Making symbols in Eagle! - Page 1
Forum section: electronics / general

author: Sudo_apt-get_install_yum
author_rank: Regular Contributor
timestamp: November 06, 2018, 09:33:23 am
content: Hi all!So I design my circuit boards in Eagle 9xx and it’s a pain in the A$$ to make symbols, making the footprint is usually not a big problem unless it’s an odd shape/polygon like an anchor point of a ziff socket. But when it comes to making a symbol I have to draw the symbol by hand in the program and it’s just a real hassle.What made me make this post is a standard n-channel mosfet (2N7002KW), it has a SOT323 package and it take a minute or two to make the footprint but it takes forever to draw the mosfet symbol!Does anybody have a suggestion to an easier alternative to drawing these by hand, once I draw these I can copy them but it’s a pain to draw symbols in eagleAnd don’t make me get started on the package generator in eagle!

author: rachaelp
author_rank: Unknown
timestamp: November 06, 2018, 10:26:52 am
content: Quote from: Sudo_apt-get_install_yum on November 06, 2018, 09:33:23 amCan you elaborate a little more what is taking up your time when doing the symbol? It's not a large symbol and only has 3 pins and last time I drew one it only took a few minutes. I guess it might be drawing the details like arrows, body diode, etc? The ALT grid will probably be helpful here so you can have your main 0.1" grid to place the pins etc on and then use the ALT grid to give finer resolution for the detail.Re the package generator, yes it's not without its issues, it's getting better though and it's usable now.Best Regards,Rachael

author: Sudo_apt-get_install_yum
author_rank: Regular Contributor
timestamp: November 06, 2018, 12:28:23 pm
content: Quote from: rachaelp on November 06, 2018, 10:26:52 amThis was just a specific thing that came up when doing a larger design, making a single mosfet doesn’t take more than a few minutes.It’s the way that the "drawing system" works that really bugs me, when doing symbols, outlines or polygons and any other thing that has a specific length in eagle it becomes a real pain since you can input dimensions only beginning and end of the lines/shapes. And when a datasheet has an oddly shaped pad and the measurements are defined from the edge of another pad, then you have to convert it into coordinates. It’s not hard in any way it’s just that it gets really tedious when making detailed things...Maybe I’m just spoiled from doing a fair bit of work in solid works

author: montemcguire
author_rank: Regular Contributor
timestamp: December 02, 2018, 02:42:54 pm
content: It sounds like you're not using a grid setting that makes sense. For symbols, you generally do everything on a 0.1" grid, and only for some fine details will I switch to a finer grid setting to draw things like the arrow of a bipolar transistor emitter. Even then, how many times do you have to draw that emitter arrow? Once - do it once and copy it. Then, that arrow is exactly the same everywhere and things look better.For the package, the grid can help out a lot here as well. If you get one pad set to the right dimensions and your part uses for example, multiple pads on a 0.65 mm lead pitch, you can set the grid to 0.65 mm and then duplicate the pad and drag each pad out to the rest of the locations. Grouping objects can also be helpful too.Finally, there are some things that the editor is very clumsy with, but the libraries are in a text XML format, and you can edit them directly using your preferred text editor. Sometimes I will do this to do a global search and replace to set a feature from one size to another without having to tediously select and enter the new dimensions.I think most CAD programs are annoying in some way or another, and they're all different somehow, but the Eagle editor is definitely good enough to get things done, and if all else fails, you can edit the XML directly. Best of luck!