Re: [CAD_CAM_EDM_DRO] Re: PIC DRO Dreaming

>
> From: Paul Devey <paul_devey@...>
>
>
> > From: "Paul Devey" <paul_devey@...>
> >
> > You bring up some interesting topics:
> >
> > - Display: Their are some cheap parallel and serial displays out on the
> > market for the hobbiest these days;
> I agree the LCD displays are cheap.
>
> I ordered a few 4 line by 20 column displays for 6 bucks a few days ago.
> There are several cheap options.
>
> I admit it is personal preference, but in this situation. I'd lean more in
> the direction of a light generating device.
>
> LED or gas plasma.
> I saw a blue Gas plasma display a few days ago using the standard LCD
> interface for $12.00
>
> It may sound strange, but I personaly would prefer some physical seperation
> between the Axis displays, rather than all together, IE. 3 seperate
> displays rather than one large one.
>
> LED segement type displays are going to be a LOT tougher than an LCD or
> gas plasma display for what it's worth.
>
> [Paul Devey]
>
> I agree. 3 separate gas plasma displays.
>
> I think you want to have a standard interface so people can hook whatever
> they want.

What the best "Standard" interface would be will end up depending on
What features this thing will have.

If the only thing it will really need to display is 6 or 7 digits, that is
a whole different thing than text, menus, and descriptions.

The former would be easily done by spitting out standard 7 segment driving
signals. People then have the option of anything from 1/4" tall digits
for a small desktop mill to 3" tall displays you can read from 100 yards.

Electronics goldmine has a 7 digit array with 4 other colored LED bars along
the bottom for a buck. The digits are about 1/3" tall.

>
> Have you seen those little dot matrix displays? They are some type of gas
> display I think. HP uses them on some of their test equipment. Droool!

I ordered a batch of HP Matrix displays last week, I hope to get them in
the next few days.
The ones I ordered are sunlight readable LED and have 4 5X7 digits/module
You should be able to stack 2 together for 8 digits.
$1.00

Electronics goldmine has 10 char X 2 line Gas plasma displays built
for cars.
They are the bare modules, and I don't know exactly what is required to
drive them.
They are matrix type as well, and the digits appear to be about 1/2" tall.
$2.00

> >
> > - Level of difficulty: Reading the Quad inputs would not be diffucult.
> Nor
> > Displaying the results;
>
> The only issues I can think of right of would be the floating point
> math, even if nothing more than counting clicks, and multiplying by
> .00045354, tracking everything to 5 or 6 digits, and rounding it off
> to provide the current displayed value to .0001 or whatever.
> [Paul Devey]
>
> This could be an issue if you are rapidly traversing in all three
> dimensions at once.

The way I see it, you can only read the display so fast.
I would modularize the display logic so that is updates are driven
from an interrupt based on a timer, and are a secondary process, Missing
pulses because you were busy updating the display is not an option.

For the most part, my brain could not deal with interpreting 3 quickly
changing axis displays anyway. maybe a few times a second on a good day.

> [Paul Devey]
>
> Two serial ports. One could be used to interface to displays. The other for
> sending info to a PC for redisplay or what ever. The second serial port
> could also be used for downloading code into one of the FLASH 8052
> controllers.

I would not run the displays thru a serial, as in RS-232, interface.

I adds a lot of cost, and on the other end is another embedded processor
that simply decodeds the data, and does what the main controller should
be doing in this case. IMHO.

My board will have flash. I have a bunch of 256K byte chips I intend to use.
I plan to allow jumpering or switching to select different banks.
The 8052 can't deal with more than 64K without major messing around, and I
figure a test/diagnostics program would be handy in on of those unused banks.

>
> I have a preference to having it written in a high level language. Easier
> to write and can be ported easily to other platforms.

I would agree, although it does push the cost and complexity up.

>
> Keeping it simple (KISS) is very important.
> >
> > - Skills: I could probably do it.
> >
> > - Time: I will ask the wife and my 3 month old if I am aloud to spend
> time
> > on this. I think their are people on this group who could do a better job
> > than I. Anyone lurking out their who should reveal themselves? Don't be
> > afraid to look stupid. I do it all the time.
> >
> I'm trying to get an 8052 Board together, that is my first use for the
> machine I'm trying to get together, to build the boards.
> it's a real catch-22 situation.
>
> They are not nearly as compact and simple as a PIC, but on the other hand
> they have a lot more options as far as memory and C compilers.
> The down side is aside from ~256 Bytes of RAM, and No ROM, all the
> 128K or RAM/ROM are external chips you need to mount of the board.
> The up-side is the option of that much code and RAM means you could
> put the whole machine controller on there if you want.
>
> I just ordered some for 88 Cents.
>
> On the other hand my first, project with a PIC took about 4 hours
> starting from scratch, and the only thing I had to add was an Xtal.
>
> [Paul Devey]
> Their are a few 8052 proto-boards and hobby boards sold by companies.
> Circuit Cellar is a good place to look. Saves time and costs less than
> $100.00.

Yea, but I still want the flexibility of quickly changing and adding to
the board itself.
Granted, you can add a second daughterboard or something, but I like the
flexibility of building the board.
I'm sure a rational cost analysis would say different, but I enjoy doing
it, and will feel better with the result, (I hope).

Marc