Can someone give me a reference(s) to locate information, and prefably off the shelf hardware including DTMF decoder and servo operation (3) for plane. Will use OPV for camera etc. So all I need is the hardware and apps to run 3 servos between 2 phones .
maybe if you told us what you are actually trying to do, we could be helpful. "DTMF decoder and servo operation for plane" is rather vague, to say the least.
Also, you don't tell us what "OPV" is either.
Apologies for not explaining enough. Firstly OPV stands for 'Original Person View'. There are a number of packages available that give camera views from plane onto smartphone hand held.
My wish is to be able to operate r/c type 3 servos from the plane based phone thru a DTMF decoder. I would operate the OPV as a separate system onboard but simultaneously.
I also must admit that I want to use this setup in a ground based vehicle. Saw the discussions on this list and felt it would be suitable for my purpose. I am quite happy to discuss offline at
Your comments would be appreciated.
Thanks and regards
I think what you mean then is "FPV" which is "First Person View"? FPV is a very popular acronym: http://en.wikipedia.org/wiki/First_Person_View. If OPV means anything different, google was unable to tell me.
As for using DTMF audio tones over a mobile phone link to "steer" your vehicle, there are a few downsides:
(1) you must make and persist a phone-call between both phones for the duration of each flight/drive
(2) there are only approx 10-16 DTMF tones available, and they are either on or off, so you can not "steer" in small increments, it's just 16 bits of data, total. A typical RC system uses at least 10 bits per channel, and 8 channels, resulting in ~80bits of control data.
(3) the standard length of each DTMF tone is 70 ms, meaning you can send at most 14 ( 1000/70 ) of these tones per second ( 14Hz), and only one at a time in each audio channel ( perhaps two if using stereo?) This is in comparison to using at least 50Hz, or even higher in most Rc units.
You are extremely limited in the type and usefulness of a system like this, especially if you want to use it for any analog outputs ( such as steering or flying )
Actually OPV stands for Optionally Piloted Vehicle the Kaman Kmax is just one example.