I was wondering if there was any kind and generous soul out there that could give me some design review/feedback/criticism on the schematic for my new project. I am trying to stuff a atmega328 (programmed with the Arduino environment), the Adafruit Wave shield circuit and a 10x6 matrix LED driver into a single PCB. I'm looking for bugs, readability, Eagle tips, what have you. My goals are:
- To make it fit into a confied shape (I have 4" diameter circle to work in, so I think I'm in good shape)
- Send it out to a pcb prototyping house (never done this before)
- Use all SMT parts (I've not done much of this before, other than soldering parts on proto boards, but I have a hot air soldering iron on order)
- Get it all done by the end of August.
Anyway, I've ordered the parts and finished the schematic and am playing with laying out the board. I toyed with the idea of eliminating the 75AHC125 buffer and going to 3.3V on the MPU and everywhere else I could, but the deadline is approaching - I was hoping to use the already debugged circuits from the wave shield and the led matrix I built on my bread board.
* The Eagle design check flags the op-amp circuit as having 2 outputs on the same net. The - outputs of the both op amps feeds into the - input without any kind of component in between. I am not up on op-amps - is this safe to ignore?
Stuff I changed (besides swapping parts for their SMT counterparts)
- used microsd card holder instead of full sized SD/MMC
- added a cap to debounce the reset switch
- added the 74ahc125d chip to the waveshield schematic
- using the USB-TTL-3.3V cable to upload instead of an onboard usb to serial converter.
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