I have multiple Unos and Nano and recently due to some bad configuration the USBs are not getting recognised on my Mac Air Laptop. These were working models for almost 1-2 years. I used it to control motors and something must have happened and it stopped.

But strangely the small boot up LEDs on the Nano/Uno light up when connected so it seems that the connection from the laptop USB to the device is good - but the driver ports are not showing up on the Arduino IDE. How do I go about resolving that it is not just a software issue and is a hardware issue ?

I reinstalled the CH340G driver.img and yet the device when plugged in - does not show the USB port on the IDE ? Any thoughts or ideas on how to resolve this.

The Uno/Nano are Chinese Clones and have CH340 chipset on them. Is there some firmware that may have gone wrong and can be reset ? or new boot loader that can be burnt to bring them back to life.

I want to be able to see the Tools-> Port -> /dev/cu.usbserial1410 and also be able to see /dev/cu.usbserial on the command xterm prompt .

  • 1
    1-2 years is a good lifetime for a CH340G...
    – Majenko
    May 17, 2018 at 10:42

1 Answer 1


Assuming that the atmega328p still works fine, you can still use the Nano. I have solved this a few times by just using a FTDI breakout board (remember to set it to 5V, though 3V3 upload works on a Nano), and connecting RX to TX, TX to RX. Press reset before each upload.

  • Thanks for the answer - I have a cloned Uno and a Nano. I guess I have to use a different breakout ? My Uno/Nano has a 340G chipset, not FTDI. May 17, 2018 at 14:35
  • 2
    Unos (real or cloned) use a 2nd processor on the board to manage USB communication with your computer. Since that processor or its firmware on your board is not working, @user2497 is suggesting you bypass it with another one on a breakout board or built into a cable. That breakout board or cable will almost certainly use an FTDI chip, regardless of what chip on the clone board has. You'd connect the breakout board or cable directly to the ATmega328p's RX and TX pins, just as its (now non-functional) 2nd processor is.
    – JRobert
    May 17, 2018 at 15:49
  • 1
    I have a PL2303 ( I think it's similar to FTDI) and installed the driver and was able to see the driver on Arduino IDE. PL2303 . Arduino May 18, 2018 at 8:01
  • PL2303 Tx -> Arduino Rx <br/> PL2303 Rx -> Arduino Tx <br/> PL2303 GND -> Arduino GND <br/> May 18, 2018 at 8:02
  • I did not connect the 3V3 of the PL2303 and left if open. What is the Tools-> Board and Tools-> Programmer to use on the IDE ? May 18, 2018 at 8:04

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