I’m starting to use Kicad and when I am editing a footprint I don’t seem to have a pad centre to which I would like to magnetically be attracted to in order to draw a line.
Is there a way to show a pad centre clearly on the screen ?
I’m using v6 of Kicad in March 2022.
(I do note that when I select the measuring ruler a pad centre does appear when I go near it with the mouse … but the magnetism is pretty weak. I need to be very close to the pad centre for it to work.)
Use as coarse a grid as possible to set pads. eg If pads are 2mm between centres use a 2mm grid.
Place pad 1, place point of origin in the centre of that pad and maybe place the grid origin there also, then place all your other pads. (origin icons are just above the ruler icon on the RHS).
When all the pads are correctly spaced then change your grid for drawing lines etc.
It is often easier to place new pads than move old ones around.
I support the answer from @jmk to use a coarse grid and set a grid-point at the center of the pad. So the new line will snap the grid == snap to pad-center.
You could set the “grid origin point” prior to this operation, this will definitely place a grid-point at the pad-center to help with snapping.
Don’t forget to reset the “grid origin point” after all changes are done.
Another variant, maybe helpful:
snapping to center of pad works if you draw a line on the pad-layer (== F.copper). So you could draw your lines/graphics first on F.copper and than convert the layers to F.silkscreen/F.Fab/whatever. (sadly Edit–>Edit Text&Graphics Properties to bulk-change all layers at once works not in Footprint-editor of v6.0, only in v6.99)
Also forget:
you have to set the Preferences–>PCB-Editor–>Editing-Options–>Magnetic Points–>Snap to Pads probably to “ALWAYS”
Thanks for the replies.
I have the magnetic option ticked but I am working in the Footprint Editor not the PCB Editor. There doesn’t seem to be an option for ‘always’. (v 6.02)
“Grid origin point” and "“Point of Origin” are going to have me confused.
Should I develop my component library to origin to pin 1 on all devices ? Sometimes devices are designed or referenced to pins or mounting points other than pin 1.
Should the reference point of a component footprint match the reference point for the schematic part also ? ie. they both reference to pin 1 ?
Rgds,
I have the magnetic option ticked but I am working in the Footprint Editor not the PCB Editor. There doesn’t seem to be an option for ‘always’. (v 6.02)
You are right, there is no extra “magnetic point / snapping option” for FP-editor. Seems snapping to pads in FP-editor is always on for layers which belong to the pad (top copper for smd / top+bottom for THT) and no snapping for all other layers.
“Grid origin point” and “Point of Origin” are going to have me confused.
Confusion is the first step to understanding.
Grid origin point (the icon on my picture above, also available in FP-editor) is only for drawing and is “forgotten” after closing the FP-editor. This sets the start-point for the grid, example:
Point of origin - I think this means the footprint anchor point. Is normally located at 0,0-coordinate. See below for remarks.
Should I develop my component library to origin to pin 1 on all devices ? Sometimes devices are designed or referenced to pins or mounting points other than pin 1.
You decide for yourself, there is right/false. The only important advice: Be consistent, so choose a system and build all footprints according to this decision.
As an example the Kicad library convention (KLC, https://klc.kicad.org/, section F6.2/F7.2) writes:
I personally follow the rule for SMD-footprints, but have an other opinion regarding THT-footprints.
Should the reference point of a component footprint match the reference point for the schematic part also ? ie. they both reference to pin 1 ?
No.
for symbol: set anchor-point always into the middle of the symbol.
for footprint: see above. And special footprints (irregular shaped sensors, special connectors, other edge cases) will require divergence from standard footprint-anchor-point settings.
Thank you for the reply.
I think in my past I have located the schematic symbol to a pin and generally pin 1 and usually locate the origin of a footprint to pin 1 also. I am also now making schematic symbols that represent the actual hardware. A bit like their footprint. This is so I can represent desired component placing on the schematic. So for example, if the decoupling capacitors are to be placed near a pin then I show it in the schematics. It also allows me to visualise the pcb design to some extent.
I guess if the program can ‘get over it’ it won’t matter much.
I am careful to make schematic parts that are pin-spaced such that the grid is fairly coarse. There is not usually so much choice with pcb footprints.
I guess if the program can ‘get over it’ it won’t matter much.
Kicad can live with “symbol anchor at symbol pin1”. It’s unusual (I have seen some schematics/symbols drawn this way, but not much) but I see you have advisedly made that decision.
My other point from above remains: try to be consistent, so try not to mix different “anchor”-strategies.
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