-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 06/08/2015 11:36 PM, Chris Pavlina wrote: > On Mon, Jun 08, 2015 at 11:28:08PM +0200, Heiko Rosemann wrote: >>> A given component should have exactly ONE available footprint. >>> If your opamp comes in PDIP-8 and SOIC-8, those are two >>> different components. >> >> Why? There's a good point for the opposite: Making different PCBs >> (SMD for series production/no SMD for prototyping/hobbyists or >> different casings) from a single - consistent - schematic. >> Otherwise you are going to run into trouble because you'll have >> multiple schematics of the same system and you need to change >> something on the logical (schematic) side. > > I explained this already. Look at the pinouts for the different > footprints of LT1013. Only a very inexperienced person would claim > that assuming different footprints have the same pinout is a good > idea.
Different footprints for the same component are not required to have the same pinout. You don't have to touch the schematic (there you only see IN1+, IN1-, OUT1 etc. - no information about actual pinout), when you change footprints on the PCB without breaking the connectivity as defined in the schematic. Simplest use case: Transistor in SOT23. Existing variant connects pin B in symbol to pad 1 in footprint, pin C in symbol to pad 2 in footprint, pin E in symbol to pad 3 in footprint. Now you would save a few vias with a different alignment and your transistor is available in reverse, so you create a second variant, connect pin B to pad 3, pin C to pad 2, pin E to pad 1. Don't need to copy symbols, don't need to copy footprints to match pin and pad numbers - and when you route the PCB, you right-click on the footprint and say "change variant", done. In the kicad-model this use case leads to SOT23-123, SOT23-321, SOT23-BCE, SOT23-ECB etc. cluttering the footprint list. It's there already... Again, I'm explaining how Eagle does it (though it doesn't go all the way - if you have different footprints with different pad numbers, like a PDIP40 and a TQFP44, you need to create two components) and where I have actually used it. I'm not saying "that's how kicad needs to do it" (not my place to say this, with no code contributions from myself...), but I do believe the options should be clear. BR, Heiko - -- Mein PGP-Key zur Verifizierung: http://pgp.mit.edu -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAlV2kPIACgkQ/Vb5NagElAWq0gCdETr2IauqQ+IvvQLb9dfAT6M4 FG4AoLOg+ejINxTgLGhTtNZP010IBBOF =rE20 -----END PGP SIGNATURE----- _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
