Layout tracing Problem

[rishabhbhalla36]

Hi

Currently i am working on my 1st PCB layout I am trying to add traces on a default microcontroller footprint but i won’t be able to add any trace on any pin of the microcontoller i was wondering what could be the problem.

Thanks

Rishab

[1.21Gigawatts]

Have you imported a netlist generated from your schematic?

[rishabhbhalla36]

yeah i did it but it still the same.

[dbrown2k]

How are your rules setup for your trace widths? if the rule there is not enough space Kicad will prevent you from creating a trace.

Check the settings under design rules -> design rules

specifically the minimum clearance.

[rishabhbhalla36]

Thanks that fixed it

[rishabhbhalla36]

can you please check it as well. i have changed the pin name in schematic but when its not changing it in the pcb file. where can i fix this ?

[Rene_Poschl]

You need to import the netlist again to get changes from the schematic into pcb_new.
(Also don’t forget to export it first.)

[rishabhbhalla36]

Thanks

[rishabhbhalla36]

hi

here I tried autorouting but some connections are still unconnected. how can i connect them ?

[Rene_Poschl]

Now you have learned that layouting is hard to do for the computer. (and for humans as well.)

I fear connecting everything will be a lot of work. (For someone experienced 2 or 3 days. more than one week for someone who has no experience.)

First you will need to play around with the placement of the parts. (Yes this means maybe deleting some or all of the work you have already done.)
Make sure that you have as little crossing ratsnets as possible before you lay down your first track.

When you start laying down traces start with the most important tracks. (High frequency tracks, analog tracks.) This should be kept as short as possible and they should also not switch layers too often.

Also if you use a micro processor and have some freedom in which pin should do what, you can change around some pins to reduce the number of ratsnet crossings further.
The same holds for connectors. If you have freedom over what pin is used for what you can change pins around to make your live easier.

Sometimes it is also usefull to put chips with a high pincount at an angle of 45 degrees. This can make the fanout easier. (But make sure your manufacturer can handle this.)

If you hit another roadblock rethink your component placement again. (It will take you a few iterations until you are happy.)

Also if you can, use more layers. (4 layers could be a good start. The outer 2 layers for signals the inner layers for ground and positive supply)

Also next time you post a screenshot show us the layer tab so that we now what color is what layer.

In short there is now fast solution to your problem.

[Joan_Sparky]

Read this thread from top to bottom and contact @arvimg, you two might be able to exchange some thoughts and concepts as he went through this recently…

Rat's Nest won't go even after routing

Even after manual routing the rat’s nest won’t go between few pads. And when I went for auto routing , it didn’t route those specific pads. Hence it is showing under unconnected section. What could be done?

[rishabhbhalla36]

Hi,
I tried a little, I managed to get all connections is there anything else should I need to look for ?
And for the both of the layers top and Bottom I put them both on ground potential with the filled zones. would that be ok or should i change it to something else ?

[rishabhbhalla36]

Hello

Is it possible if I can use the same schematic and footprints to make another layout. If yes how can i do it without affecting the older PCB layout? waiting for reply

Thanks

[Rene_Poschl]

Just copy your project directory.
(this is the directory that holds your .pro, .pcb_new, .sch,… files)
I do this all the time. My project folders are then normally named something like “project_name_Vx.y”.

This thread from today might also be informative to you:

How to start over in Pcbnew

I am working on my first PCB and I have started over 3 times now. Every time I create a new project because I cannot find the ‘reset’ button for Pcbnew nor can I find a way to create 2 Pcb’s based on the same schema, the button ‘new’ is just missing from the File menu. What is the best way to generate a new/clean PCB after I made a lot of changes to the schema? Included this picture of my current schema so you have something to laugh about [image]

[rishabhbhalla36]

Thanks
but it doesn’t open up the schematic but just the layout. Is it that how it is?

[rishabhbhalla36]

Hi,

What is this symbol for this is irritating me How can i remove this ?

[John_Pateman]

Do not dry clean …

[Rene_Poschl]

@rishabhbhalla36

What is this symbol for this is irritating me How can i remove this ?

It is either the grid origin or the auxilary axis.
You can “delete” them by setting them to 0,0
(Left top corner of the sheet.)
These two buttons set the origins. (click the image to see the full screenshot.)

[Ralph_Loveday]

I never auto route small boards. Humans (+ perhaps monkeys==shakespeare) can do a better job.
On 2 layer boards, I try to keep the bottom layer for ground connections.
And am careful to keep IC supply bypass capacitors close to their owners.
Then I try to route, minimising vias. (Every through hole is a possible point of failure).
Lastly, i try to shorten & thicken voltage supply tracks.
Im sure other contributors have a similar process.

[rishabhbhalla36]

yeah i had to start it over hoping to do it better this time