Multiple sheet schematic in Kicad? - Page 1
Forum section: electronics / general

author: opampsmoker
author_rank: Regular Contributor
timestamp: October 27, 2020, 08:10:30 pm
content: Hi,I have 4 sheets in my kicad schematic.Kicad has made a "sub-project" for the three added on sheets.Is this right?It feels unwieldy. I presume i have to push each separate sheet through to PCB?

author: golden_labels
author_rank: Super Contributor
timestamp: October 28, 2020, 03:33:04 am
content: Is each of them describing a separate PCB?If yes, this is ok — after all you will generate separate netlists, footprint assignments, PCB files, gerbers and probably other files.If no, you probably want hierarchical sheets. There are a few buttons on the toolbar to create them and the associated labels.

author: opampsmoker
author_rank: Regular Contributor
timestamp: October 28, 2020, 07:18:42 am
content: Thanks,Incidentally, is there a way of having multipel sheets in a schematic without having heirarchical sheets?.....i want to keep the heirarchical sheets for small subcircuits which are repeated often. Though i still want extra sheets which are not heirarchical.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 28, 2020, 09:27:14 am
content: Does KiCad really still have that limitation that no schematic can span multiple pages without having each individual page as a hierarchical block?

author: hli
author_rank: Frequent Contributor
timestamp: October 28, 2020, 10:13:37 am
content: https://docs.kicad-pcb.org/5.0/en/eeschema/eeschema.html#flat-hierarchyHaving that one root schematic is not so much of a hassle. Would be nice to skip it, but adding it is also not a great deal. There are more important things to improve.

author: AndyC_772
author_rank: Super Contributor
timestamp: October 28, 2020, 11:16:08 am
content: So, say I'm developing an 8 channel product, in which each channel is 3 pages' worth of circuitry.In OrCAD, I create a 3 page schematic which contains the circuit for each channel. That schematic uses off-page symbols (or even just common net names) to link the nets within each channel, and hierarchical ports to expose the signals that need to be visible at the top level.Then, I create a top level schematic which includes 8 identical instances of the per-channel circuit (ie. 8 identical blocks), and joins them to the common power, processor etc.How would that design be done in KiCad?

author: MitjaN
author_rank: Contributor
timestamp: October 28, 2020, 03:50:07 pm
content: I agree that lack of support for multipage same level hierarchy in KiCad is somewhat limiting, but we get what we pay for.If you have multichannel design, you'll probably want to replicate layout (AD rooms, I don't know what is called in OrCad). I'd go this way:1. create 8 hierarchical sheets in the main (root) sheet to hold the channel schematics. Point each sheet to the same schematics file2. in each channel sheet create 3 hierarchical subsheets where you split the schematics for one channel. You'll have to link the nets via hierarchical labes and connectors though. Using global labels will not work as you have a multichannel design.

author: golden_labels
author_rank: Super Contributor
timestamp: October 28, 2020, 04:10:04 pm
content: Ashlihas noted above, you can have as many sheets as you want. KiCad is also supporting global labels, which are shared among all sheets. All additional work you have to do is add a single root sheet that will group them all.

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 10, 2020, 03:22:37 pm
content: Quote from: MitjaN on October 28, 2020, 03:50:07 pmI also find that quite limiting. Or at least I used to think that.The plus side (even if that might not have been the original reason) is that it forces you to design your schematics in a more hirerarchical way (if you use that properly), which IMO (but probably not everyone will agree) is a good thing.So each "sheet" should be self-contained, and actually more easily reusable (it looks cleaner and better than just copy-and-pasting.)Now the fact each hierarchical block can't span several "sheets" is still limiting, but here again the plus side is that it forces you to split your design into blocks of reasonable size and thus, more easily manageable and less prone to mistakes.Of course, YMMV.