Quote Originally Posted by dsheller
I'm using the ultrasonic sensor called PING))) from parallax, it works really well up to ~3 meters... I'm using it on an ATmega168 and capturing it's echo. The kicker with this one is it has only 3 pins, Vcc/Gnd/Sig... so essentially you send a 5 uS pulse through Sig and wait 750 uS (Echo Holdoff). After the signal you'll get a PWM signal which is directly correlated to how far the object is... I get good readings assuming I am using a good value for the speed of sound =)
That's good to know. I'm using the SRF08 sensors. They are supposed to return the first 17 echoes, but what I have found in testing is that they appear accurate for less than 1 meter, and all the echoes beyond that remain basically the same, regardless of what's out there. The one real advantage to them is that they work off the I2C bus, which means that I am using only 1 IO port for five sensors. The other good thing about them is that power consumption is minimal. Those Sharp IR sensors draw an insane amount of power, even in standby. I was trying to use a couple FETs to toggle the IR sensor on and off, but it made the sensors a bit quirky.

EDIT: Forgot to ask you what type of bluetooh module you're using... I'm considering going with something called Zigbee myself. The only problem with that is I don't know if I could use it to talk to a laptop... for robot to robot communication it looks great though.
I bought the bluetooth chip from SparkFun, along with a bluetooth dongle. I forget the specs on it (BlueSoleil, I think), but last time I looked, they had changed their lineup somewhat. The chip is on a small IC board with a simple pinout. You can get it with and without an external antenna.