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Re: cvpcb fileformats and BOM enhancement proposal
Sun, 13 Apr 2008 10:02:57 -0000
--- In kicad-devel@xxxxxxxxxxxxxxx, Dick Hollenbeck <dick@...> wrote:
> > cvpcb has a GUI and is focused on footprint assignments. Reference
> > designators and footprints need to be assigned in the schematic editor
> > then show up in the netlist. I would propose that instead of having
> > cvpcb produce an updated netlist, it update the schematic file
> > This would eliminate the need to write a back annotation tool to
> > update the schematic for board turnon or manufacturing reference.
> > There already is a placeholder (F2) of the component for the foot
> > print in the sch file and the footprint currently can be assigned in
> > EEschema by editing each component instance and it will show up in
> > the netlist. It also would be handy while creating a schematic to
> > include the footprint in the add component cache along side the name.
> Seems like a reasonable idea. I see no problems with it, but I not an
> eeschema or cvpcb expert.
> > Adding a vendor part number (VPN) field (F3?) would enable an improved
> > BOM listing. This field would be optional and would show up in the
> > BOM if present. The advantage of a VPN nails down a symbol and
> > footprint. Selection of a VPN defines a specific footprint while the
> > schematic symbol could look like anything the schematic designer likes
> > as long as the pinout is consistant. A VPN enables future creation of
> > a project (or board) only BOM (or library) and could reference a
> > larger company wide parts library (or database). Without this each
> > designer potentially re-invents a symbol/footprint library for each
> > project.
> The fields are present already. I did exactly this on my last
> project. I added a Vendor field, and a Manufacturer field. In the
> Vendor field you would see something like "Digikey 12345" and in the
> Manufacturer field you would see something like: "AMP 1234".
> (Then I wrote a java program to extract the BOM from the *.sch file and
> put it out to CSV format, where after it was loaded into a
> spreadsheet. This is a very slick bom, it even collates like
> components for a second table, and then lists all ref designators in a
> common cell. So you have a single component table, and a collated
> both, that way you know how many you need to order from the collated
> Without picking field names, I mean hard coding them, we could
> "project specific" set of field names, and save these desired field
> names in a config file. That way they would show up each time the
> Component" popup came up. Again, without actually being hard coded.
> > Example:
> > part # symbol sect footprint ref manufacture description
> > --------- ------ -- -------- --- ----------- -----------
> > DM74LS00N 7400 A DIP14 (or N14A) U1
> > DM74LS00M 7400 B SMP14 (or M14A0 U2
> > 54LS00W 7400 A W14B (or CFP14) U3
> > Note: this is 3 separate parts and need separate ref designators
> > (Using similiar but different parts can happen)
> > Parts with multiple sections only count as one part in the BOM with
> > a shared footprint, the section letter would not be listed. The
> > manufacture, description, inventory could be added to a future,
> > separate parts database, selector, navigator....
> > The bottom line is the schematic should be the master controlling
> > document...need to swap parts, pins or change footprint? - update
> > the schematic and re-generate the netlist.
> > A more complicated parametric example:
> > Digi-Key Part Number FC0603-50BFTR-ND
> > Manufacturer Part Number FC0603E50R0BTBST1
> > Symbol: R
> > Description RES 50 OHM 125MW .1% 0603 SMD
> > Manufacturer Vishay/Thin FIlm
> > Resistance In Ohms 50.0
> > Power (Watts) 0.125W
> > Tolerance 1/8W Â±0.1%
> > Lead Style Surface Mount (SMD - SMT)
> > Case 0603 (1608 metric)
> > Packaging Tape & Reel (TR)
> > Composition Thin Film
> > Voltage - Working *
> > Temperature Coefficient *
> > Quantity Available 1
> > Minimum Quantity 1
> > Unit Price USD 0.91000
> > Datasheets
> > here there are many resistors with a common shared symbol and
> I am lost now. You should say where this information is more clearly
> in your proposal. The name of the file, where it is, etc. When
> read in, how it is read in, etc.
> > As a designer why do I want to deal with all this?
> > Ans: To make sure the correct parts are ordered, your board is
> > built right, it will work properly and save the company money
> > by ordering common parts in quantity from a qualified vendor.
> > Frank Bennett
It seems that this thread is posted on both users and devel groups!