| ID: | 5972 |
| From: | rn...@igor2.repo.hu |
| Date: | Sun, 5 Mar 2023 08:08:56 +0100 (CET) |
| Subject: | [pcb-rnd] sch-rnd new: direct terminal-terminal connections |
| replies: | 5975 from Bdale Garbee <bd...@gag.com> |
Hi all, normally a graphical creation of a network is drawing a wirenet between two terminals. The wirenet can have attributes, such as "name" so you get named nets. gschem also allows direct terminal-terminal connections, without any wiring. To ease loading gschem/lepton sheets in sch-rnd, I've added support to terminal-terminal connections in sch-rnd as well. This means if you place two resistors in a way their terminals cross or touch, the connection is marked graphically and a new anon net is created in the abstract model. However, I strogly recommend against using this feature in new design. I think good practice is to always place a wire between two terminals. Details: 1. The major drawback is that you can not easily name that net created that way. There is a special case when this is not such a big problem, tho: when one of the participants is a rail symbol (e.g. Vcc or gnd) that automatically names the net 2. Unlike gschem's, our terminals don't have one specific "sensitive" endpoint for conenctions, but the whole terminal is sensitive, so if you get any terminal-terminal crossing, that's a connection. 3. Unlike in gschem, our connections are always indicated explicitly, so if you think you arranged two terminals in a way they should be connected but you don't see the little green circle showing up, and you don't see a net in the abstract model connecting the two terminals, that's probably a bug. 4. There is an ugly corner case: if you arrange more than two terminals to cross, depending on the arrangement, sch-rnd may indicate more than a single connection; typically indicating pairwise connections between the participants. This also triggers a compiler error of multiport merging. I have this on TODO, very low prio; please avoid this situation by using wires instead of directly connect 3 or more terminals. Thanks to Erich, whose report on gschem import led to this feature. Best regards, Igor2
Reply subtree:
5972 [pcb-rnd] sch-rnd new: direct terminal-terminal connections from rn...@igor2.repo.hu
5975 Re: [pcb-rnd] sch-rnd new: direct terminal-terminal connections from Bdale Garbee <bd...@gag.com>