Please critique my design!

Hello everyone, I’m currently working on a USB circuit to use on all my USB boards. I used the Arduino Leonardo as a basis for this design, as well as the Arduino Micro and Teensy 2.0. It uses the atmega32u4. Mainly i’m concerned about making the board rock solid against noise, usb dropout, etc. Please have a look and let me know what you think. Thanks in advance!

http://www.gbmidi.ca/wp-content/uploads … ematic.jpg

http://www.gbmidi.ca/wp-content/uploads … _Board.jpg

Also, I guess the scaling of the images didn’t work. If you right click and save the image to desktop you can see the whole image.

The first thing is you don’t need an image host to post images here. Just attach them to the post. Their is an “Attachment” tab under the text box.

Second, there are nets in your schematic that have no identification. Like the Vcc on the Atmega. Eagle does have symbols for the supply…

Use the smash command or button to organize the lettering. You don’t need the values on the board. Some of the lettering is too small, they need to be at least 0.032" in size.

The USB connector is not correct. If you try to push in a USB cable, it will just hit the board. The white lines should be off the edge of the board.

You need to run an ERC check on the schematic and a DRC check on the board. The DRC check should be have the values from your board’s fab house.

For the setup, I haven’t got that far yet…

teensy thin gnd line for a start.

GND amongst several other tracks Needs making a lot fatter, especially where leaving a PTH pad.

if R1\C4 are on the bottom why not put more there & reduce track lengths, or move them back onto the top as double sided assembly is more involved.

Circuit wise, ISTR that a 0.1uf would go with C1.