Page 227 - Hacking Roomba

208 Part III — More Complex Interfacing

To use your existing serial tether and a SitePlayer Telnet System box, you need:

NetMedia SitePlayer Telnet System, NetMedia part number SPTS

And that’s it. That isn’t a very elegant solution, so if you want to build your own Ethernet-to-
Roomba interface, the parts you need are:

NetMedia SitePlayer Telnet Module, NetMedia part number SPT1
LF1S022 10base-T filter, NetMedia part number FIL0011F
Mini-DIN 8-pin cable, Jameco part number 10604
7805 +5 VDC voltage regulator, Jameco part number 51262
220-ohm resistor (red-red-brown color code), Jameco part number 107941
Two 1µF polarized electrolytic capacitors, Jameco part number 94160PS

8-pin header receptacle, Jameco part number 70754
Male snap-apart header, Jameco part number 160881
General-purpose circuit board, Radio Shack part number 276-150
Four 0.01µF ceramic disc capacitors, Jameco part number 15229

Finally, if you want to experiment with the Lantronix parts, the easiest path is to get the XPort
evaluation kit:

Lantronix XPort Evaluation Kit, Mouser part number XP100200K-03
NetMedia sells the SitePlayer modules and 10base-T filters direct from the company’s website,
at http://siteplayer.com/. The best way to get Lantronix parts is through Mouser, at
http://mouser.com/.

SitePlayer Telnet

Several years ago NetMedia came out with the SitePlayer module. The SitePlayer is a small
(about 1 sq. in.) and cheap ($29) website co-processor meant to integrate to an existing micro-
controller. On the SitePlayer you could store a tiny dynamic website. The web pages on that
site could change memory values in the SitePlayer or toggle pins, and the microcontroller could
do the same. It gained renown among microcontroller hobbyists as the cheapest and easiest
way to get a project on the Net. What it couldn’t do was create a straight tunnel between the
Net and a serial port.
In late 2004 NetMedia released the first version of the SitePlayer Telnet (SPT), the same hard-
ware as a normal SitePlayer, at the same price, but specially configured to be an Ethernet-to-
serial converter. It runs a Telnet server whose input and output go to a serial port. The initial