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Most of your post is Greek: tracks, vias, copper zones. I'm not sure how anyone can make an abstract design for an entire circuit board from scratch, it how to

Most of your post is Greek: tracks, vias, copper zones. I'm not sure how anyone can make an abstract design for an entire circuit board from scratch, it how to put one together.

adwn 10y ago
> Most of your post is Greek: tracks, vias, copper zones. I'm not sure how anyone can make an abstract design for an entire circuit board from scratch, it how to put one together. I do not understand what you're trying to say.
- Animats 10y ago
  (Comment moved up in tree as requested.)
  - deleted 10y ago
    [deleted]
ZenoArrow 10y ago
Forget about the terminology for a second. If you want to get a general understanding of circuit design, think about it in terms of connecting points. The London tube network is a good analogy for this. When starting out designing a circuit, you think only of which points need to be joined together. This is similar to the simplified tube map that many people are familiar with: http://www.bbc.co.uk/london/travel/downloads/tube_map.html http://www.bbc.co.uk/london/travel/downloads/tube_map.html However, that map only represents a simplified version. The real geographical map looks more like this (this is still simplified as it doesn't show information about the height/depth of the tracks): http://www.tubemapcentral.com/mythset/geomap.jpg http://www.tubemapcentral.com/mythset/geomap.jpg It's the same with circuit design. You start off with a simplified version, but the physical version is frequently more complicated because you have to work over multiple 'layers' in order to stop wires that cross over each other that shouldn't be connected from touching each other. That's where things like 'vias' come into play (vias are the points at which layers of a circuit board are connected to each other).
JshWright 10y ago
Well, I do know a Greek guy who has done some PCB design... https://www.stavros.io/posts/emergency-food-button/ https://www.stavros.io/posts/emergency-food-button/
Animats 10y ago
This is Hacker News. Some knowledge of hardware is expected. But I'll describe KiCad's workflow. First, you draw a schematic diagram. This has blocks and symbols for all the components. You place part symbols, which come from a library. Part symbols have a reference ID such as "R15", which you have to set, and you can also set such information as the actual part number in a catalog, which will be used later. The part symbols library has most standard components, but you'll probably have to draw some symbols of your own. There's a draw program for drawing symbols for new components. (The schematic editor is OK, but the symbol drawing program is a crappy draw program.) Then you run the design rule checker. This tells you if you forgot to connect a pin, or connected two outputs together. It's sort of like "lint" for schematics. It doesn't know anything about electronics; it's just a topology check. Then you run a spreadsheet-like program which, for each part, assigns a "footprint" to that part. The "footprint" is the pattern of copper pads and holes on the PC board where that part goes. Many schematic symbols map to one footprint - all 8-pin SOIC-form packages have the same footprint, for example. Sometimes you need to add a new footprint, and there's a draw program for that, different from the schematic draw program. (It's a crappy draw program.) After that, you click the "NET" icon, and the schematic program generates a netlist. This is a text file with just the part info and wiring topology. You can also get out a bill of materials (BOM) file at this point, for ordering parts. Now PC board design begins. This is a separate program. You start by importing the netlist. There can be errors at this point - missing footprints and such. You may have to go back to the schematic editor. You can keep both open at once, change the schematic, and generate a new netlist. At this point, you have a display showing all the parts spread out more or less randomly (there's an auto-place function which does this, not very well), with lines showing where connections are needed. The lines are just straight lines between things that need to be connected, not useful printed circuit board traces. This is called a "rat's nest". Now you drag parts around until you have a workable parts layout. (Some parts need to be close to other parts for electronics reasons. You may want connectors and such in specific places.) Then comes connecting up the parts. There's an automatic routing program for this, but it's not very good. (That's what you pay the big bucks for in the high-end EDA systems.) Mostly you draw tracks of copper to connect up parts on the various board layers, and use vias, connecting holes through the board, to connect through layers. This is manual, but the program checks you - you can only connect things that the netlist says should be connected. The program won't let you make a wrong connection. There's also a design rule checker for clearances between wires and such. This is a slow, fussy process. Squeezing in all the tracks can be tough, and previous tracks may have to be moved. The tighter you design your board, the harder this is. Once everything is connected properly, and the design rule checker says there are no problems, you generate "Gerber files" for each board layer, and a "drill file" which defines where holes go. These are industry-standard files. You send them to a board design service and boards come back in a few days. They're made by photo-etching and CNC drilling, and while it's possible to do this yourself, it's not worth the trouble because custom board fab runs now start around $21. So that's how you make a basic PC board with KiCAD.

