Wednesday, September 18, 2013

clone PL-2303HX USB to TTL serial adapters

USB-TTL modules using the PL-2303HX chip are the cheapest ones around ($1.40 from Fasttech).  The chip has a built-in 3.3v regulator, so the modules can supply both 5v and 3.3v power.  Drivers for them are included in the Linux kernel and in Mac OSX too.

Apparently the chip has been cloned, and as a result Prolific updated their Windows drivers to detect the clone chips and fail.  If you are getting "Error Code 10", the module will work with earlier versions of the driver.

For Windows 7 64-bit, this version works.  Unzip the file, then in device manager select device properties, update driver, have disk.  For 32-bit windows, this version works fine.

Besides its intended use, I have used it as a breadboard 3.3 & 5v power supply with a USB extension cable to a 5v USB power supply (or a computer USB port).

I also find the adapters handy as a simple voltage tester.  The T and R LEDs light up when pulled to ground, so I'll attach them to MCU pins to check for pulses.


  1. Update: I've found that when the serial adapter is plugged into a different USB port, windows sometimes uses the default version of the driver ( in Windows 7). This might be avoided by deleting the driver file: C:\Windows\System32\drivers\ser2pl64.sys and delete it from driverstore (C:\Windows\System32\DriverStore\FileRepository).

  2. Awesome! I've got a number of these things and want to use them in a project that many folks will use, so they needed to work with Windows 7 and Windows 8. I had nearly given up on them and was going to pursue another avenue when I found this. The earlier Windows 7 drivers works great with Windows 8.1. Thanks very much! Good blog, btw.

    1. Glad you found some help from my blog. Also interesting that both of us have been playing with 433mhz modules lately.