NEED SOME R/C ADVICE

Technical Technical Discussion
#1

Hello,

I am having trouble finding a r/c package to suit my needs…

I need a FM remote transmitter / reciever package…with pushbuttons (that keep the circuit energized as long as the button is pressed)…300 + ft. range…4 channels…the reciever outputs need to provide 12v (actually if it will just put out enough power to pull in a relay coil, I could supply the 12v from there)~

If nobody knows of a setup that fits my specific requirements, please tell me what the closest thing would be…

Currently, I am using a airplane r/c setup…but, the reciever just has a signal output for the servos…unless I use a ESC controller…but, I can only use 1 per reciever (certainly do not want more than one reciever to deal with…)

BTW: Check out more pics and video of my robot “SCHIZOPHRENIA” @ www.radicalbed.com

I appreciate your help,

Jamie

http://www.radicalbed.com/sitebuildercontent/sitebuilderpictures/2006performance.jpg

#2

I know this is way overkill, and I’m only suggesting it because it is the only idea I’ve got, but here it is:

Use our Robot Controller and components. A Spike relay would provide 12 volts, depending on how you had it programmed.

This is going to blow any budget you might have and it, like I said, is way overkill, but I don’t have any other suggestions. Oh, and I’m not sure what the range on our radios is like. I’ve never seen it above 100’ but I haven’t tried.

Good luck on your project,
JBot

EDIT: Here’s the link: http://www.ifirobotics.com/

#3

The link of our radios is more than long enough. We drove a bot across the school without being able to see it. It went at least 200 yards before it wouldn’t control anymore.

#4

What about a Vex controller? The kit can be made to work with relays, has a nice FM radio, runs off of AAs or rechargeables (your choice), you can add in a kill switch to the back of the radio (probably a good thing for something with that much power), it can tether when you want to test radio-free, and it has plenty of room for expansion. (Autonomous programs, anyone?)

A Vex kit goes for $299, and the programming kit (which you may or may not need, depending on what you need or if your friend has one) is $99. It’s not that bad a deal–you might just build a Vex robot with it, too. :wink:

#5

I know you didn’t ask, but the FCC won’t be too happy with you if you use an aircraft frequency with a ground vehicle. So whatever you choose, make sure it operates on the correct band (e.g. 75 MHz band, like the Vex controller).

Also, avoid large, garish, red text.

#6

I second using a vex controller, they work very well as an inexpensive FM reciever as well as a programmable controller if that’s a need too.

Personally, *(http://www.chiefdelphi.com/forums/showthread.php?p=518568&highlight=hpc#post518568). It works very well and is much less expensive than a robot controller if youre handy with C programming. You just make up a progam on one HPC for the OI pannel that reads in analog voltages and some digital input, some output if you want, and packages it into a string.

Then, the recieving end just has to take the analog/digital inputs and make them into pwms or just simply copy the digital in to and out.

For wireless between the two, i like to use a MaxStream data modem. And for range… the Xtend modem has a range of 40miles line of sightwith no FCC license needed, 256bit encryption and internal data packetization. :smiley:

Just hook up RS-232/485 or near any interface of your choice to the modems, and bingo, wireless data. These can also be used in a network mode if you need to communicate with multiple devices.

Good luck!

-Q*

#7

You should be able to control a spike with a regular RC transmitter and reciever. You may have to add a PWM Signal Driver, which is a PWM cable with a little circuit in it. Here is a link to the driver.


It is the sixth item down. $15

#8

I don’t think so. The spike needs no digital signal. It just needs voltage (how much, I’m not sure) to the white wire in the PWM cable for forward and voltage to the red for reverse. I think 5 volts should do it.

If using a Victor, you’ll need a PWM signal driver.

DUH! Why didn’t I think of using VEX?! That’ll do the same job for much less…

Good luck,
JBot

#9

Yes you are correct. Thanks for catching my screwup.
Sorry was thinking 0 was off and 254 was on.

#10

Well, just responding to your first part saying the receiver needs to put out 12 volts. That’s a problem considering you should only be putting in ~5 volts, I’m not sure if you know this or not.

But as people have been saying, you can just hook a 12 volt battery up to a remote switching system and then wire the PWM of the switch to the receiver.

People are suggesting standard FIRST relays, I would suggest a Team Delta RCE210 Switch (http://www.robotcombat.com/marketplace_teamdelta_rc.html, scroll down to see it.) It is around the same price as a spike, it can handle 24 amps which is 4 more then a spike and go up to 30 volts as where a spike can only go to 12 volts. You many not need 30 volts, but if you ever want to upgrade you don’t have to buy a new system.

As far as a radio, without knowing what FM radio you have now I can’t really tell you if you should upgrade or not. If you didn’t have a radio and I was recommending one, I would say the Spektrum 6 Channel system.(http://www.robotcombat.com/marketplace_rc_radioDX6.html) It is a standard 6 channel aircraft style remote on the 2.4ghz frequency so there is no interference. The only reason I linked you to the Robot Marketplace again is because they have the specially designed BR6000 receiver there. The original receiver doesn’t have a failsafe so when you loose signal the robot keeps going. This is a big problem in combat robots (another thing I do) so Spektrum designed a special robot receiver with a failsafe. I would definitely suggest that you get this considering that if your project goes awry you would have a big problem.

-Greg

#11

Some notes on this: You will most likely be fine with a vex system if you use the vex controller module and vex receiver. Do not attempt to use the vex system for integration with a standard Futaba-like receiver. From experience the system does not work nearly as well as you would expect. I have yet to figure out the reasoning behind it, I suspect it was a power issue in the receiver which may just have been the one I used.

From other RC experience I would say at least get a PCM receiver, or one of the newer ones based off of the 802. system. The newer radios have the ability to “lock” into the receiver which basically minimizes radio interference.

no offense to these forums but your questions might be better answered at www.rcuniverse.com they are forums dedicated to RC hobbies, and you may be able to buy something used inexpensively from one of the members.