# Society of Robots - Robot Forum

## Electronics => Electronics => Topic started by: rabi_tagore on January 21, 2007, 10:06:50 PM

Title: Two Transmitters on One Receiver!??
Post by: rabi_tagore on January 21, 2007, 10:06:50 PM
Hey,
I am constructing my first robot and am in high school, so I do not have great exposure to robot construction.
Now that my intro is done, here's my question:
Is it possible to use TWO 4-channel transmitters to control a robot that is equipped with only ONE 8-channel receiver?

I think I know what I have to do, but am not very sure how to implement my idea. Since every channel has a (slightly)different frequency, I could possibly assign the first 4 channels on the receiver to the first transmitter, and the second four channels on the receiver to the second transmitter. However, this assigning of channels is what is creating a problem for me. First, is it possible to assign channels like that? If it is not, could other ideas work?

More background info:
The 2 transmitters are Hitec Laser 4 75Mhz(surface, 4 channels) each, and the receiver is a regular surface 8-channel receiver.
Our school's budget, my limited knowledge, and the remaining time unfortunately do not let me explore microcontrollers and some 7-channel programmable transmitters. However I will learn how to work with 'em if those are what are required for my job. Just waiting for ur feedback....

Thanks a lot
Title: Re: Two Transmitters on One Receiver!??
Post by: gamefreak on January 22, 2007, 07:34:49 PM
lol i dont have a clue about RC, and hey im in highschool as well(the only one who knows anything about robots  :(), But no i dont think this would work. Since the transmission is a certain frequency each channel is looking for a specific frequency and i dont beleive you can do that.
Title: Re: Two Transmitters on One Receiver!??
Post by: dunk on January 23, 2007, 03:41:30 AM
why do you need to use the same receiver?
why not just use separate 4 channel receivers for each transmitter, both operating on different frequencies?

dunk.
Title: Re: Two Transmitters on One Receiver!??
Post by: Admin on January 23, 2007, 08:10:56 AM
if you have a programmable remote, i think you can select which channels are used, allowing two remotes for one receiver . . . not sure though . . .

this is the remote i have sitting on my desk right now:
http://www.hitecrcd.com/Support/Manuals/Radio/OpticTutorial.pdf
it has some programming functionality, but ive never needed that yet - not sure what it can do . . . check the manual . . .

Quote
why not just use separate 4 channel receivers for each transmitter, both operating on different frequencies?
probably the easiest way to go about it. i did that for this robot:
http://www.societyofrobots.com/images/sumo_robot.jpg
getting two people to control one robot as a team was the hard part . . . :P
Title: Re: Two Transmitters on One Receiver!??
Post by: rabi_tagore on January 23, 2007, 01:52:42 PM
I guess I will just stick to the sumo_robot design. It seems to be the easiest to implement. I was just trying to avoid the use of another receiver, but it's alright.

Thanks a lot.
Title: Re: Two Transmitters on One Receiver!??
Post by: gamefreak on January 24, 2007, 08:12:15 PM
lol, something just hit me, if both or your remotes are on the same frequency then as long as you dont try to do forward and back at the same time(or something similiar to that) then technically it should work. one person does left/right, and other does up/down, then as long as you dont try to do opposite signals then there souldnt be interference.