I'm moving my Uno tested 328P design to a stand alone PCB. Since this is my first attempt I thought it would be prudent to request a review.
I've included ICSP and FTDI headers to allow bootloader and sketch uploading to a TQFN package. If I do this I'll replace the pins with POGO style pads.
All constructive feedback or suggestions to improve the design are welcome.
Thanks
Two 0.1µF capacitors. One between VCC and GND as close as possible to the processor. One between AVCC and AGND as close as possible to the processor.
RESET is not labeled on the processor.
Why not use internal pull up on s1?
The FTDI header lacks SIGNAL NAMES
If this is a PCB, where's the header for interfacing I/O ?
You have a signal named 'PD3' connected to pin2 (PD1) of the microcontroller. That sounds like a recipe for disaster.
You have a signal named 'PD3' connected to pin2 (PD1) of the microcontroller. That sounds like a recipe for disaster.
I was wondering about that too. I have no idea why he chose those names for the FTDI pins.
It really doesn't make any sense , does it ? He needs to change the names on the FTDI header to function names. I don't know how someone can be making a uP PCB and not know how to name the pins on the header.
DTR from FTDI pin is miswired - should be a 0.1uC cap to reset pin. Look at how Promini is connected and make it the same.
Add a diode across R18, cathode to +5, to prevent reset spikes from fooling chip into going into High Voltage (12V) programming mode and appearing to be hung after the reset switch is used.
Label Pin 1 reset so it gets connected.
Hard to say about the rest without seeing the rest of the schematic.
Thanks for the input. It's 0330 and I'm off to work so I'll address all comments later today.Sorry about the net labeling, I changed out the package just before I decided to post and didn't notice I had the pin names still on them. The package in Eagle doesn't have the proper labels. I'll fix that up.
