what about a quadcopter that looks at the ceiling with an ultrasonic eye & uses it as a height reference? this could be implemented quickly. ceilings tend to be unobstructed & level and would give a good reflection, even variations such as light…
"thereby hangs a very strange tail. But I won't trouble you with it just now.
The simplest way to receve it is to connect an RC diode across the transducer (ie in parallel) also ye olde voltmeter. I suppose if you modulated the transmitted signal at…"
"because my knowledge of electronics is self-taught it has a lot of holes in it & one particularly gaping one is how to increase the strength of an ultrasound signal. Because I never found out how to do this I have always focussed more on how to…"
"I think you may find you get the same ultrasound signal strength without a transistor. The ultrasound transducers have an extremely high impedance. I forget what it is but it's tens of thousands of kilohms."
"If you have a sillyscope a good way to start is connect an ultrasound transducer to its input then connect another one to something that generates a 38 KHz signal eg a 555 timer or a signal generator if you have one.
Now just try looking at the…"
"I have just posted the following on Chris Anderson's blog about multiple IR blimp beacons at the DIY drones sight I don't suppose anyone will read it but I think you might be interested...............
"I was very interested to read G Bulmer's ideas about ultrasound. If you were to move the ultrasound receiver on the blimp to the top of the envelope pointing upwards not only would you be able to use the perfectly flat & unobstructed ceiling as a…"
"because most domestic environments are very cluttered, wouldn't the ultrasonic eye be better employed using the ceiling as a height datum? What about unsoldering the ultrasound transducer & putting it on top of the blimp facing upwards then removing…"