Hola.
I recently bought 2 HAC-UM96 modems and wish to connect one of them to the Bot board II (Driven by a Basic Atom Pro 28) and one to the PC.
I don’t have the slightest clue as to how to accomplish that.
Can anyone give me some pointers? like, where on the bot board should i connect it, the DB9 or the I/O pins? How should i connect the modem to the DB9 on the PC?
Did you read the info available at Spark Fun on the HAC-UM96? It only takes a bit of research in many cases to find out what you need to know to do what you want to do. 
Doing a simple Google search for “HAC-UM96” turns up all kinds of information. 
8-Dale
Of course i searched google and the HAC-UM96 datasheet before i wrote here. I’m not THAT lazy. But i’m quite new to the whole MCUs stuff. As I understand it, I can connect the modem to the DB9 on the PC but I don’t know if I need anything in between them because the modem runs on 5V and the PC is supposed to send out RS232 ±12V.
Also, I don’t understand the difference between connecting the modem to any of the I/O pins on the Bot Board II and the DB9 connector on the board?
Could you clarify on that PLEASE???
The information on Spark Fun is quite good. 
This has to do just with the standard RS-232 connection between PC and modem or microcontroller and modem if using RS-232 (not 5V TTL level). A 5V TTL level connection can be used to interface directly to the I/O pins on a microcontroller.
Connecting to the DB9 is standard RS-232 serial you can connect direct to a PC serial port.
If you connect it to the I/O pins on the Bot Board II, that is a standard 5V TTL level serial connection. You can use this to provide a transparent wireless connection between the Bot Board II and any other HAC-UM96 modem. It does not matter how the modem on the other end is connected - it could be TTL level to another microcontroller or RS-232 to a microcontroller or PC.
8-Dale
Thank you. That was exactly the answer I wanted. now, as I understand it, I need to I/O pins for RxD and TxD (one pin for each function), one for the 5V Vcc and 2 for 0V (one for GND and the second for SGND). Does it matter if I use P0, P12, P6… or any of the other pins, or are all the pins on the Bot Board II the same?
You just need one pin for GND. It does not matter which I/O pins you use for RX and TX. You just have to make sure the pins you choose do not conflict with any other functions you want to use, such as P9 for the speaker.
8-Dale
Does a modem have to be the first connection from the outside box? I am thinking about putting the modem in a location that would have the coax connection pass 2 splitters before getting to the modem. Is this ok?
external keyword tool ~ keyworddiscovery.com ~ keycompete.com ~ compete.com ~ webmasterworld.com