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[PIC] PIC18F4550 - how to add to Eagle PCB designer software?

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Hi,

Now the GND connection of USB, PIC, bulk capacitor and step up circuit is far better..

Klaus
 
Thanks!

I have added LEDs (status and power), reset button, 10k on MCLR and 100nF at power lines.
I've tried rebuilding project from scratch but I can't get any betterr...
k2.png

I don't know what abou the step up tracks, but I can't get them better (nor by hand and neither with autorouter).
Well, but this circuit worked on drillboard (the one with holes where you just solder components) so I can only hope....
Also I will make sure there are no overlaps, but I don't know what then.... I will be making my PCB soon

ah and the type of capacitor I will change soon.... but I won't add more components, I think
 

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Thanks, I have followed your hints and made this:
finally.png
I have two more questions:
1. are there any track improvments I can make now?
2. Can the tracks have larger width? It makes easier to make PCB.... now they are 18 mil I think... I've tried with 25mil but then autorouter was failing
 

Hi,

sorry, i thought the EAGLE files are attached. I don´t have them available now. Maybe in 6 hours....

Many years ago i etched may boards too. 18 mils should be OK, but if you make them thicker it is no problem.

***
I saw you routed all the GND lines. This is not necessary .. more a waste of time with the use of the GND polygon.

Autorouter.
The autorouter can only be as good as the informations you give...
Here the autorouter doesn´t know about curents and pulses and what device is for VCC decoupling. It doesn´t know about placement of components...
--> so it simply routes all signals for connections. But you could give a lot of informations to the EAGLE autorouter to get better results.

I professionally route industrial layouts for many years now, (the biggest was about 40 x 50 cm with 16 layers and about 40.000 drill holes) and only for a couple of uncritical signals I use the autorouter.

***

Instead of using the autorouter I recommend to use some tutorials on how to recognize possible problems with the layout.

****
Further improvements...
* Another person will surely do some routings different .... there will be no perfect layout.

* maybe placing the USB connector to the edge, to avoid problems to insert the plug.
* Again, I strongly recommend to use some additional capacitors. At supply and ADC. Read above and my PDFs.

.. but the biggest problems are canceled...

Good luck

Klaus
 
Well sir, I have changed the width of the most of the tracks to 0.032 (is this big?) and clearance of rastnet to 20 mil, and now PCB looks like this:

almostReady.png
Most likely I will be etching it tonight, can you do the final review and tell me if those width changes have any disadvantages?

PS I will also try to add the extra capacitors mentioned by you, but I'm no sure, the pin 5 for example is digital in my case, i am not using vref feature...
 

Hi,

R14 should be about 10k .. or are the 500R correct?

The wires to R7 is thick. Don´t you expect problems when you passing the IC pins?

The same is with the power supply (+5V_USB) line at X1.

Did you do you the DRC setup for "clearance"? Does the DRC run without errors?

Klaus
 
R14 should be about 10k .. or are the 500R correct?

copy&paste bug, it's obviously 10k

The wires to R7 is thick. Don´t you expect problems when you passing the IC pins?
I am going to cut of those pins of IC socket because I won't use them, so I dont think it's a problem, but idk....


Did you do you the DRC setup for "clearance"? Does the DRC run without errors?
It shows 47 errors but I've increased the clearance after designing the tracks but before doing ratsnet, so it might be wrong?
 

Hi,

AFAIK ratsnest changes nothing, it is just for visualization. No influence on DRC...


Klaus
 
Hi,

AFAIK ratsnest changes nothing, it is just for visualization. No influence on DRC...


Klaus


Well, but I made this PCB first, THEN I changed clearance value, which essentialy made all of tracks "invalid" because they were made with lower clearance.... am I right?
 

Hi,

Changing the "clearance" in the DRC is for the whole board, for tthe manufacturing process.

You could change the "isolate" parameter at polygons...
Or you can change parameters of net classes for increased isolation...For high voltage signals for example...

..But "ratsnest" doesn't change anything but the view..

Klaus
 

Isn't it the same parameter? I mean, the distance between tracks?

Btw: I see that somebody made his own PCB for similiar project in such a way:
aaa.png
it's very nice, isn' it? Do you think it's possible and worth to redesign my PCB so it looks like this?
He also has 4 transistorrs etc
 

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