#89

Could you say a bit more about this process? Are there PCB fabs which offer aluminium PCBs? I wasn’t aware of that. What are the options for text and graphics?
I went through a period of making quite a few eurorack modules and tended to laser-cut acrylic for panels, but aluminium would be hardier and convenient if already ordering PCBs for circuits.

#90

allpcb and pcbway do them (I prefer allpcb’s ali pcbs). Text and graphics are whatever you like! You can use the copper layer for colour or texture as well, but I tend to just use the soldermask and silkscreen layers and keep it black and white. I make a bitmap in photoshop and then import it into eagle.

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#91

Would you mind to share more detailed (beginner friendly:) process of how you do that or maybe you have an eagle example you ok to share? Sorry if I am asking for too much not sure if it Is appropriate:)

#92

There are loads of eagle examples on my github…

There’s a writeup from Emilie Gillet on the MI forum - have a search for it - that’s a good starting point for using eagle to do panels…

My GitHub:

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#93

Great, thank you very much! Gosh, Emily is like endless source of knowledge.

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#94

Does anyone have experience / suggestions for hand-drawn circuit boards? I typically use Eagle and the straight line tool to draw curved lines with a bunch of segments.

I’d love a tool that would allow me to work with a stylus while maintaining some level of schematic cross-checking. I’m guessing this doesnt exist but perhaps someone has tried this? @infovore’s mention of Cenon feels like it could be part of this process.

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#95

Cenon probably isn’t a fit there - there’s no cross-checking or owt, it just happens to be a vector tool that will export to Gerber. I found it useful for interacting with silking layers, but wouldn’t want to trust it on copper necessarily.

#96

i love that you think your current designs aren’t wiggly enough :slight_smile:

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#97

With a large enough export and import using something like bitmap2component you should be able to do your copper layer in any vector graphics tool setting the correct width/outline as spacing, clear/fill the outline to check spacing, export as high DPI into b2c… Then you can draw using the pen tool or pencil tool to get as squiggly as you like.

Edit: I guess this doesn’t have any checking either

#98

PCBModE ( https://github.com/boldport/pcbmode ) is an option that allows you to layout in Inkscape and export Gerbers, though I’m not sure if it does any cross-checking. It is developed by the people behind Boldport and I believe it is used to design all of their project PCBs: https://boldport.com/shop?category=Soldering+projects

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#99

This seems to be good news for FrontDesign users who prefer or need to draw their designs with other software:

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#100

Only problem with Schaeffer is their prices…
Just got a panel made worth the price of few diy modules.
Top quality i must say.

#101

Can someone explain FPGAs to me? Why are they so popular in music tech (Roland Boutiques, UDO Super 6, dadamachines Doppler)? I’ve read about them but don’t understand how customisable logic gates is really any different to what you do with an MCU

#102

I don’t know if I can give you a comprehensive answer, but in short: with FPGAs you can design your hardware almost as if you were handwiring individual logic gates and with that comes the ability to exactly tailor your hardware to your needs without any abstraction layer. So you can fully control for example the latency of your hardware. With MCUs you aren’t designing hardware but describe the function of your design. This is of course easier but doesn’t give you as much control. Because it will run on a general purpose processor the performance of your programm will be limited by it’s specifications.

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#103

Thank you, that’s a great explanation :slightly_smiling_face:

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#104

Performance benefits from FPGAs typically come from the ability to build massively parallel data pipelines with them. They generally wind up using a lot more chip area and operating at lower clock speeds than “hard” processors, so if you just synthesize an ARM processor or whatever on an FPGA (a “fabric” processor) then it will be much lower performance / clock speed, take more physical space on the silicon and have higher power consumption than a “hard” ARM microprocessor would. However, when using an FPGA for a specific signal processing application you can design a special purpose processor core that processes hundreds or thousands of samples on every clock edge and have a massive performance advantage over doing the same calculation on a general-purpose processor. This is part of why they’re popular for demanding DSP applications.

Another big advantage of FPGAs for certain embedded applications is I/O flexibility. If you have many other chips you need to interface with, especially if they have high speed parallel interfaces, you may have a hard time finding a microcontroller with enough I/O pins and SPI controllers and so on to meet your needs. With an FPGA you can synthesize as many independent peripheral controllers as you can fit in the fabric and can route dozens of I/O pins to chips elsewhere on the board. It’s pretty common now to find FPGAs in mass-market video converters / upscalers because they can easily interface with multiple video-rate ADCs that each have 10 or 12 bit parallel (and sometimes DDR) interfaces. Microcontrollers aren’t really commercially available that can handle this kind of thing. The LVDS capable pins that are common on FPGAs are also quite flexible and can be used for very high speed signalling applications (ethernet, PCIe, etc.) or even for interesting applications like implementing a sigma-delta ADC or DAC using a very simple external circuit.

To play to their strengths it is common for modern / high-end FPGAs to include a dedicated processor core cut into the silicon, like Xilinx’s Zynq system-on-chips that have an ARM processor on the same chip as a bunch of FPGA fabric. These parts will also typically have some other hard cores such as gigabit transceivers designed for ethernet / USB / PCIe / what-have-you – and these are usually general-purpose enough that you can use them for any of the above high-speed peripheral interfaces depending on your application / board layout.

11 Likes
#105

hey, how do we feel about CAD software for product design? first-hand experience with alternatives to solidworks?

starting to think about housing some of the projects i’ve been working on in altium and this is an area i don’t really know much about. i’ve done some 3d work in art programs (houdini, blender, unreal, etc) but haven’t used something like autocad since high school (~18 years).

also i begrudgingly dual-boot from linux to windows for altium, so if i can reasonably get by with freecad i’d be happy to hear that. like i said–i’m a total newb in this area and i’m mainly looking to avoid having to switch applications after getting comfy with one, not necessarily declare a best of anything.

anyways thanks for your opinion(s) in advance!

edit: oops, forgot to mention my intended target–to produce design files in order to prototype a reasonably large object meant to be placed on a desk and milled from some kind of billet

#106

I’m not super experienced in the many (many) cad options, but if you by chance have an ipad that’s pencil capable, Shapr3D has been the only programs that I’ve found to be easy to learn and fast to model with. not really applicable if your preference is linux, but now that this program will be migrating to macos with the new silicon change, the workflow is really appealing.

outside if that, I use a personal license for Fusion360 (which is free) and I rarely run into limitations for not using the paid version. Sketchup is very popular and great if your needs aren’t too complex (and it runs in a browser). FreeCAD seems really nice and probably sufficient.

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#107

(^ thanks for a superlative explanatory technical post, by the way)

to add:

one fun reason for audio synthesis in particular: in FPGA designs, the audio sample rate is typically closer to the clock rate, could be orders of magnitude higher than standard digital audio rates.

therefore bandlimiting is a less of a problem, allowing higher quality from simpler algorithms.

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#108

Fusion360 is pretty standard in makerspaces these days, so it’s often quite possible to find a local expert who can sit right next to you while you learn, and help you figure stuff out. It’s an extremely capable alternative to SolidWorks. It can do constraint-based CAD just fine, and it can speak to all the various additive and subtractive CNC machines. It can even do simulation of static stress, modal frequencies, heat, and thermal stress. It will also integrate with Eagle to provide 3D models of your component-populated PCBs, very handy for enclosure design.

1 Like