Hi all,
[Please forgive me for any errors, but this is my first post to this forum]
A month ago I designed a USB RF board that would use the Atmega16u2 MCU and an RF IC. It was meant to communicate with the pc over usb (emulating a Serial COM port - just like the arduino does). I built the schematic and later the PCB drawing and ordered a couple of prototypes.
Now, I am struggling to get the USB working.
As for the Software, I am using the arduino’s firmware for the atmega16u2 on the UNO R3. (Since I just want to test that my device is detected by the PC, it should show up as Arduino UNO in the device manager)
Fuses are: lfuse: FF, hfuse: D9, efuse: F4 or FF (tested both)
As for the Hardware, I have a few concerns about the diagram. The device has a 3.3v linear regulator powered by the USB’s 5v line. (This gives power to every IC on the board). I first intended to use a 16Mhz crystal for the atmega16u2, but later found that I should use a 8Mhz for 3.3v operation. (For now though, I am stuck with the 16Mhz one - but it still runs (blinks leds, communicates with USART etc.)) The firmware is also built with F_CPU=16000000.
So, trying to sort out the problem I first have to make sure the schematic is correct. Here is a part of it:
http://airdevs.com/Schematic.png
Are the connections OK ?
Thanks in advance !