Roomba not responding to roombacomm

I've got a Discovery serie开发者_C百科s iRobot Roomba and an iRobot Create USB cable. I've hooked them up to my Ubuntu 10.04 laptop. The roombacomm software recognizes the /dev/ttyUSB0 connection, and when I send commands the cable's LEDs light up, but the Roomba is unresponsive :( The software has the message: "Checking for Roomba... No Roomba. :( Is it turned on?" (The Roomba is turned on.)

The software has the same error message if the Roomba is not plugged into the Create cable. The cable does not light up when the Roomba is not plugged in. The cable lights up in the middle when it's plugged in to the Roomba, and on one side when a command is issued through the roombacomm GUI. So the GUI must have the correct port and be talking to the cable.

Do you have any troubleshooting tips? Are there any alternative software libraries I could try?

Thanks! --Erin

Perhaps you're using the wrong port. These instructions at iRobotReviews suggest using a higher numbered port to avoid conflicts.

Not all Discovery series Roombas have the Open Interface installed. http://en.wikipedia.org/wiki/Roomba#Hacking_and_extending_Roomba

If you're sure that your Roomba can be programmed, try using a terminal program. Turn on Roomba while listening with the terminal program at 57600 bps (8n1). You'll see a stream of data. To test outgoing data, send a 128 (number, not ascii). You should hear a beep from the Roomba.

If your Roomba doesn't respond to a 128, you may need to acquire a "Hacker Osmo". You can still get them from various third parties.