First Eagle Schematic/ PCB

[Jay]

Hello, hopefully this is the correct place for this! I'm currently learning this whole Eagle schematic and pcb creation workflow. Was hoping for some pointers if possible. I'll attach a pic of my schematic and layout so far. I just placed the parts, I have a feeling they could be better arranged, but I'll consider this my first draft. I'm definitely open to any constructive criticism.

For reference I have been using this guide (not related to pedals at all)

https://learn.sparkfun.com/tutorials/using-eagle-schematic
https://learn.sparkfun.com/tutorials/using-eagle-board-layout

This is the schematic I am practicing with:
http://www.diyguitarpedals.com.au/shop/boms/Classic_Boost_Schematic.pdf

I stopped at Routing the Board in the second link before I started routing things.

My initial questions are:
1. Can anyone point me to pedal specific tutorials in Eagle?
2. What can I best do to optimize my current PCB layout?


Thanks in advance Gents and Ladies

Jay

[HamSandwich]

Hello Jay, couple of comments.

1) your diode, cap and transistor pads look VERY small. The lead may or fit through, and even if it did, it will be very hard to solder to such a small pad.
2) you have a lot of room between components. If this were a board for someone learning to solder, the ample spacing would be great. If you are competent at soldering, I'd move all the components together more. I'd also orient them vertically instead of horizontally, that way you can route traces underneath components instead of around. You'll also save money by not using unnecessary space at the fab house.
3) I don't see any in, out or power connections!

I suggest getting the book PCB for musical effects by RG Keen, who is the mind behind GEOFEX. I also suggest looking at and learning from other people's layouts. Your learn a lot. Finally, read up on ground planes as I think that are invaluable. The book will help you with the layout, and any EAGLE tutorial will help you out with the program, but they are two separate skills to master.

There is an EAGLE section of this forum and you may find many threads there that are helpful. 

[alanp]

http://www.madbeanpedals.com/forum/index.php?topic=25194.0

Strongly recommend Brian's libraries.

[Jay]

Excellent. I have an older version of his library. Lots of errors with the version of eagle I have. I've been updating each file manually. I'm a programmer so it's not too far out of my scope.


Sent from my iPhone using Tapatalk Pro

[Flying]

I started using Eagle just before Christmas, and my list of pedals has grown as a consequence, three overdrives, a compressor, a delay and a vibe! And today I'm been putting the finishing touches to a fuzz face and another overdrive PCB artwork.

I'm etching my own PCBs and if you plan to do the same then some of the default settings might not be the best. For example in the fuzz face example I've attached I use a track width of 28, a pad size of no less that 60, and a drill hole of 19.86, I drill the board with a 0.8mm drill bit for most components, the 19.86 hole size means the drill bit centers in the hole and also drills a little copper when you go through the PCB.

Regarding layout, I'm still learning, and I'm sure I'm making lots of mistakes that might be making my circuits noisier than they should be. One problem is it's a bit addictive, and takes a lot of time, far more than makes sense when you can buy a prefabricated PCB, but it's also rewarding.

[Flying]

Does anyone know if it is possible to prevent Eagle putting pads on both the top and bottom layers of a double sided board? Or ideally, I'd like to design my PCB and then run a script that deletes all the non-connected pads. Sometimes I'll use a resistor leg as a via so it's helpful to have the pads top and bottom when laying out the design.

Last night I printed 'to PDF' the artwork for the next three projects and took the PDF into a vector program and deleted the unused pads, it's not a huge faff, but I feel there should be something in Eagle that will do this for me, and I've just not found it and my searches have not come up with anything either.

Any help would be great.

[m-Kresol]

Does anyone know if it is possible to prevent Eagle putting pads on both the top and bottom layers of a double sided board? Or ideally, I'd like to design my PCB and then run a script that deletes all the non-connected pads. Sometimes I'll use a resistor leg as a via so it's helpful to have the pads top and bottom when laying out the design.

Last night I printed 'to PDF' the artwork for the next three projects and took the PDF into a vector program and deleted the unused pads, it's not a huge faff, but I feel there should be something in Eagle that will do this for me, and I've just not found it and my searches have not come up with anything either.

Any help would be great.

why would you have unconnected pads? if they are not connected, they don't serve a purpose electronically and you should be able to delete them from the schematic/library.

For the fuzz face you posted I don't quite get why you have the vias to connect the pots. with board mounted pots we usually solder them in from the component side, but you should be able to easily solder them from the solder side too

[m-Kresol]

Hi Jay,

some suggestions to your questions:

1) http://www.madbeanpedals.com/forum/index.php?topic=9661.0
Jacob's tutorials are the best. Eagle version is not the current one, but basic function are still identical,

2) try switching places of D1 and C2. Also turn D1 180°. Try to go along your schematic when placing the components (as in place them in a similar way). you have few components and the schematic is really clean (no crossing wires or nets that connect without a drawn wire). For example, C1 and C2 are in parallel, but in your pcb layout they are next to each other rather than placing them above each other. So, if you place C1 on the position of R4 (assuming you also switched D1 and C2), you will have less crossing wires.

3) as mentioned by Flying, component placment is even more important for 1-sided layouts for etching as crossing wires means you have to place a jumper.

4) My tactics for layouts generally is to place pots, switches and in/out/GND/9V and lock their positions. I then work my way from Input to output, usually placing all components before starting the wiring. After that I will shrink the pcb if there is lots of room left and put stuff thighter together. If I want the pcb to be the size I set initially due to the pot placement (e.g. if they would be too close to turn comfortably in the end, or for pure esthetic reasons), I space out the components equally, makes it easier to route traces in between.

hope that helps. have fun!

[Flying]

why would you have unconnected pads? if they are not connected, they don't serve a purpose electronically and you should be able to delete them from the schematic/library.

Eagle puts a pad for each component on both the top and the bottom layers, usually my tracks are on the bottom, leaving pads unconnected on the top, these are my 'unconnected pads'  I'm etching at home so I don't have through hole plating, and when drilling the holes out I get a burr on the exit of the hole which I've spent time removing. So if there is a way I can not have the pads, it woudl be a real help.

For the fuzz face you posted I don't quite get why you have the vias to connect the pots. with board mounted pots we usually solder them in from the component side, but you should be able to easily solder them from the solder side too

This is just habit, my first project had five knobs and a switch I decided it would be safest to solder the pots in from the component side as I could have the pots already installed in the enclosure in advanced. I also decided that if I needed to replace a pot I would potentially do less damage to the pad by pushing the leg through the pad rather than pulling it off the pad. But I'm still learning, I only started this around Christmas.

[m-Kresol]

ah, I get it now... You have a double sided FR4 for etching, but obviously no through hole plating as it is done after drilling in pcb manufacturing.
I don't know of a way to selectively remove some pads on one side only. I think you'll need to continue doing this manually