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Re: can I bypass the CP2102 chip on the NANO with an FTDI based serial adapter? #nano #arduino #cp2102 #ftdi

Clark Martin
 

You could try forcing the USB chip into the reset state by holding the reset\ line low (FT232RL - pin 19, CP2102 - pin 9).  Test it out by connecting a 100 ohm resistor from ground to the reset pin.  The resistor should pull down any pull up resistor but not short out the supply if Vcc is tied directly to the pin.  it shouldn’t hurt anything to try this but it might keep something from working.

Doing this MAY turn off the clock.  It should certainly reduce noise induced on the power supply lines.

If it does work you could add a jumper so you could still use the serial port when needed.

Clark Martin
KK6ISP

On May 13, 2018, at 6:38 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Should work fine.
Note that the Nano has an FT232RL USB-to-serial chip that includes a 5v to 3.3v regulator. 
This currently powers the si5351 through the Nano's J2 pin 14.  On the clones, it's CH340 chip.
    https://www.arduino.cc/en/uploads/Main/Arduino_Nano-Rev3.2-SCH.pdf

You will need to replace that regulator with something else if you remove our CH340 chip.
This new 3.3v regulator could be mounted on the Raduino board.

Jerry


On Sun, May 13, 2018 at 06:21 pm, Nick VK4PLN wrote:
I was wondering something similar, to remove the USB section of the Arduino Nano to clean up any birdies caused by it.. thoughts?
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