[757labs] Augmented Reality Storage

[Jody Franklin]

On Jan 15, 2010, at 17:36, ethan at 757.org wrote:

>> The board I have uses a FTDI FT232RL to provide serial <-> USB connection. The chip does RS232 9600 8N1 for serial.
> 
> Interesting. I'm not sure that the commercial hardwarez use RS232 for the readers, because rs232 doesn't go far. But it might be something like 422 or 485 or something. One of them is just the same data with a different voltage. The other is differential. All of them are the same signaling I think.

Per the manual you sent me the link to the board you have will support either 485 or 232. In theory 232 should support 50 ft, though there might be ways to play with that. I've been looking for ICs to do conversion and it's going to be about $20 or so. $15 if bought in lots of 25 or more. Might be cheaper ways to do it, but I think in the end we might be better off using readers that do native 485 when exceeding the 232 run length, or perhaps using a relay to extend the range, which shouldn't be too expensive.


- Jody