Linux (and Windows) electronics experimenters

[markw at mohawksoft.com (markw at mohawksoft.com)]

> markw at mohawksoft.com wrote:
>> I want to make a small dongle sort of device that you plug into your
>> computer's parallel port, it will have a number of digital input and
>> output
>> ports. I have a couple ideas about the programming API and software
>> support
>> set.
> Actually, I built something like this about 15 years ago for the PC. A
> parallel port has something like 12 output lines and 5 input lines. I
> set it up where the top 4 outputs would switch 8 multiplexers on the
> inputs & 8 on the outputs, allowing one to get up to 64 outputs and 40
> inputs. I then wrote a simple piece of software that would display a
> scrolling chart of the I/O states (histograph) and allow you to use the
> F-keys to change the output states (F1-F8 for the physical, F9-F12 for
> the multiplexing, I think). It worked pretty well, but was pretty slow
> for any sort of real-time stuff. I only needed it for a single project
> though, so I didn't spend all that much time optimizing it. It was
> actually alot of fun. I'll look around and see if I can find my
> schematics for you (I'm moving right now, so they should turn up).

I don't need the schematics. I have one in my head right now. (Mostly just
a PLD) What I wanted to accomplish was to get a very specific market, the
people who know what TTL is, and how to build stuff with it.

The trick, I think, is the software. Many hardware experimenters are not
*very* good with software. Also, many of the hardware devices I can see on
the market have either too many features, or are not flexable enough.

This device will basically have a few built in I/O ports, an I2C
connector, and an expansion bus. The I2C output can be used with most all
I2C devices as well as the Velleman K8000 type board. The I/O ports will
be usable on the dongle, and the expansion bus will allow a number of
add-on boards.

The target price is $19-$29 dollars. The software will be "EASY" to
program and run under Windows or Linux (maybe even *bsd)