FidoCadJ: a drawing utility for discussion groups and forums dedicated to electronics

On Sat, 5 Feb 2011 08:20:27 -0800 (PST), Darwin wrote:

Most of us use LT Spice, and just post the ascii schematic file here. Then people can not only see it, they can play with the simulation.

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John

Dear John, I know LT Spice (and I noticed it was used here and in sci.electronics.design): it is a wonderful tool, but it has an entirely different goal than FidoCadJ's. The latter for example does not simulate circuits and is more a quite simple 2D vector graphic tool. One of the problems I have is that I can not see the circuit you posted since I am using MacOSX on an old PPC machine and it is not very practical for me to use LT Spice (even if I sometimes need Windows on my Intel-based laptop to use Altium Designer at my work). I believe who is using Linux would experience similar problems. But the point is not entirely that. Other people will appreciate that FidoCadJ is open source and that the format is well documented. On another point of view, we are on Usenet now, but I have seen the FidoCadJ format handled on some forums thanks to FidoReadPHP and I was the first to be surprised by the success it had.

BTW, I still have some step recovery diodes you sent to me a few years ago. I played with them in a sub-nanosecond rise time pulse generator and they were very useful. Thanks again for your help!

Best regards,

Davide

Unfortunately, engineers are usually forced to run Windows. Too many tools require it.

I'd love to have a really good drawing program, for block diagrams and timing diagrams and general line work. I've been using Visio, which works but is klunky. I've never got around to learning Autocad.

SRDs are great fun, but hard to get. There are only two or three that are stocked parts, available through distribution, namely the MAcom SOT23's, which are a bit slow. Seems like everybody else just stocks wafers and packages parts to order, if you beg and plead enough.

Some other parts are accidental SRDs, like varicap diodes maybe. That would be cool to experiment with some day.

John

That is unfortunately true! It must be said that FidoCadJ is probably less useful for an engineer than to an hobbyist, since an engineer has much more powerful tools for such kind of things. Having said that, I know some engineers who appreciate FidoCadJ too :-)

Probably, FidoCadJ is not a good tool for such kind of things, even if for some quick sketches it may still be useful. For a lot of time, I used Corel Draw (on Windows), then I switched to Open Office Draw, but I find it rather klunky. I should give a try to Inkscape a day or another. FidoCadJ is quite good for preparing schematics meant to be included in documents (CADs such Altium Designer are just horrible for that). I use quite often LaTeX and FidoCadJ drawings can be exported and included via the PGF graphic system. I find it quite satisfying from a typographical point of view. With a WYSIWYG editor like Word, results are less pleasing since you must first export as a PNG image and then include it, but it is still way better than other systems.

I recall that I obtained a few samples from Aeroflex-Metelics and I played with their MMD840 obtaining some 100 ps rise time 10%-90%. It was measured with a 40 GHz sampling oscilloscope, so the measure was a little bit affected by the jitter of the trigger generator.

I have heard that, but I recall that the results I got with some varicap diodes I had in my junk box were not very encouraging. I remember also I was trying some bipolar transistors in their avalanche region, somewhat inspired by a Jim Williams' application note. I did not measured precisely the rise time I got (I believe some

Freelance 4.0 for DOS. Best technical cartoon-drawing program ever made. Runs well under emulation too.

Cheers

Phil Hobbs

WOW. You guys are way advanced. I still use Paint to draw schems. Course you have to create the components.......

The problem is that Paint is a bitmap based drawing program. This will do only for tracing some low resolution schematics and sketches. Bitmap is OK for retouching photos (well, not with Paint, I guess), but it is not very well suit for schematics. From a typographical point of view, it is way better to use some vector-based drawing program, at least if possible.

Paint can be pretty effective for the occasional schematic, if you already have the general circuit drawn (on scratch paper, say) and just want to create a decent drawing for publication. The trick is to confine yourself to a single resolution/scale and maintain a "drawing" of individual components: resistor, capacitor, PNP, NPN, diode, op-amp, etc. Then you keep a copy of this drawing open next to the one you are working on. When you want to add a component you select it in the component drawing, and copy-paste it to the target. You can rotate or flip it at that time. Connect as needed with the line-drawing tool, using SHIFT to maintain horizontal and vertical lines.

One advantage of Paint is that you can do pretty much anything you want, without learning a suite of arcane methods for a special-purpose CAD drawing tool. Some of the vector-based CAD tools have pretty crude-looking fonts, for example.

Plus, many folks are already familiar with how to get around in Paint, which counts for a lot if you are only doing an occasional drawing.

Best regards,

Bob Masta DAQARTA v6.00 Data AcQuisition And Real-Time Analysis

Using Paint to draw schematics is like transporting lumber using only a bicycle. It's a great stunt and a tremendous workout but it is not very effective or fun.

In our world, a flatbed truck costs as much to purchase and run as does a bicycle, is much faster and easier to drive and gets the job done quickly, correctly and *much* more pleasantly.

My advice: Download LTSpice for free.

:)

--Winston

On which planet can you buy a flatbed truck for fifty bucks?

Thanks, Rich

If you want to publish anything decent, you may work at least at a quite high resolution in dpi or instead the result would be not very professional. The result may be OK for a webpage, but probably not for printing.

You may defintely give a try to FidoCadJ instead of Paint. I am involved in the development, so I can not be completely objective, but I heard a lot of people is perfectly happy with it: no arcane methods at all, just very simple drawing primitives and a collection of symbols which can be customized. If you want to retouch your drawings, you may export them in EPS, PDF or SVG and you still have a vector- based representation. Or else, you may export them in PNG or JPEG to obtain a bitmap version, which you may edit in Paint :-) If I am dubious FidoCadJ would represent a valid alternative for someone already using LT Spice, I am quite sure it is much better than Paint even for casual use if you seek a software to draw very quickly an electronic schematic or a simple PCB.

I've used Paint to put text annotation on bitmaps, but rarely for anything else.

You really need vector graphics for publication. Pictures inevitably get resized to fit the page layout; vector files look fine at any magnification, bitmaps don't. And LTSpice schematics aren't that great looking when printed.

It doesn't have to be fancy stuff--I use Freelance 4.0 for DOS, as I said already, for all my line drawing needs, and have for 20 years. It has zilch support for modern printers, but the old printer drivers produce excellent PostScript, which is easy to convert to anything. Everything I've published since about 1990 has been done with it. There are other simple drawing packages available that produce vector output.

Cheers

Phil Hobbs

I use paint fairly often to resize bitmaps. It's a lot faster and easier than firing up GIMP.

It's a pair of 'similes' Rich.

I was equating the bicycle to MSPaint and the flatbed truck to LTSpice.

Either program costs about nothing, but LTSpice is so much better suited to the purpose of electronic development and idea sharing that it is sad to contemplate someone struggling with MSPaint for those purposes.

Just like attempting to haul lumber on a bicycle. One can do it but one would be wasting one's valuable time.

--Winston