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[on:]

I have been wanting to make my own airplane (rc ofcourse) and automate more things around the house through RF with servos or dc motors but I have always found the lack of information on it to be a blunder so I gave up for the time being. I finally decided to take some courage and give it a go but decided to ask on here for guidance before I begin.


What or where can I learn what is needed and how it works to control a servo or dc motor using a RF remote control?
Do you have any common remotes you use that you would recommend that aren't expensive (I dont want to spend too much so ~20$ would be my range)

Also, I am not super duper familiar with torques in servo motor so when buying a servo how do I know which servo will provide enough torque to turn a door handle or how much torque I need to turn a door handle? Any sites you recommend for servos?

Thanks a ton! I am reading a book on electronics, "Electronics for inventors."

[Reply #1 on:]

twirap
I can't help you out with the torque calculation. But I know about RC.
RC is easier in real life then explained in writing. When you buy a set you have 3 components
1) the rc sender (transmitter)
2) the rc receiver
3) the crystal
The sender comes in many shapes but from a RC point of view there is the number of channels which is important.
You can probably do smart things with the channels but from a starter point of view read channels as follows: 1 channel = 1 servo or 1 arduino pin = 1 remote controlled number (using pulseIn)
The receiver is made for servo's. So you can plug in your servo directly in the receiver and the servo will move as controlled by you sender. If you connect the PWM pin to a arduino pin you can read the pwm value and ....(basically do what you need it to do)
Don't forget that you need to power the receiver or nothing will work. For each channel there is a 3 pin connector (the one that fits your servo) and there iis one extra where you need to apply + and - on the same pins your servo needs + and -. If there are more they probably work but your sender will not send signals.
In a good receiver you can not plug in the servo the wrong way; this way you know where to apply + and -.

The crystal decides on the frequency you play with. If you need multiple sender receiver pairs you will have to use different crystals.
That's all that is to it (for the start).
Best regards
Jantje

[Reply #2 on:]

rcarduino.blogspot.com

http://rcarduino.blogspot.com/2012/01/how-to-read-rc-receiver-with.html

http://rcarduino.blogspot.com/2012/04/how-to-read-multiple-rc-channels-draft.html

http://rcarduino.blogspot.com/2012/01/can-i-control-more-than-x-servos-with.html

Should get you started

Duane B

rcarduino.blogspot.com

[Reply #3 on:]

twirap
I can't help you out with the torque calculation. But I know about RC.
RC is easier in real life then explained in writing. When you buy a set you have 3 components
1) the rc sender (transmitter)
2) the rc receiver
3) the crystal
The sender comes in many shapes but from a RC point of view there is the number of channels which is important.
You can probably do smart things with the channels but from a starter point of view read channels as follows: 1 channel = 1 servo or 1 arduino pin = 1 remote controlled number (using pulseIn)
The receiver is made for servo's. So you can plug in your servo directly in the receiver and the servo will move as controlled by you sender. If you connect the PWM pin to a arduino pin you can read the pwm value and ....(basically do what you need it to do)
Don't forget that you need to power the receiver or nothing will work. For each channel there is a 3 pin connector (the one that fits your servo) and there iis one extra where you need to apply + and - on the same pins your servo needs + and -. If there are more they probably work but your sender will not send signals.
In a good receiver you can not plug in the servo the wrong way; this way you know where to apply + and -.

The crystal decides on the frequency you play with. If you need multiple sender receiver pairs you will have to use different crystals.
That's all that is to it (for the start).
Best regards
Jantje

Thank you both of you for the help! I will post details and question updating this thread as I go. Jantje with the crystal information you provide it makes sense to me....... I am going to give rc lawn mower a try or perhaps an rc plane....whichever is easier for a first rc project.

[Reply #4 on:]

Thank you both of you for the help! I will post details and question updating this thread as I go. Jantje with the crystal information you provide it makes sense to me....... I am going to give rc lawn mower a try or perhaps an rc plane....whichever is easier for a first rc project.

You don't mention in your profile where you live (hint, hint - it will help us help you better in the future), but something you should check out are the various laws/rules for your country and/or locality in regards to R/C transmitters and receivers.

For instance, from what I understand - in the United States you can't use an R/C aircraft transmitter/receiver combo for anything but an R/C aircraft; such transmitters and receivers have specific frequencies they operate on. Furthermore, for aircraft transmitters and receivers, an individual can't legally change out the crystals of the transmitter and receiver (they must send it back to the manufacturer for that). It has something to do with proper tuning after they are switched out, to decrease issues with cross-frequency interference and such (I think). You also can't remove or change the antenna flag, either (it must match the crystal in the kit).

That said - I don't know how much or well such laws/rules are enforced, nor what the fines are. Again, this is just based on what I read up on regarding FM transmitters and receivers (because I was researching such after finding a nice 4 channel Airtronics transmitter, and I needed a receiver and crystal to match). Furthermore, I don't know how this effects the newer spread-spectrum 2.4 GHz systems.

Nor do I know how any of this applies outside of the United States - just something you should keep in mind, if you plan on using any FM system (which admittedly are fairly old and "obsolete" by some standards)...

[Reply #5 on:]

As cr0sh stated, in the USA RC controllers for model aircraft have more restrictive rules.  However, for many other parts of the RF spectrum unlicenced use is allowed if the transmitters have a limited range or power (the limit differs for each band, here's a direct link to the FCC bulletin containing all the gory details).  Basically though, if you use a RC controller intended for a ground or water vehicle or a custom built FM transmitter with a usable range under 200 ft on an RC lawnmower, it should be OK.