I posted this same message in an old thread in the General Section but figured this is probably the correct place.

With some initial help I've made a PCB design that I would like to share with you for feedback. First let me tell you that this is a hobby project for my own learning and amusement. Even though I've tried to follow best practices it is probably far from perfect. For one I know that I could do this with less hardware but I like the experiment and I had a few Teensys at home so I utilize them first. Secondly the bottom half of the PCB is not made by me but by @jerware of Tested.com and unfortunately I could not get ahold of the schematics so this is all done in layout mode (Eagle). My goal was simply to extend the PinSim with another Teensy to handle some LED-stuff and extras. This all works on my breadboard. Now I wonder if I've gotten this right.

The idea is to send a I2C signal to the upper Teensy when a certain button is pressed (callback in software) and then let that unit do some stuff with LEDs. Do I have the Pull-Ups correctly wired? Would this design actually work as I intended? (again the upper half is of most interest in this case and the bottom part is working). Attached image shows the PCB.

The base project is here: https://www.tested.com/tech/gaming/5...nball-machine/
Below is my extended PCB. So again, I'm only worried about the upper half and if the pull-up resistors on the SDA/SCL lines will work as I hope (the I2C bus also hosts a ADXL345. As I wrote earier I have it all working on a breadboard and now I'm in the process of sending this to manufacturing so I just want to make sure I'm not doing anything weird.

Click image for larger version. 

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