R/C control help

[mgolu24]

Can any body explaim me the RC control chanels? can i have 4 chanels on the transmiter and 6 on the reciever or any combinations? Please explain me what do these chanels do? (i have a picture what they do but please explain fully) THANKS

[Gopher]

Each channel is like a single control line and can control one attribute of your car, such as the throttle or the steering. As long as your transmitter has more channels than your reciever, then it will work in theory, though you need a matched set of crystals, because the crystals define the frequency they communicate at.  Never actually made a custom r/c device before, so I can't be more specific than that.

[mgolu24]

Thanks. So for throtle i need one chanel for revers i need one chanel and i need one for left and one for right? so i need minimum 4 chanels for my robot to go in all directions. and where the chanel goes out of the reciver i bend the wires to the, let say a dc motor, and when i press the correct chanel button it lets the electricity trough the chanel to the motor and the motor spins?

[Admin]

a channel is just like a button.

for each actuator, it needs a button. button A for motor A, button B for flame thrower B. yeap, you guessed right.

so if your transmitter has 6 channels, it can operate at least 6 different things.

there are tricks to multiplex, so a 6 channel controller could control like 20 servos independently, but that would probably be too much detail for what you want to do . . .

[mgolu24]

there are tricks to multiplex, so a 6 channel controller could control like 20 servos independently, but that would probably be too much detail for what you want to do . . .

no, no indeed please tell me sumthing about it...

[Admin]

ok ok . . . remember how in fighting video games, like mortal combat or streetfighter, if you push a combination of buttons you can do crazy moves? this is how they used a limited number of buttons for unlimited actions.

basically you hook up your reciever to a microcontroller, and the microcontroller processes the buttons according to your program, then outputs a set of actions in that manner.

if i was to make a remote controlled biped, i would use that method . . .

up up down left down up! take that!

you could also do something similar with hardwired electronics.

and lastly, one channel can control multiple servos at the same time, if you dont mind each doing the exact same action . . . just have them share the same signal line . . .

[mgolu24]

ok, so i when i was junger i was interested in microcontrolers. i think i know you have to have some programator whitc you hook up to you pc then u insert the microcontroler in the programator and program it whit qbasic, isnt that right? and when you program it you yust hook it up whit your robot and it does the action

[Admin]

microcontroller tutorial

The language, and whether you need a programmer or not, is dependent on the controller. But yea, thats about right.

[mgolu24]

i thank you for your help and time, and btw you have a really nice website whit many tutorials, excelent for beginner but also for profi's

thnx

[mgolu24]

after more researching i found out that i need(or can) have servo motors. i asked a man who understeands robots and all that stuff, and he sayed that i would need to have servomotors and microswitchers. so when i would press up the servo would rotate and turon on/off the micro switch and the motor would/wouldnt get power and would/wouldnt spin. so im asking, can i connect the motor directly to the reciever? or do i need servo motors and microswhitchers? or is this servo and mikroswitcher thing just like the microcontroler thing, so you mix a combination of buttons?

the servo/switcher thing http://www.borberobota.com/galerija/sezona3/057.jpg

[Admin]

i would need to have servomotors

Servos arent necessary, but recommended. They are easier to work with than plain motors . . .

can i connect the motor directly to the reciever?

Yes, servos connect directly to RC recievers. The microswitch you wanted would just be an on/off switch between the reciever and servo. You dont need a microswitch for it to work unless that is required for your application.

[dunk]

hey mgolu24,
so i'm not sure if you have worked out all the details here or not. (excuse me if you know this allready.)

traditional RC receivers give out a PWM signal (Pulse Width Modulation). the position a servo sits at depends on how wide the pulse is.
explained here: http://www.societyofrobots.com/actuators_servos.shtml
so if you want to controll DC motors from a RC receiver you have a few options:

1. like you said, have the servo turn and push a little switch that in turn switches on the motor. with enough switches you could drive your bot round on 2 channels. one channel for the left and and one for the right wheels, "tank steering" style.
with each servo in the forward position it would push switches that would connect the motor to power in the "forward" direction.
in the center position no switches would be closed so the motor stops.
in the backward position again 2 switches would be pushed closed, this time with the opposite polarity to forwards direction.

2. use a PWM motor controller. these plug in to your controller instead of servos and controll DC motors.
you can buy these from most RC model shops. i don't know much about them. try asking on a RC forum if you need to know more.

3. modify your servo for continuous rotation. http://www.societyofrobots.com/actuators_modifyservo.shtml and actually use the servo as your drive motor. (only good for small bots but probably the easiest option.)

dunk.

[mgolu24]

1. like you said, have the servo turn and push a little switch that in turn switches on the motor. with enough switches you could drive your bot round on 2 channels. one channel for the left and and one for the right wheels, "tank steering" style.
with each servo in the forward position it would push switches that would connect the motor to power in the "forward" direction.
in the center position no switches would be closed so the motor stops.
in the backward position again 2 switches would be pushed closed, this time with the opposite polarity to forwards direction.

thats exactly what im talking about, i found out i need to do that cause the dc motors have another voltage and doesnt uses the same current

[Handmixer.com]

Instead of using twice as many actuators as required, you could just use a pnp transistor for each motor. Just make sure you heatsink them! I tried a photovore with two half h-drives, one per motor, and all the transistors blew. I burnt a finger on it.

[Admin]

I burnt a finger on it

haha yea i burnt my finger on a mosfet trying to make an H-bridge . . . it was so hot that my fingerprint got burned into the aluminum permanently . . . lets not talk about the finger side of it . . . i got a pic of the mosfet somewhere . . .

[mgolu24]

thats what i'm gonna make http://www.borberobota.com/galerija/sezona3/057.jpg