RC car idea

[themadhacker]

I am in the process of using some free RC cars I got to make a cheap**s remot controlled robot, but I might need three different cars to make it. That means they have to be three diferent frequencies. I then had an idea. What if I added two identical crystals in the controller and the matching car. would It be able to run at the same time as another car with the same frequency the moddified car previously had? That way I would be able to run the 20 something mhz car with the 49 mhz car and the car with the new crystal all at the same time.

Regards, Bill

[XCVG]

What if I added two identical crystals in the controller and the matching car.

You could probably do it, but you want to use a similar-ish frequency, you need to check what the crystal is before you do it (it could be multiplied), and the the FCC will try to kill you.

[themadhacker]

and the the FCC will try to kill you.

whty the heck would they do that?

[XCVG]

Because it's tampering with the transmission circuits which could cause interference or something. They should be called the IPC- Interference Paranoia Comission. They are the same group that mandates the use of excessive shielding with no purpose.

[rcpitlane]

I think the reciever with the same crystal will just glitch back and forth. The anteneas will be too close and you will just get a lot of cross talk. Not to mention that going am or even FM will cause a lot of interferance if you go with a lot of metal on metal moving parts. Why not get a used Spektrum DX controller and reciever off ebay? They are 2.4 ghz, no crystals. And you can get them in like 6, 8, or 9 channels. Not the cheapeast solution, but it makes the most sense. Or go with a helicopter radio/transmitter. They are usually good for about 6 channels.

[XCVG]

Or build your own controller out of a few AVRs and XBee modules.