Arduino Mega Shield in Eagle
Today I created a custom shield for an Arduino Mega project. Through the beauty of open source hardware, I was able to start my project by downloading the blank shield, CAD files for listed on the Arduino Forum. This was a nice experience, the project was not planned, I started this on the fly. I just reacted to circumstances and lo-and-behold, several hours later I was done.
Along the way, my observations regarding the blank shield were as follows: 1) it was created from the Arduino Mega Schematic & Reference Design available on the Arduino web site. 2) On the schematic, the grid didn’t match the parts placement; so wires would not connect to devices. 3) Some of the Mega wiring not necessary for a shield design was still intact. 4) Although my circuit wasn’t all that complex, Eagle couldn’t route all of the signals on a two layer PCB.
My contribution so far: 1) remove useless wiring. 2) Move connectors in the schematic view to the edges. 3) Orient connectors appropriately and get all objects back onto the 0.10” grid. 4) Place connector names in the to the silk screen layer. 5) Move ground plane to bottom side on PCB. 5) On the layout view, add off-board pin identifiers.
I surmise that the original poster (ardui32) had an idea and a motivation to share his work before he had an opportunity to test his work. I appreciate the effort. However it was nice to use his work as a starting point. Ardi32 requested at the end of his post:” If you have better files, post them in this thread.” Before I do that, I’d like to mod the library parts so the pin identifiers match the Arduino pin names. It’s confusing to route signals correctly, as the connector pin numbers are distracting. With this finishing touch, the Arduino Mega Blank Shield would be bitchin’.
Epilogue: After composing this I saw that I have an Arduino library installed in Eagle. I haven’t had time to check, but perhaps a better solution, or even a better idea lies inside.