go_away

Author Topic: remote control  (Read 4526 times)

0 Members and 1 Guest are viewing this topic.

Offline boneyTopic starter

  • Jr. Member
  • **
  • Posts: 16
  • Helpful? 0
remote control
« on: January 10, 2007, 12:51:05 AM »
 :o
I have tried to make a rf remote for my robo base plate.

four keys viz: forward, backward, left and right, produce 4-bit binary codes when pressed.

these codes are applied to the control lines of L293 motor driver IC.

key     codes
         D3  D2  D1  D0
F        0    1    1    0
B        1    0    0    1
L        1    0    1    0
R        0    1    0    1

I want to transmit these codes to the driver IC wirelessly using a RF module.

The problem is that the module i have got transmits data on a single pin and the encoder decodr pair i have used donot produce accurate conversion of the codes onto a single line(pin)

I need help in converting the codes faithfully into a voltage
and transmiting it over the module and then converting the voltage level recieved into a 4-it code accurately.

urgently require suggestions.

Offline JesseWelling

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 707
  • Helpful? 0
  • Only You Can Build A Robot!
Re: remote control
« Reply #1 on: January 10, 2007, 04:13:04 AM »
Is this a rf module like this one:
http://www.sparkfun.com/commerce/product_info.php?products_id=7816

why don't you describe your whole system from key press all the way to motor moveing so we can get a better idea of what is going on.

I'm guessing what you need to do is send the serial command over the TX module, then have that RX module hooked up to your microcontrolers serial port and then have that micro controller output whatever it needs to to get the motors running (whatever this L293 needs....)

sorry i can't help more...i'm tired :-\
« Last Edit: January 10, 2007, 04:18:48 AM by JesseWelling »

Offline boneyTopic starter

  • Jr. Member
  • **
  • Posts: 16
  • Helpful? 0
Re: remote control
« Reply #2 on: January 10, 2007, 10:13:49 AM »
the RF module i'm using is
http://vegakitindia.com/productdetails.asp?ProdID=RF01A315

I donot have a microcontroller on board. And yes i need to convert the binary code to some voltage level ( may be a decimal value) over the TX module.

On recieving this voltage i need to convert it back into the binary code
and apply the code to pin no. 2,7,10 and 15 of the driver IC.
i've attached the data sheet and i'm using the DIP 16 pin version.

actually the stuff works perfectly when i connect the code directly to the driver IC.
its only that i need to make it wireless


Offline JesseWelling

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 707
  • Helpful? 0
  • Only You Can Build A Robot!
Re: remote control
« Reply #3 on: January 10, 2007, 11:32:28 AM »
well....you need a micro controller and then you can send serial signals at 9600bps to that micro controller which will then output to your L293.....I sugest either a PIC (16 or 18 series) or an AVR Atmega (8 or bigger). some thing like this: http://www.sparkfun.com/commerce/product_info.php?products_id=29 will allow you to put all your stuff in one place.
....other than that I don't know of an i/c that will work for you.

Offline Militoy

  • Expert Roboticist
  • Full Member
  • *****
  • Posts: 111
  • Helpful? 0
Re: remote control
« Reply #4 on: January 10, 2007, 01:03:33 PM »
Instead of an analog voltage level, you could generate a different DTMF frequency for each command, using a touchtone keypad. Modulate the transmitted carrier with the tone, and feed the received tone into a DTMF tone decoder, such as an LM567. The circuit shown in the link below could be adapted to feed the digital code you want directly into your motor driver.

http://www.national.com/pf/LM/LM567C.html

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,658
  • Helpful? 169
    • Society of Robots
Re: remote control
« Reply #5 on: January 10, 2007, 06:00:27 PM »
Quote
actually the stuff works perfectly when i connect the code directly to the driver IC.
What do you mean by connecting the code? Are you hard-wiring this? Or doing some type of serial command from your PC?

Im gonna side with JesseWelling on this, if you are really serious about robotics, you should invest in a microcontroller :P

Offline Militoy

  • Expert Roboticist
  • Full Member
  • *****
  • Posts: 111
  • Helpful? 0
Re: remote control
« Reply #6 on: January 10, 2007, 06:56:59 PM »
Quote
Im gonna side with JesseWelling on this, if you are really serious about robotics, you should invest in a microcontroller

I wasn't trying to take sides against Jesse with my suggestion - Having the "brains" of the robot on-board and independent should certainly be the ultimate goal of anyone building a "serious" robot - but simple R/C robots also present some challenges; and I wouldn't think to second guess the goals of someone else's project. It appears to me that the immediate problem boney is facing is how to reliably transmit 4 commands via an FM RF link to his platform, and translate into a 4-bit parallel data word. IMHO, it would be easier to achieve that goal using low-$ dual tone modulation, than by trying to translate an analog voltage level via RF. As far as the micro goes - sometimes you have to learn to walk, before you can run!

Offline Admin

  • Administrator
  • Supreme Robot
  • *****
  • Posts: 11,658
  • Helpful? 169
    • Society of Robots
Re: remote control
« Reply #7 on: January 11, 2007, 12:43:50 PM »
Quote
Quote
Quote
Im gonna side with JesseWelling on this, if you are really serious about robotics, you should invest in a microcontroller

I wasn't trying to take sides against Jesse with my suggestion

oops ok I didnt mean that you were opposing Jesse . . . this was independent of what you said
really bad wording on my part . . .  :P

I just meant I agree with Jesse to go for a microcontroller, if he wanted PC control.

Boney, if you just want RC and have about $150 to spend, Id recommend getting a hobby RC controller and receiver with a dual motor driver capable of receiving RC signals. Ill give you links if you want . . .

Offline dunk

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 1,086
  • Helpful? 21
Re: remote control
« Reply #8 on: January 11, 2007, 02:36:54 PM »
so i know a microcontroller would add a lot of functionality but if you only want a simple remote controll they are not the simplest option.

for my first remote controll project i used encoders from the Holtek ht12 range.
http://www.holtek.com.tw/english/products/remote_1.htm

they are really easy to use. rather than explain it myself, here's a link:
http://www.multyremotes.com/four-channel-ASK-remote.htm

see? easy peasy.

dunk.

Offline JesseWelling

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 707
  • Helpful? 0
  • Only You Can Build A Robot!
Re: remote control
« Reply #9 on: January 12, 2007, 09:52:29 PM »
....bleh....i'd rather program  ;D

 


Get Your Ad Here