Topics

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

freefuel@...
 

Hi all, 

I'm having trouble getting the CP2102 chip on my Radunio to be recognized by my Mac Mini, however the Arduino IDE program can see my other Arduino boards and my FTDI based USB to Serial adapters just fine, I want to know if I can use jumper leads to connect to the NANO without damaging any of the chips. 

-Justin N2TOH 

Tom, wb6b
 

You should be able to connect your FTDI cable directly to the D0 and D1 pins on the Nano. The onboard chip drives the serial data through 1K resistors and allows the D0 and D1 pins to override the onboard chip. You may need to manually press the reset button before starting a new program upload. 

Tom, wb6b
 

One more comment. I was assuming your cable is intended for 5 volt digital logic connections, not actual RS-232. If it is RS-232 then the voltages may be an issue. But, you may be able to use limiting resistors and diodes to protect the Nano, you will need to experiment.

freefuel@...
 

the FTDI interface board has selectable 5 or 3.3 volt TTL logic levels, along with lead for the reset pin. it's intended for Arduino boards that do not have the Serial interface chip. 

-Justin N2TOH

Nick VK4PP
 

I was wondering something similar, to remove the USB section of the Arduino Nano to clean up any birdies caused by it.. thoughts?

Nick VK4PLN

Jerry Gaffke
 

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?

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?