Usb to Serial/TTL Adapter




Master Diesel Tech, in California. I love electronics and everything science .

hello guys this is my first post so bear with me. I order a usb to serial adaptor  for $1.78 from ebay and wanted to try and make it work. since there is no information from the seller exept that is based on the PL2303. Since we have no info and no drivers I decided to google and I found a driver that might work  it comes from prolific

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Drivers Installation

we download the driver and we unzip the files. then we run the driver installation program. I am not going to post pictures and step by step instructions because all you have to do is click "ok" and "install".

Step 2: Connecting the Adapter

now that the software is done installing just hit "Finish" and connect the adapter to you computers usb port. the hardware wizard pops up and it automaticly installs the driver for you. We can check our installation by going  in to the device manager and  ports.

Step 3: Verify the Installation

we now have to verify the installation, we see in the device manager that it has installed right and the it is set  as COM5. the driver comes with a  utility that verifies the  chip version just go to the driver folder that was unzip earlier and run checkchipversion.exe  we set it to COM5 and we click on "check" it will give you the chip you have since there are a lot of versions of the PL2303.

Step 4: Testing Our Adapter

we can test our adapter using the arduino IDE. we change the port to COM5 and we put a jumper on the adapters pin TXD and RXD.

Step 5: "Hello World"

We open the the serial monitor and we type "hello world"....and we are done.. that's all folks.  I am working on some projects to test the capabilities of the PL2303 will post the later. that's all for today and this was my first instructable ever so bear with me.

Be the First to Share


    • Made with Math Contest

      Made with Math Contest
    • Multi-Discipline Contest

      Multi-Discipline Contest
    • Robotics Contest

      Robotics Contest

    18 Discussions


    Question 3 months ago on Introduction

    Hi guys, I bought a device like this, with rx tx gnd 3.3 5 I would like to use it as a serial comms port, but it doesn't work. Is the device created only to communicate with arduinos and similars?
    thanks luis

    1 answer

    Answer 16 days ago

    I think you may need to install the CH340 driver if you are using Windows 10


    Question 7 months ago on Step 2

    I've already installed the driver but the problem is always there


    Question 1 year ago on Step 4

    i have this same usb serial but i want to connect it with fpga board having jtag on it .Im confusing in that TXD and RXD where to connect on that jtag header having 10 pins (TDI, TDO, TCK ,TMO)


    Reply 2 years ago

    I also had this issue with Windows 10. Worked fine under Windows 7. I found this "older" driver that works with Windows 10 and I am using the adapter again!


    3 years ago

    I have a question. I have installed windows 10 and I can't seem to make it work.Allthough the drivers are installed and the pc shows in device manager the usb and the COM it says that it is not possible to start the device.Furthermore in the program that was included in the drivers I downloaded when I try to check my Usb in the correct COM it says "OPEN COM PORT FAILED" . What shoud I do? Thanks in advance

    1 reply

    3 years ago

    Hi Verdelj, Can I ask which programmer you have selected in the Tools>Programmer?


    3 years ago

    Thank you so much. :D


    4 years ago

    I have same adapter, before I tried with many prolific drivers but did not work. With your zip file worked. Finally I can use my TTL adapter. Thank you.


    Reply 4 years ago

    Try to create a new sketch and see if it works.


    6 years ago on Introduction

    well the pl2303 has pin 3 wich is RTS (Request to send ) and DTR (Data terminal Ready) on pin 2 that can be used to interface with I2C .....
    DTR to i2c-SDA and
    RTS to i2c-SCLK
    ..I would need to go back and take a look at my c++ books but I think I can write some software that would let me talk to some I2C modules . I think I have a ds1307 somewhere.


    6 years ago on Introduction

    Very promising little gizmo. I'm thinking next you need to figure out a CLK pin to do some serious damage. (Directly connect I2C, SPI, etc, chips)