No, I'm not talking about the USB Dongle.
I spent a week in Rolla over last summer for an Intro to Engineering Camp and in the Computer Engineering presentation, I got a small 3''x3'' circuit board with a cheap little microprocessor built in. The IO consists simply of four switches, four LEDs and a basic speaker. I'm going to replicate it a few times so each of our prospective programmers for next year can play around with them and get a feel for how microcontrollers work. The board utilizes a 9-pin serial port for program loading, much like the FIRST RC. Our school provides laptops for every student (except our Senior class. We were the last class to not get them), but none of them have a 9-pin serial port.
I know the basic background of how the 9-pin serial port works (RS232, I believe. Correct me if I'm wrong), but USB is very sketchy. I figured someone around here knows enough to help me. Am I correct in saying that USB is basically a 4 pin serial port that uses a +5V pin, a Tx pin, an Rx pin, and a Ground pin? If so, could I make a custom cable that wires the USB's Tx to the 9-Pin's Rx (In addition to using 9-pin serial, the board is designed so that you have to use a Null-Modem cable), and so forth?
Code:
RS232 USB
----- ---
1:DCD +5V
2:RxD--------Data-
3:TxD--------Data+
4:DTR |-Gnd
5:Gnd------|
6:DSR
7:RTS
8:CTS
9:RI
I'm just hoping I don't have to actually go out and buy USB to 9-Pin Serial converters for everyone. I bought one for myself a while back, before I knew a whole lot about this stuff (though I still don't), and if I remember correctly, buying one for every member might get expensive.