Evil Mad Scientist

can you provide some links for visual diffing tools? 90% of the programs I write are PLC programs in the IEC 61131 function block language. I would love to be able to diff and merge.

PLC processors have come down so much in cost we have gone to a modular architecture where we have multiple CPUs in a plant each running an independent machine or part of the plant process partly so that one programmer can work on the program for 1 CPU without having to merge another programmer's changes.

I thought this could be useful if I could use the PLC programming software (Schneider Unity) to export PDFs of the function block diagrams: http://www.evilmadscientist.com/2011/improving-open-source-hardware-visual-diffs/

I thought I might be able to get this open source PLC programming software which includes a function block renderer to read the unity XML program exports and then I could render the function block sections myself and diff them: http://www.beremiz.org/doc

Here is the only real product I've ever seen which has a module for matlab simulink diffing: https://www.diffplug.com/

Schneider does have the UnityDiff tool which has come a long way in the last couple years and it does pretty decent diffs but there is no way to generate them automatically that I know of. I have to open both versions of the program I want to diff and then run the diffing tool. Then the visual diff output can't be exported out of the unitydiff program. printing doesn't work. I should make some feature…

Ah nice, hadn't seen those two. The first one I came across was [1] and I have been fascinated with the idea ever since. I kind of agree with Dave Vandenbout [2] though in that it might not scale. I kind of shifted my fascination towards using code to do PCB designs and giving talks about that [3].

Best practices, it's a good idea, but it is hard enough to get people to do the minimal thing that I came up with for Kitspace and I think only certain kinds of people will read a best practices guide. At the Global Open Science Hardware Gathering [4] we are trying to come up with more general best practices for open source hardware though and doing a more focused one for electronics would be worthwhile anyway.

About attending OHS, not unless I can get some travel funding :(

[1]: https://www.evilmadscientist.com/2011/improving-open-source-hardware-visual-diffs/
[2]: http://www.xess.com/blog/schematics-really/
[3]: https://fosdem.org/2018/schedule/event/cad_pcb_code/
[4]: http://openhardware.science/gosh-manifesto/

Not the one I'm most proud but at least this one I can explain.

I initial did it to help a friend who wanted to customize and sell bycicle bells. since most printing techniques are made for flat surfaces this creates an interesting challenge.
The solution I eventually arrived at involves a pen plotter and a custom fixture. There's actually a article about it here: https://www.evilmadscientist.com/2019/bike-bells-with-axidraw/

And by the way, the obvious way to produce them would probably using transparent stickers a heat gun an a coat of varnish but where's the fun in that.

> To create his pictures, Bosch uses a computer program toconvert a drawing (or painting or photograph) into a scattering of dots

I think Bosch is using AJ Secord's work here:

https://cs.nyu.edu/~ajsecord/stipples.html

I'm also wondering if EMSLabs got the idea from him, or the other way around:

http://www.evilmadscientist.com/2012/stipplegen-weighted-voronoi-stippling-and-tsp-paths-in-processing/

EDIT: Also, plenty of other people have tinkered with this since, for example:

https://www.mattkeeter.com/projects/swingline/

https://github.com/repwolfe/stippling

It can be done:

https://www.evilmadscientist.com/2016/6502/

is a minicomputer implementation of the 6502. You can also make a "soft core" than can be uploaded to an FPGA, see

https://en.wikipedia.org/wiki/Soft_microprocessor

Some of those are open source. Probably the simplest CPU architecture for the CPU hacker is

https://en.wikipedia.org/wiki/Transport_triggered_architecture

which is not only easy to design, but lets you add custom processing units such that you can codesign the chip with the software it runs.

"The `paperclip computer` was introduced in 1967 in a book called How To Build a Working Digital Computer by Alcosser, Phillips, and Wolk. The book describes how you can build a simple computer with things around the house, like paperclips for switches, and a tin can for drum memory."

This sounds pretty cool, and possibly worthy of its own post.

http://www.evilmadscientist.com/2013/paperclip/

Apparently not first, though.