I am trying to interface my Arduino Duemilanove with a WiFi Module ( http://www.drrobot.com/products_item.asp?itemNumber=WFS802g ). The Module has a TTL 3.3 V serial interface that has been set to 9600 baud, no flow control, 8 bit, no parity, 1 stop.
I have used an oscilloscope to view the incoming serial data (on the WiFi Module's TX pin), which verifies the functionality of my data source and WiFi Module itself. The voltage level seen is about 3.2V.
With my Arduino Sketch, I have also been successful in using the included Serial Monitor to verify the functionality of my program over USB (by typing packets within the monitor and viewing external LED changes, etc.)
My issue is with interfacing the two together. I connect the TX pin of the WiFi Module to the RX pin of my Arduino, and then send packets wirelessly to the WiFi Module. When I do this, Arduino does not seem to do anything (no external LED changes, etc.)
I am confident that the WiFi Module is receiving the data properly (since it has been verified), and that the data is on its TX pin. Since this is connected directly to the Arduino RX, I think there may be an issue in incompatibility between the two devices (possibly due to voltage levels). I was not able to find a spec regarding this, so I was hoping for some feedback or assistance.