28BYJ-48 Stepper Motor and ULN2003 Driver Module

[vanepp]

@roboteach

Out of curiosity, I’ve been looking around and you produce a lot of parts: would you mind sharing your process of part creation/editing? (tools, steps, environment…) I’m specifically curious about how do you test small changes, because for me it is very time consuming just the simple repetitive steps that go from “updating the svg” until you can actually check the part in Fritzing. Maybe I should start a topic just for this subject…

This series of posts

Part creation howto part 1 breadboard and pcb

Someone in this forum post requested help to fix up a part. So while doing that I decided to record what I needed to do in order to fix the part to provide a tutorial to create new / fix broken parts. If you start from the Tarjeta S4A EDU.fzpz file posted in the above thread, you should be able to recreate my improved part posted in the same thread. I started by loading the original part in to Fritzing, that indicates breadboard is (at first look anyway) pretty good, but schematic and pcb are…

describe what I do. I have some tools (some published on github some not) that will create fzp boilerplate for connectors, (FritzingCreateFzpConnectors.py on gighub) and these 3 which need more work before they are ready for prime time

SvgRenumberConnectors.py
SvgSetConnectors.py
SvgSetConnectorsbb.py

SvgRenumberConnectors.py renumbers connectors in an svg. At present I modify the python code to do what I need on the fly, that needs to be generalized so it can be controlled from the command line.

SvgSetConnectors.py
SvgSetConnectorsbb.py

These two (SvgSetConnectors.py for schematic) and SvgSetConnectorsbb.py for breadboard and pcb) take an svg with the connector pins at the bottom of the svg, with the first connector labeled connectorxpin (I think connector anything works) and assigns the pins sequentially. SvgSetConnectors.py looks for a line followed by a rectangle (pin and terminal) where SvgSetConnectorsbb.py looks for only the connector and assumes everything after it is another connector. This allows me to move the pins and terminals in order in a svg without typing the pin numbers then run the svg through one of these to create the correct pin numbers. On large parts that saves a lot of time. Again the two scripts need to be merged in to one with command line options to control behaviour (after I finish the new version of FritzingCheckPart!)

@roboteach

I’m specifically curious about how do you test small changes, because for me it is very time consuming just the simple repetitive steps that go from “updating the svg” until you can actually check the part in Fritzing.

I don’t know of any shortcuts here. This is usually the most time consuming part and is covered in

Part-creation-howto-part-4-testing

Having completed all the files for the part in (and earlier): On to testing the part. First run it through FritzingCheckPart.py, the part checking script. This checks the syntax of the part for errors and fixes some things that Inkscape does for CSS compliance that Fritzing does not support. Those are: remove the px from the end of font-size elements. Replace CSS style commands with equivalent inline XML (bendable legs do not support style commands), and insure that a stroke-width value (whi…

in the tutorial series. Hopefully more can be done in FritzingCheckPart eventually, but I am having enough trouble just updating it to not have false positives so it can front end parts submission on github. A number of places it will sometimes complain about something that is in fact fine. For its original purpose, that is fine because the output goes to a human, but as a part of automated part submission, it is not.

edit:

Forgot this one:

@roboteach

another interesting question: how do yo generate the SVG line elements (used in the connectorXXpin parts of the drawings)? Inkscape can’t produce them (although, oddly enough, can manipulate them…).

Yes the line is an Illustrator construct but I like it. Both copy/paste and duplicate in Inkscape will deal with line, so I copy / paste from an svg that has one if there isn’t one and duplicate to get more once I have one. The schematic template uses them already and I often replace schematics with a copy of the template (which is the correct scale with the correct pins and terminalIds and the correct colors to match the graphic standard) instead of trying to correct an existing one in Inkscape.

Peter