RS232 Adapter boards

I was recently given 10 x HC340G USB to serial adapters that was purchased by a school complaining they didnt work with picaxe, well we all know why these boards dont sometimes work unless you invert the data lines (serin and serout).

Then i stumbled across these RS232 boards, being cheap enough to try as inverter add on boards.

http://www.ebay.com.au/itm/5-x-Mini-RS232-to-TTL-Converter-Module-Board-SH-/252652268840?hash=item3ad33fad28:g:qAMAAOSwj85YN9cC

Its been some years since i worked with RS232 chips, but if memory serves me correct i should be able to connect serial out of the usb board to TTL serial in of the RS232 board and vise versa for the serial in from usb, and end up with inverted RS232 data pins on the output side of the RS232 board.

Have not received the RS232 boards yet to try this, but can anyone see that this wont work.

Here is an example of a different adapter board to show the basic idea if i reverse the inputs/outputs.

Should work fine.

I have even eliminated the caps on similar RS232 Chips and used them as TTL to TTL inverters ... so no RS232 voltage levels to deal with.

A wise man named Bill once told me that if you use a 74HC14 inverter then you should ground all unused input pins to avoid oscillation.

Hey I know that Guy !

I use exactly those boards to add "real" serial interfaces to my picaxe projects. They save a lot of time, space and $$ over using the individual chip and caps. The downside is that the format with one channel on the top surface and one channel on the bottom surface makes them mechanically hard to use tidily on a board because you can't use regular pin headers. If anyone has a good suggestion for that I would be interested to hear it.