Custom Arduino Mega 2560 - USB Communication

Hi all,

I have created a customised Arduino Mega board for a project I am working on. I have built it off the work done by FuzzyStudio https://www.instructables.com/id/DIY-Bare-Minimum-Arduino-Mega-2560/.

The board incorporates a CP2102 module with USB C [2.0] connector for communication after burning bootloader. Eagle Files attached also.

I have successfully loaded the bootloader [via a Uno as a programmer] with both the inbuilt bootloader and Nick Gammon's sketch. I have also run the 'Sketch to detect Atmega chip types' from him as well. Results attached.

The have installed the latest drivers from Silabs on both OSX & Win10. Both of which seem to recognise it when plugged in. I have tried two different USB cables as well.

However, I cannot seem to be able to load sketches directly via USB. I get the following errors:

avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

Is there a something I am missing? I gather there may be an solution involving adding a capacitor to the reset pin in some arrangement. But I would like to know if there is a problem with the overall design before chasing that solution.

Any input is appreciated...

Atmega_Board_Detector_Results.txt (46.6 KB)

motorcycleDisplayController.zip (111 KB)