Society of Robots - Robot Forum

General Misc => Misc => Topic started by: RoboChan on July 20, 2009, 03:51:03 PM

Title: RC radio help
Post by: RoboChan on July 20, 2009, 03:51:03 PM

I dont want to thread jack so im starting this.

I have a exceed dragon fly 20 radio set its 4 channel, 72 MHz so i can use it on the ground. I would like to use it to maybe build a ant or bettle battle bot for http://www.ohiorobotclub.org/. If I buy a resiver how do i hook up 2 or 3 DC motors or servos to it and set my transmitter so when i push the left stick forward 2 motors turn on? In adims vedio for RC he had to push diagnal for the robot to go strait, how would i fix that?

Title: Re: RC radio help
Post by: SmAsH on July 20, 2009, 04:07:53 PM

you would need to get something called a channel mixer.
or you could hook up a small circuit with a microcontroller that reads the pulses.

Title: Re: RC radio help
Post by: Razor Concepts on July 20, 2009, 04:14:18 PM

Buy a RC speed controller, and to control it like you want, buy a V-Tail mixer.

Title: Re: RC radio help
Post by: RoboChan on July 20, 2009, 05:56:37 PM

On the back on the transmitter there is a little red pannle with 8 little switches. is that a channle mixer?

Title: Re: RC radio help
Post by: Joker94 on July 21, 2009, 11:17:49 PM

it could be dose it have any writing or sales code written on it any where. ???

Title: Re: RC radio help
Post by: RoboChan on July 22, 2009, 01:56:33 PM

It has "ON" on the top and "DIP" on the bottom of the red. Theres a vedio on youtube of a gut who used and aduino and remote controlled, 2 dc window motors and a green LED. I just can't find it now.

Title: Re: RC radio help
Post by: izaktj on September 18, 2009, 09:54:08 PM

For the motors to turn forware you need a mixer, or, some radios have the ability to mix as well.
After I crashed my interim UAV platform I moved the electronics to the sumobot chassis and modified slightly into this creepy machine.
(http://i245.photobucket.com/albums/gg50/izaktj/DSCN1260.jpg)
I might take a video later.

For the servo mixing, what happens is the following.
Servo 1 is connected to channel 1 (up/down)
Servo 2 is connected to channel 2 (left/right)

Without mixing, when you press the stick upwards only servo 1 will move forward. When pressing left only servo 2 will move left.
With mixing, when you press stick upwards, both servos move forward, when pressing left one servo moves forward while the other backwards, thus creating turning motion.
It is the same mixing as elevons in RC planes.

Now the other way with a microcontroller, would be something like:

Case (stick up)
{
      Servo 1 = Forward
      Servo 2 = Forward
}
Case (stick down)
{
      Servo 1 = Backwards
      Servo 2 = Backwards
}
Case (stick left)
{
      Servo 1 = Backwards
      Servo 2 = Forward
}
Case (stick right)
{
      Servo 1 = Forward
      Servo 2 = Backwards
}

Title: Re: RC radio help
Post by: izaktj on September 19, 2009, 03:28:24 PM

Here is the video
RC mixing (http://www.youtube.com/watch?v=gDoD5hOUtZE#)