Hi! Can I connect the TX RX of the AC4790 to the Generic I/O of a Z8F462X??? Or should I use the UART of the Zilog with MAX 232 converter before connecting it to the AC4790?
Tnx!!! I am really having a problem in interfacing the AC4790 with my Zilog.
Looks like a nice little unit. The manufacturer website says it wants 3-5V TTL on the serial interface, so no MAX232 needed. In fact, the 12V from standard RS232 might kill the unit. Try using the UART on your micro to talk to it. It looks like any standard baud rate should work fine. I’d try slower first, say 4800? Then work your way up. Looks like it has buffering, it can talk to the micro faster than it can handle data on the radio side. Check for any handshaking signals it wants to see, like CTS/RTS etc… The datasheet is your friend. 
Looks like a nice part, mind sharing the cost and source? Others here might want to try working with it.
If you can’t get your micro talking to it, use the MAX232 and connect it to a computer serial port. See if that works. Then you know if it’s something about your micro’s setup or code.