Hi Reece, Have a look at an earlier message regarding bus upgrades [1].
Cheers, Orson 1. https://lists.launchpad.net/kicad-developers/msg32423.html On 04/20/2018 05:15 PM, Reece R. Pollack wrote: > Let's not forget the pending wishlist item Bug #1419146 > <https://bugs.launchpad.net/kicad/+bug/1419146> to support buses of > named members. > > You shouldn't have to remember that I2C_DATA is better known as I2C_0 > and I2C_CLOCK is I2C_1. Or was I2C_CLOCK = I2C_0 and I2C_DATA = I2C_1? > > Extending this idea so a bus can contain another bus makes sense. Let's > take an LCD display. In addition to the 4 or 8 data lines, there are > several control lines that should be part of the bus. I want an LCD bus > that contains LCD_E, LCD_RS, and LCD_RW as well as LCD_D[0..7]. And > while I'm fantasizing, I want the bus name to be "LCD"; I do NOT want it > named "LCD_E,LCD_RS,LCD_RW,LCD_D[0..7]" the way it is in Eagle. > > -Reece > > On 04/15/18 22:39, Seth Hillbrand wrote: >> Hi Jon- >> >> The major issue I think we would need to address is migration. I >> don't think that only an ERC warning is sufficient in this case. >> Users will rightfully expect that their old schematics will generate >> valid netlists when opened in a newer KiCad. >> >> One option here would be to translate the implicit net connections >> into explicit ones when bus junctions are encountered. Unfortunately, >> I think that this feature is lightly used, so we might not get much >> user feedback until they encounter problems and then the problems will >> be very bad >> >> An alternative might be to increase the functionality of the bus >> junction. Spitballing here but we might add a "mapping table" dialog >> that allowed the user to specify the winning name and mapping order. >> That should address your points 2-3 although point 4 might be the >> issue. I think we could have a default mapping that follows the >> expected convention but allow users to change it by double-clicking on >> the junction and editing the mapping table. Then previous users could >> keep their functionality while still allowing the arbitrary member >> arrays you are building. >> >> Thoughts? >> -S >> >> >> 2018-04-15 16:40 GMT-07:00 Jon Evans <j...@craftyjon.com >> <mailto:j...@craftyjon.com>>: >> >> Hi all, >> >> I am proposing to remove some behavior from KiCad as part of my >> bus connections changes. I know we generally don't remove >> features in new releases without good reason, but I think this is >> an exceptional case. >> >> The user manual describes a way in which you can connect multiple >> different buses together with junctions. If you aren't already >> familiar with this behavior, please check out the manual: >> >> http://docs.kicad-pcb.org/stable/en/eeschema.html#wires-buses-labels-power-ports >> >> >> <http://docs.kicad-pcb.org/stable/en/eeschema.html#wires-buses-labels-power-ports> >> >> >> The section in question is called "Global connections between >> buses" and comes with the following image and describes how these >> bus wires with different labels are connected together: >> >> Allowing this kind of behavior is problematic for a number of >> reasons: >> >> 1. It means that net wires and bus wires behave differently, since >> net wires can't have more than one label. This is potentially >> confusing for users. >> >> 2. It means that junctions need a lot of special logic in order to >> resolve which "branch" of a bus is called what name (for example, >> what if one of those three branches in the above image didn't have >> a label? What would its nets be called?) >> >> 3. Maybe most importantly, it breaks the label->netlist paradigm, >> since an electrical net will only have one label in the eventual >> netlist, and there is no way to determine which label should "win" >> >> 4. I don't think there's a way to map this behavior onto the new >> bus system I have built that allows arbitrary bus members (instead >> of just a sequential vector) in a way that would make any sense to >> the user. >> >> My proposed changes in this area are as follows: >> >> 1. Remove this section from the user manual. >> >> 2. In my new connectivity algorithm, treat all connected bus wire >> segments as being part of the same bus (meaning they all will have >> the same "name") >> >> 3. Add an ERC warning about having more than one label attached to >> a bus (the warning would appear in the case of the example picture >> above) >> >> 4. Add a note to the user manual stating that this warning is new >> for 6.0 >> >> The only downside that I can see in this approach is that any >> users who relied on this feature will suddenly get new ERC >> warnings. But I think that this is an "anti-feature" in that it >> creates confusion instead of adding value, so we should nudge >> anyone who uses it towards a different approach. >> >> Anyone see any issues with this plan? >> >> Thanks, >> -Jon >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~kicad-developers >> <https://launchpad.net/%7Ekicad-developers> >> Post to : kicad-developers@lists.launchpad.net >> <mailto:kicad-developers@lists.launchpad.net> >> Unsubscribe : https://launchpad.net/~kicad-developers >> <https://launchpad.net/%7Ekicad-developers> >> More help : https://help.launchpad.net/ListHelp >> <https://help.launchpad.net/ListHelp> >> >> >> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~kicad-developers >> Post to : kicad-developers@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~kicad-developers >> More help : https://help.launchpad.net/ListHelp > > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~kicad-developers > Post to : kicad-developers@lists.launchpad.net > Unsubscribe : https://launchpad.net/~kicad-developers > More help : https://help.launchpad.net/ListHelp >
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