MightyOhm.com

I plan on hacking up a WL-520GU for a similar project. In the tutorial, an FTDI 3.3V device is used to access the serial port with your PC.

I just recently picked up a FTDI Basic adapter from sparkfun
http://www.sparkfun.com/products/9716

It is a 5V part. I'm assuming I can use it on the 3.3V serial port on the Asus. (if 3.3V would be enough to register a logic high; can't seem to find it in the datasheet)
Do you think it would work?
I'm thinking that the 3.3V from the RX of the Asus will be enough to register logic high on the FTDI, but then the 5V from the TX line on the FTDI might damage the RX on the Asus.

The FTDI Basic adapter can be modified to operate in 5V or 3.3V mode by cutting/soldering jumpers, but i think i will modify (if needed) with a switch for quick changes.
Thanks

It might work, but I wouldn't recommend it. There is no guarantee that the 3.3V IO lines on the WL-520gU can take 5V without blowing up. You generally don't want to send voltages higher than 3.3V to IO pins that run at 3.3V.

I would modify the adapter to run at 3.3V for this project and buy another one (I think Adafruit has one too) for 5V projects. You can't have too many USB-serial adapters.

Thanks for the response and confirming my hunches. I will modify it, it shouldn't be too hard. Thx

Serial TTL devices that operate with 0-5V levels will successfully read 3.3V logic-level data.

Therefore, you can just keep only 3.3V FTDI modules and cables on hand, and you can use them successfully on all 3.3V and 5V embedded TTL-level-UART devices, without any risk of blowing anything up, without needing to buy both 5 V and 3.3V versions.