Let's Make Robots!

ultrasonic 1 transducer vs. 2



why dont we see robots made with these? http://www.sparkfun.com/commerce/product_info.php?products_id=8502

is there something bad about it having 1 transducer only? sparkfun does not carry the SRF05, so will this be a viable replacement?

Servo fighting with Sonic sensor

Sending out a pulse with my parallax ping)) often causes my servo to inexpilcably jerk, jitter, stutter, or shake. Is this a common issue? How do i avoid this and why are they conflicting?

how does the robot know what pos his servo is at?

i realize the servo is only connected to an "out" pin. is there some popular method people use to have the servo tell us:

"ive arrived at my destination"

My purpose is to have the sonar fire when the servo is at a specified location. w/o relying on iffy pause timers. (which stop everyhting else from what i know)

I want to use C or C++

Mostly because i work using C++ in the office and feel at home with it. (plus i get wierd looks when i tell people i use basic to make my robot, mostly faces that resemble smelling a fart)

I gather i cannot do it using the picaxe stuff... Do many peopl here use C for their projects?  How do i do this and what would i need?

Ordered all the parts in "How to make your first robot"

I ordered them 2 days ago, I hope i didnt miss anything. it took me about 5 hours to read up and make absolutely sure i knew what i was buying. took me long because i was also comparing prices.

i had no tools so i bought them too. the 3 stores i used were pololu, sparkfun and hobby engineering. The whole "first robot" package if you have absolutely nothing, is realistically about $170 (includes tax and shipping)