Radio Control

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smoshier
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Radio Control

Post by smoshier » Mon Nov 26, 2007 7:19 pm

I want to be able to control a robot's actions using a wireless control (like you see with model airplanes). Does anyone know of a good tutorial on how to set up a robot to receive the signal and to sort out what to do?

hakbot
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Post by hakbot » Mon Nov 26, 2007 7:27 pm

Your post is very vague. You give almost no info on your robot so it will be hard to point you in the right direction.

smoshier
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Post by smoshier » Mon Nov 26, 2007 8:59 pm

I have not started building a robot. I would like this information so that when I have the time to build one, I would know the capabilities of this setup.

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jaem
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Post by jaem » Tue Nov 27, 2007 2:39 am

If you want a control similar to airplanes, you'd need something completely different from what I'm suggesting, but for a robot, this could work:

Cypress Semi makes so-called "WirelessUSB" transceivers (as opposed to "Wireless _ USB" which is actually what it sounds like). I haven't tried out the ones I ordered yet, because I've been busy lately, but they look pretty good. The ones I have have a 10m range, although you can get ones with considerably longer range as well, and they operate at up to 62.5kbps. They use an SPI interface to a microcontroller on both ends, so they're pretty simple to control. You can read in the signal strength, change between a multiplicity of channels, etc. The best part is that Cypress gives samples of them - and not just the infuriatingly small ICs, but actual modules with a dual-row header and a built in antenna, crystal, and everything else you need. I can't remember what their samples policy is, but you may be able to get a couple for free. Here's the product page. This is just one idea, and without a better picture of what you're looking for, I can't advise you much, but this may be worth checking into. And hey - if they're free, who's complaining? :P

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slamer
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What kind of radio?

Post by slamer » Tue Nov 27, 2007 9:16 am

There are many ways to send control signals to a robot's drive train using either just straight RC control or by talking to a Micro controller or a computer. It would be helpfull if you would be a little more specific.

For straight RC control. Well these guys have master'd that for just about anything with a range of up to 3000 feet. Check out the RFL forum
http://botleague.net/

If you want to talk to a BASIC Stamp micro controller with a Airplane Radio. That's pretty easy as well with a little programming and wiring.

Here is some PBASIC code for the Parallax Boe Bot that reads the receiver outputs (servo position commands) for just about all of the RC radios...

' ==============================================================================
'
' File......
' Purpose...RC CONTROL OF BOEBOT
'
' {$STAMP BS2}
' {$PBASIC 2.5}
'
' ==============================================================================


' ------------------------------------------------------------------------------
' Program Description
' ------------------------------------------------------------------------------

'Control A boe-bot using 2-Channel R/C

' ------------------------------------------------------------------------------
' Constants
' -------------------------------------------------------------------------------
state CON 1

' ------------------------------------------------------------------------------
' I/O Definitions
' ------------------------------------------------------------------------------
Ch1 PIN 12 ' Elevator channel used to drive forward and backward
Ch2 PIN 13 ' Aileron channel used to steer left and right
L_servo PIN 14 ' Left servo
R_servo PIN 15 ' Right servo
' ------------------------------------------------------------------------------
' Variables
' ------------------------------------------------------------------------------
steer VAR Word
drive VAR Word
R_Target VAR Word
L_Target VAR Word
' -------------
' Program Code|
' -------------
begin:
DO
PULSIN Ch1 , state , drive 'read receiver channel 1
PULSIN Ch2 , state , steer 'read receiver channel 2
R_Target = drive - 750 + steer
L_Target = 750 - drive + steer
PULSOUT L_servo , L_Target 'send signal to left motor
PULSOUT R_servo , R_Target 'send signal to right motor
PAUSE 10
LOOP

***********************************************
Now all you need is a BOE BOT...

http://www.parallax.com/ProductInfo/Rob ... fault.aspx

smoshier
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Post by smoshier » Tue Nov 27, 2007 2:37 pm

Thank you everyone for the information.

hakbot
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Post by hakbot » Fri Nov 30, 2007 2:23 pm

There are many different ways to go about wireless control so thats why I was asking you to tell me more info.

Anyway you can go with something simple like a standard r/c transmitter and use servos and motors. You can buy wireless rs232 modules and couple them with an MCU if you want to go more of a DIY approach but this will take some programming and electronics know how.These modules usually come in 433MHz, 900MHz, and 2.4GHz so you'll have to decide this later on. There is bluetooth. Most new laptops now days have bluetooth built in so this means you will only really need to build a receiver on your bot but again you will need a MCU. You can build a bot that is PC based and use wifi to control it. IR is also another option but this is line of sight. Some of the smaller R/C planes use this due to low weight. There are many tutorials out there but you probably need to decide on what you want to do first.

smoshier
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Post by smoshier » Thu Dec 20, 2007 2:49 pm

I want an option to control using an R/C controller or by using wireless through a computer. I know enough about electronics to do this from scratch.

I plan on doing this one step at a time, eventually having a camera and a robotic arm, but first step is getting the motors controlled by the R/C controller.

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