Hacker News new | ask | show | jobs
by mindentropy 1106 days ago
How do you go about doing the mechanical drawing for a footprint not found in the library? I tried to design a simple SD card board as a learning project. I gave up when the part that I selected was difficult to draw. I was not sure whether I was missing some information or is it my inexperience. My persistence on learning and eventual failure left me with the bad taste.

PS: The part I selected seemed to be a generic brand and did not get any info to clarify the dimensions.
1 comments
neltnerb 1106 days ago
There is a footprint wizard, like EagleCAD had. That's usually where to start if it's at all possible.

I personally don't think I'm good enough at KiCAD to draw one from scratch. I could probably make it okay, but it wouldn't be professional quality. Life goal is to be able to meaningfully contribute to the project library globally, they have high standards.

I managed to draw a USB port that was probably the trickiest one I had to do. It was really the same as eagle, I had to place pads, give them proper numbers, define through holes (it let me do slots, even with an offset which was way better than Eagle), and then it just let me connect it to a USB-C symbol in my schematic no questions asked.

But making a custom symbol was also the same as Eagle. Same process, label pins, define directions, place labels...

The only difference maybe is that footprints and symbols aren't forcibly associated, and connections are done via the pin/pad numbers.

With a datasheet of that low of quality you're better off measuring by hand though, I don't know a way around that one.

link
mindentropy 1094 days ago
The biggest problem for me in doing custom symbols is the measurements and the subsequent drawing. My life goal is as yours, manage to create a custom symbol and also build my own custom dev board. Unfortunately many things got in the way and the work kept delaying for almost 9-10 years now.

The reason I picked a particular SD card was because it was low cost. My country has crazy import fees and because of this I am forced to select low cost parts which usually have bad datasheet and documentation.

link