I've had a few days where I've either done nothing on the robot, or just watched it drive around the house (mostly) avoiding walls and furniture, but usually getting snagged on the rug (the robot has some clearance issues). I'm now in the 24-hour battery recharge cycle.
An interesting observation I've come away with, that will be analysed more thoroughly over the weekend, is the spotty performance of the SRF04 in 'hard' environments. By hard I don't mean outdoors, rough terrain. I mean in my passageway. My house is about 80 years old, with thick plaster covered walls, fairly tall, glossy, wooden skirting board, and polished wood floors. When the robot approaches the wall from an angle of 30deg or more away from the normal, it doesn't get a good range reading at all - it's like the wall isn't there. Then, all of a sudden it will get reflections when it is very close and execute the emergency reverse, then almost instantly get back to the invisible zone. It doesn't do this in my bedroom.
In general though, I like the SRF04 - I think it's very accurate - within 1 cm in the ranges of interest to me - and using the driver is a snap.
I'm going to integrate the Sharp IR ranger next .. hopefully that won't take 3 weeks!
Have a good w/e.