant C code converted to provide a  
little CLI on the serial port and I can query/set any of my I/O's. I  
hook that up to a NetBSD box via serial and I'm good to go.  I know,  
it's not quite as elegant.