Pulse info of signal from Futaba Transmitter

[gonwei]

Hi all,

I desperately need help here for my project... I need to get the pulse information of the signal transmitted from a Futaba transmitter. The transmitter has a trainer socket with DIN 6-pin configuration.

I tried using PULSIN command to read from one of the pins on a BS2 stamp. I observed that it read 0 when no wire is connected to it, however once i plug in wire it'll give random readings, i suppose that's noise, is it?

Another funny observation is when i touch the wire (connected to the pin on BS2 stamp) on the transmitter's antenna, the servos (i was·trying this experiment·on a BOE-BOT Board of Education) moved at random patterns. I don't understand why... http://forums.parallax.com/images/smilies/freaked.gif

Can some kind souls pls help to explain why the above observations happen and how should i actually obtain the pulse signal information from the transmitter using the stamp? http://forums.parallax.com/images/smilies/confused.gif
Thanks in advance!

kevin

[Bruce Bates]

kevin -

Let's start with this. Generally speaking you don't obtain the pulse information from a transmitter, you receive pulse information from the RECEIVER. The receiver obtains the pulse information from the transmitter.

Additionally, any time you do not have a solid electrical connection from a reliable source on a micro-controller pin, one can expect any sorts of random garbage on the pin port. Even the type and value range of the garbage is not particularly predictable.

Regards,

Bruce Bates

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[allanlane5]

Isn't the 'trainer socket' so a trainer can co-control the controlled device along with the student? In which case, it may be an input, not an output.

Even if it IS designed to hard-wire to a Reciever module, it's the output of the Reciever module you want, not the multiplexed RF signal output by the controller. The Servo control signal is a 1 mSec to 2 mSec (depending on command position) pulse, repeated every 20 mSec to 50 mSec. THAT'S what the BS2 can both recieve (with PULSIN) and send (with PULSOUT).

Hmm.· A quick perusal of the RF Transmitter docs reveals you CAN use the "DSC" connection to hard-wire to a reciever module.· That's what you'll have to do.· Then, you can connect the 'signal' part of the output of the reciever to the BS2.

Post Edited (allanlane5) : 11/14/2006 3:34:43 PM GMT

[gonwei]

First of all, big big THANKS Bruce and allanlane for the quick replies! =)

I stil have some doubts here:
allan: What do you mean by "...use the "DSC" connection to hard-wire to a reciever module."? What is a DSC connection? How can i do that? Any electronics gadget i need? Sory i'm a total beginner in electronics...

Thanks again! Hope to hear from you again.

kevin

[allanlane5]

On the Futaba web-site they have a "DSC" cable. Apparently it plugs in to the 'Trainer' socket on the RF Remote, and the other end plugs in to a "B/C" socket on the reciever. This gives you a hard-wired connection from the Remote to the Reciever.

The Reciever then breaks out the signals from the remote, and routes the appropriate signal to servo 1,2,3,4...

I suspect the signal on the "DSC" cable is the multiplexed servo signals, which the reciever knows how to de-multiplex. I have NO idea what the multiplexed signal looks like, though.

[dandreae]

I have a sample code here that uses a Futaba radio box.· See if this works?


Dave

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Dave Andreae

Parallax Tech Support

[allanlane5]

Yup, that should work, alright, BUT it does require a Futaba 'Reciever' module.