newbie needs help in IO

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Hi All,

I am pretty new to linux embedded. A mobile robot project I am working on
requires some IOs: 3 quadrature (single-ended) inputs. two 12 bit AD inputs,
one PWM output.  I want to use linux embedded with PC/104 hardware. I can
code in C or C++ and I want to avoid learnning assembly langrage if I can.
Do I have to write my own device driver for these IO boards? Is there any
company that sell the PC104 IO boards with linux drivers?

Thanks in advance.


Re: newbie needs help in IO
You can contact for their 'multi-q' I/o board.
Tried and proven in hundreds of labs in universities all around the world.
Great support. Runs in true real time. easy to use.

mention me if you want to.



Re: newbie needs help in IO
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One way you can approach this is, since this is embedded system and I
am assuming not on the network, you can run you program as root user,
this will allow you to access all the I/O ports so you don't have to
write any drivers.

The other way that we have implemented write a very simple driver that
allows you to access all the I/O ports.
This way you can use any hardware you like.
Hope this helps.

Andy R.

Re: newbie needs help in IO
You can get a board and support from

Simple as that.

Jay in Greensville,Ont.

Re: newbie needs help in IO
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Can't help you if your application specifies the use of embedded
Linux... (and based on the question you ask about device drivers
reflect why Linux remains a rare choice for real-world systems
interfacing with industrial I/O).

But if you have C/C++ programming capability, the following boards
from TERN would meet the requirements you specified in your post:

- first, if you can implement your own quad decoders through polling
of the input signals from your encoders, then something as simple as
the A-Engine would work:

The (former) x86-based Am188ES processor has integrated PWM outputs,
11 ch. 12-bit ADC, and plenty of digital I/O that you could use to
decode the quadrature inputs.  In low quantities, this would be priced

- second, the A-Engine is also compatible with the P100 expansion
board, which is available integrated with two HP2020 quadrature
decoders, to save yourself the trouble of dealing with the inputs via

Re: newbie needs help in IO

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FUD.  Maybe you consider embedded Linux "rare" because your product line
doesn't support it?

I've been working with embedded Linux in industrial control applications
(real time and not) since 1999 and I wasn't an "early adopter".


Re: newbie needs help in IO

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Definitely don't want to get into a religious/philosophical battle, so
let me apologize ahead of time and try to back out gracefully. :)
Embedded Linux is certainly in existence, and it is certainly popular
for a wide range of "industrial control applications".

I will just state that many applications that deal primarily with
responding to and controlling industrial-level interfaces (digital
I/Os, solenoids, relays, serial rs232/485, analog I/Os) also do not
overlap with environments that could really leverage the heavy
multitasking or other system services offered by Linux.

Re: newbie needs help in IO (CC Tang) wrote in message
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Care to explain why I answer sales inquiries and support questions all
day from our huge list of Linux users?  I'm a driver developer for a
PC/104 company (Diamond Systems) and according to our support poll,
50% of our users are currently implementing projects in Linux.  Rare?
Maybe when I started at the company a few years ago, but not anymore.

P.S. Since I'm battling Linux FUD I might as well pitch our products
as well. :-) /.  We have excellent Linux
drivers for all our DAQ products.

Re: newbie needs help in IO
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Correct me if I am wrong, but I believe PC104 systems only have
the equivalent of ISA interfaces, with no PCI, AGP, USB, etc.
Thus your products and drivers are not useful for the cheapest of
hardware, the common PC.

Please don't take this as a criticism.  I applaud your efforts.

Chuck F ( (
   Available for consulting/temporary embedded and systems.
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Re: newbie needs help in IO
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Right!  PC/104 really is orthogonal to the consumer PC market.  You
wouldn't ever want to buy a PC/104 audio board to add to your Athlon
consumer PC, or the reverse.

While the PC/104 expansion bus is ISA, this doesn't stop the CPU board
in the PC/104 stack from having all kinds of integrated devices like
USB, AC'97 audio, AGP 3D video, etc so usually you already have most
of the non-ISA features you need right on the embedded CPU board.

The PC/104 market is quite different from the consumer PC solutions
market.  If the project requirements call for a cheap, small computer
then there are plenty of "common PC" solutions out there.  However,
PC/104 is great when you need extended temperature ranges, vibration
tolerance, stackability in tight spaces, low power, big MTBF numbers,
lots of vendors selling compatable modules you can stack, extended
availability of "legacy" products, etc.

Your typical Athlon motherboard wont last very long if you launch it
into space, put it in a military vehicle, monitor oil pumps in the
Arctic circle, or try to buy more *exactly* like it 3 years later
because thats the only one the FDA certified for use in your medical
equipment. It'll fail at +70C, the vibration will knock the RAM right
out of the DIMM slots during launch, and Asus US sales will have
stopped making that mobo years ago... :-)

Hmm, I think this has gone a bit off topic.  Sorry.  Reply via e-mail
if interested in discussing further.

Re: newbie needs help in IO
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That's not true IMHO. I know that there are many projects moving from
VxWorks to Linux.


Re: newbie needs help in IO
What about using one ore several very small integrated processor(s)
(e.g. Ubicom 2022 some $10) to do the hardware I/O and connecting them
via Ethernet.


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