New Project inc USB

Hello All,

I wonder if you can help me. I'm creating a PCB for my project and I want to add USB onto the board not only for power but to Program the ATMEGA328p-AU chip that I want to use. I've chosen the CH340G IC for the USB. I could also use the CP2102 IC as well if needed.

I've done the schematic but I would like some expert eyes to go over it to see if it looks ok. There will be no other power to the board other than powering from USB.

Here is the schematic:

If someone can run their eyes over it and let me konw if it looks OK or if anything needs changing I would be grateful.

Kindest Regards,


Missing a decoupling capacitor on the AVCC supply, I would also add an extra capacitor so both pin 6 & 4 have their own.

Personally, I’d add a heartbeat LED somewhere, both for status/activity monitoring and live debugging if needed.

Using D13 is fine, but make it more formal.

What’s the application ?


It's a virtual cassette player for vintage computers similar to the tzxduino and maxduino.

You can load the images in via SD card and play them into the vintage computer as you would have done all those years ago with a proper cassette recorder.

I've got the D13 LED controlled with a jumper so it can be turned off and on just by shorting the two pins together on the header. This is so that I can test uploading the blink sketch before uploading the main sketch to run everything.



Hi All,

Thanks for all your replies.

I've now added the extra decoupling capacitors. Is there anything else I should be looking at or does everything else look fine?

Thanks Everyone,


If you want to mount an external USB connection to your project, see this USB bezel.
** For transparency, this is a link to my own site. **