Most of your post is Greek: tracks, vias, copper zones. I'm not sure how anyone can make an abstract design for an entire circuit board from scratch, it how to put one together.

adwn 10y ago

> Most of your post is Greek: tracks, vias, copper zones. I'm not sure how anyone can make an abstract design for an entire circuit board from scratch, it how to put one together. I do not understand what you're trying to say.

Animats 10y ago
(Comment moved up in tree as requested.)
- deleted 10y ago
  [deleted]

ZenoArrow 10y ago

Forget about the terminology for a second. If you want to get a general understanding of circuit design, think about it in terms of connecting points. The London tube network is a good analogy for this. When starting out designing a circuit, you think only of which points need to be joined together. This is similar to the simplified tube map that many people are familiar with: http://www.bbc.co.uk/london/travel/downloads/tube_map.html http://www.bbc.co.uk/london/travel/downloads/tube_map.html However, that map only represents a simplified version. The real geographical map looks more like this (this is still simplified as it doesn't show information about the height/depth of the tracks): http://www.tubemapcentral.com/mythset/geomap.jpg http://www.tubemapcentral.com/mythset/geomap.jpg It's the same with circuit design. You start off with a simplified version, but the physical version is frequently more complicated because you have to work over multiple 'layers' in order to stop wires that cross over each other that shouldn't be connected from touching each other. That's where things like 'vias' come into play (vias are the points at which layers of a circuit board are connected to each other).

JshWright 10y ago

Well, I do know a Greek guy who has done some PCB design... https://www.stavros.io/posts/emergency-food-button/ https://www.stavros.io/posts/emergency-food-button/

Animats 10y ago

This is Hacker News. Some knowledge of hardware is expected. But I'll describe KiCad's workflow. First, you draw a schematic diagram. This has blocks and symbols for all the components. You place part symbols, which come from a library. Part symbols have a reference ID such as "R15", which you have to set, and you can also set such information as the actual part number in a catalog, which will be used later. The part symbols library has most standard components, but you'll probably have to draw some symbols of your own. There's a draw program for drawing symbols for new components. (The schematic editor is OK, but the symbol drawing program is a crappy draw program.) Then you run the design rule checker. This tells you if you forgot to connect a pin, or connected two outputs together. It's sort of like "lint" for schematics. It doesn't know anything about electronics; it's just a topology check. Then you run a spreadsheet-like program which, for each part, assigns a "footprint" to that part. The "footprint" is the pattern of copper pads and holes on the PC board where that part goes. Many schematic symbols map to one footprint - all 8-pin SOIC-form packages have the same footprint, for example. Sometimes you need to add a new footprint, and there's a draw program for that, different from the schematic draw program. (It's a crappy draw program.) After that, you click the "NET" icon, and the schematic program generates a netlist. This is a text file with just the part info and wiring topology. You can also get out a bill of materials (BOM) file at this point, for ordering parts. Now PC board design begins. This is a separate program. You start by importing the netlist. There can be errors at this point - missing footprints and such. You may have to go back to the schematic editor. You can keep both open at once, change the schematic, and generate a new netlist. At this point, you have a display showing all the parts spread out more or less randomly (there's an auto-place function which does this, not very well), with lines showing where connections are needed. The lines are just straight lines between things that need to be connected, not useful printed circuit board traces. This is called a "rat's nest". Now you drag parts around until you have a workable parts layout. (Some parts need to be close to other parts for electronics reasons. You may want connectors and such in specific places.) Then comes connecting up the parts. There's an automatic routing program for this, but it's not very good. (That's what you pay the big bucks for in the high-end EDA systems.) Mostly you draw tracks of copper to connect up parts on the various board layers, and use vias, connecting holes through the board, to connect through layers. This is manual, but the program checks you - you can only connect things that the netlist says should be connected. The program won't let you make a wrong connection. There's also a design rule checker for clearances between wires and such. This is a slow, fussy process. Squeezing in all the tracks can be tough, and previous tracks may have to be moved. The tighter you design your board, the harder this is. Once everything is connected properly, and the design rule checker says there are no problems, you generate "Gerber files" for each board layer, and a "drill file" which defines where holes go. These are industry-standard files. You send them to a board design service and boards come back in a few days. They're made by photo-etching and CNC drilling, and while it's possible to do this yourself, it's not worth the trouble because custom board fab runs now start around $21. So that's how you make a basic PC board with KiCAD.