Re: Real or Clone - Nano survivability, any real difference?

Jerry Gaffke

The host computer needs to know how to talk to the USB-to-UART chip on the Nano.
This chip converts USB traffic from your host computer (perhaps during a firmware download)
into UART transmit and receive wires for the ATMega328P processor chip.
The two wire UART interface is a standard that's been around for 50 years, and much simpler than USB.
A number of issues here:

The original Arduino Nano uses an FTDI chip for that USB interface, a MicroSoft Windows (MsWin) host computer
will require the download of a software driver from FTDI so it knows how to talk to that chip.
The FTDI chip was wildly successful, and some overseas manufacturers started selling cheap clones of the chip.
FTDI responded by adjusting their driver to detect these clones, and can brick devices using a counterfeit chip.
Something to be aware of when buying really cheap boards that claim to have an FTDI USB-to-UART chip.

The FTDI chip costs four or five bucks, to sell a complete Nano clone at $2 on ebay they need to use some other chip.
Most of them use the CH340 chip, which is what the Nano clones from hfsignals are using.
The CH340 chip requires a different software driver to be downloaded and installed if using MsWin.

Another popular USB-to-UART chip is the SiLabs CP2102, some Nano clones use this chip.
Again, requires a different software driver to be downloaded if using MsWin.

I'm running my Arduino software for Nano program development and firmware downloads under Ubuntu linux.
Everything pretty much just works, all the drivers are included in the default Ubuntu package (must configure permissions).
You can also run the Arduino software under linux on a $30 RaspberryPi3 if having trouble with your regular computer.

Some in the forum are running the Arduino software under MacOS.
Possible, but can be very tough to get MacOS to talk to some of these USB-to-UART chips.

When no host computer is plugged into the USB port on the Nano, the USB-to-UART chip is sleeping.
It is possible to drive the UART TX and RX lines on the Nano from some other off-board USB-to-UART chip.
This might be handy if you have trouble with talking to a CH340 chip on your Nano from MacOS, for example.

The Arduino organization has kindly made their software and the design for these boards open source.
So Nano clones are legit, though they are successful largely through the hard work of the Arduino guys.
As Jack suggests, it's good for all of us to help Arduino pay the bills when we can.

The bootloader issue that Jack points out is not something I've encountered, 
but good to be aware of.

Jerry, KE7ER

On Thu, Apr 4, 2019 at 08:04 PM, Jack Purdum wrote:
I've been pretty lucky with the clones. The biggest problem I've had is the non-standard drivers. However, in most cases, downloading/installing the CH340 device driver fixes that problem. More recently, I thought I was seeing the driver problem again, but even installing the CH340 didn't fix it. Turns out some of the clone manufacturers are using an ancient bootloader that is confused by the recent versions of the IDE. Fortunately, it's easily solved. Use the menu sequence Tools --> Processor: "ATmega328p" --> ATmega328P (Old Bootloader) and do another compile/upload sequence and that should take care of it.

Join to automatically receive all group messages.