kicad-developers team mailing list archive

[Andy Peters <devel@xxxxxxxxx>]

> On Nov 4, 2015, at 4:11 PM, xarx@xxxxxx wrote:
> 
> Andy,
> 
> I've put my comments in to the text below.
> 
>>> I'm not an EE professional, I'm an EE hobbyist. And my ideal tool would
> allow
>>> me to draw a schema and allow me to copy it to a document or to publish it
> to
>>> internet. And then by extending it a little bit I could use the same
> schema
>>> for simulations (which may then force me to modify the schema and publish
> it
>>> again). And when I'm satisfied, then I would amend the schema with new
>>> information (without the necessity to draw and maintain another copy of
> it)
>>> and use it for Pcb creation. I don't know whether there are any quirks
> when
>>> performing this workflow in large scale, but in an amateur scale I see no
>>> problems with that. KiCad allows one to omit selected components from
> netlist
>>> exports, or from Pcb creation, or from both.
> 
>> Well, you say use the same schema for simulations (which may then force me
> to
>> modify the schema  which sounds like youre basically creating two
> different
>> schematics. And thats fine. What I argue against is attempting to use the
>> _same_ schematic for both SPICE (or other) simulation and PCB layout.
> 
>> What I think happens with most designs is that there is only a small part
> which
>> needs to be simulated. Consider a mostly-digital design with DAC on it, and
> you
>> want to simulate the DAC output filter. Its easiest to pull out the filter
> and
>> simulate it separately, and when youre happy, copy that design (with proper
>> component values) back to the main design. Yes, there is some amount of
>> self-discipline involved.
> 
> Nope. When I need to understand a part of a circuit, I model it separately.
> But then I try to simulate the circuit as a whole. But my circuits haven't
> been big, I'm using KiCad for a couple of months maybe.

Since my designs are either all digital or mixed-signal, it’s impossible for me to simulate the entire circuit with SPICE.


>> For documentation, I use OS X, so the Print command enables PDF output for
> free.
>> On Windows you can install something like CutePDF which creates a virtual
>> printer that outputs to PDF files.
> 
> I'm interested in GIFs or PNGs, not in PDFs. I plot the schema into clipboard,
> then I crop it and paste it into my personal notes app. Unfortunately, KiCad
> does not have the ability to copy a part of a schema into clipboard directly.
> I use KiCad on Windows 7.

As I noted, on the Mac, one can print directly to a PDF, and then using Preview, that PDF can be edited (standard cut/copy/paste) and bits can be saved as JPG or PNG or whatever. I think it’s fine for the application (Kicad, in this case) to hand off this stuff to the operating system.

But you are correct about Kicad not using the OS clipboard for cut/copy/paste. That has been commented on in the past, mostly by users who wish to copy between schematics.


>>> Concerning LTSpiceIV, I found it an excelent simulator with a terrible
> editor.
>>> That's why I wouldn't mind editing netlists for LTSpice somewhere else -
> in
>>> KiCad :-) But for now I'm happily using KiCad + NgSpice.
> 
>> No doubt  the schematic capture for LTSpice is rather dreadful, with
>> non-obvious commands for everything. (It makes EAGLE look user-friendly and
>> standard.) I printed out the cheat sheet with the key commands because I can
>> never remember them. But LTSpice beats other tools is that you can click on
> a
>> net and it plots the voltage waveform for that net. Click on a component,
> and it
>> plots the current through that component. I honestly dont know if the
>> KiCad/NgSpice combination does that.
> 
> eSim (which is basically a wrapper over KiCad and NgSpice) allows something
> similar. But instead of placing a probe directly in the schema, you check the
> nets you want to plot in a list.
> 
>>> So, perhaps your way and purpose of using the tools is different from
> mine?
> 
>> Oh, yes, certainly years of working in a production environment ingrains
> some
>> habits that are impossible to shake. Thankfully, Kicad easily accommodates
> those
>> habits, and I think thats because the guys who started the project and
> continue
>> to maintain it need to do PCB design in a production environment. Much of
> what
>> is needed for production is overkill for the hobbyist, but I honestly think
> that
>> if Kicad didnt appeal to the professionals it would be yet another
> half-baked
>> open-source CAD program and not the useful tool it has become. 
> 
> Without doubt! But the problem of professional tools is usually their steep
> learning curve. You have to understand the tool almost completely in order to
> be able  to use it even as a beginner. This is unfortunate.

Well, that is indeed the case. Learning a 3D CAD program when you are not an ME is painful. Learning what Photoshop can do so you can best exploit its features takes time and effort. There are still features of Apple Logic Pro that I don’t know about, and I’ve been using it for years for recording and mixing. As Uncle Ben Parker said, with great power comes great responsibility. In this case, the responsibility is for the user to invest the time and effort to learn the program. Training helps, either self-directed with tutorials and videos, or training classes offered by vendors.

(Usage note: Actually, it’s a shallow learning curve that is difficult. Given that the X axis is time and the Y axis is knowledge or skill obtained, if you learn more faster, then the slope of the learning line is steep. If it takes awhile, then the learning curve is shallow. Next, I shall rail against LCD Displays, ATM Machines and PIN Numbers.)

-a