This is what you get from ebay for a very cheap price
Most cheap PL2303HX USB to UART adaptors from ebay usually don’t have DTR pin to upload sketch easier to Arduino Mini Pro.
This post will show you how to mod this little adaptor to play nice with arduino mini pro. It should take about 10 minutes and require good solder skill.
The circuit
This is how you do it:
Step by step
Finish
You can use sticky tape to cover the text “3.3v”.
Compare with the other version I have at hand
Driver for windows 10 - PL2303HX
[attach=downloads/Profilic_PL2303HXA_Win10_x64_x86.zip]Profilic_PL2303HXA_Win10_x64_x86.zip[/attach]
It’s funny when the old driver works fine in windows 10 but the newer ones are not.
Edit:
Alternately, you can use CP2102 USB to Serial Converter instead of PL2303 as windows 10 automatically recognizes it. No driver hassle. It also has DTR pin and some other useful pins as well.
[tag]UART, PL2303[/tag]