Looking for components to make an IR controlled robot

[Robert Hill]

Hi all,

I have already built a remote control car using RF communication but because of the cheap RF transmitter and receiver I used the range isn't very good. It used L293D motor driving ICs and a HT12E/D pair along with the RF components. I had two motors running bi directional to get turn left, turn right, forwards and backwards each controlled by one of the 4 channels on the encoder/decoder ICs.

I'd like to build another remote control car but this time use Infrared communication to see if I can get better range. Ideally I'd use the same motor drivers. I understand that there is an infrared compatible version of the encoder (HT12A) but I can't find a supplier online or else it seems very expensive on Ebay.

So, I suppose my question is:

Can someone recommend me some ICs which will allow 4 channel communication using IR transmitters and receivers which won't cost loads?

Thanks in advance.

 

[73's de Edd]

Sir Robert Hill . . . . .

If you are not liking RF intercommunication . . . .I.R. interfacing should be an abysmal failure, in comparison, with a "moving target" consideration.

You just need either better antenna interfacing on the T-R units OR just units with a bit more RF output on the transmitter and better receiver circuitry.

You never gave us your present unit to evaluate.


73's de Edd

 

[Robert Hill]

Hi, thanks for your reply,

The Rf units I am using are these: http://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=302_312&products_id=2264

The reason I was thinking about infrared is that my son has one of these: https://www.amazon.co.uk/VTech-Toot-Toot-Drivers-Remote-Control/dp/B00VWL3MWY
Which seems to use infrared to communicate between the car and controller.

What do you think?

 

[Sunnysky]

Range depends on Tx / Rx orientation, gain Tx Power, path loss, interference from reflections, etc and data rate.

What range and data rate?
IR Remote TV controllers can be made to go 30 m easily line of sight, but not mobile . For helicopters it works better as the sensors point downwards but cars can be in the opposite direction and AGC can usually track fast enough.

Wireless example needs more power.

 

[73's de Edd]

Sir Robert Hill . . . . .

Taking your info that you supplied . . .your kiddo's toy only moves forward and backwards . . .with no
turns to figure out in having an IR signal to track.
For a further surprise, take that toy unit from the house and try to use it in the sunlit outdoors.


Surely your other RF associated unit involves turns, which would be of no concern with RF interfacing.
You just need a more reliable and extended range of the RF pair.
The manufacturers pics were absolutely too small to evaluate the receivers design.

Sooooooooo, now its mo' bigger :

I can now see that the transmitter is being a fixed freq and canned unit.
I can see that the receiver RF portion is using 1 transistor as being a superregenerative receiver.
That technology has been around 86 years . . . . back to initially encompassing a vacuum tube.
For its utter simplicity, it works fine . . . . but its reception performance improves exponentially with a GOOD antenna.

Since I NOW know its operating frequency, I would now suggest a tuned antenna to be used with both the
transmitter and paricularly, the receiver.

I would be thinking of a 1/4 or 5/8 wavelength stub antenna but an associated loading coil wouild also pep it
up additionally, along with needing a bit less overall length.

To save me some keystrokes and custom illustrations use these references and inquire if any questions.

Use large enough wire . . .solid and plastic insulated . . . to hold itself stable vertically on both Rx and Tx versions.
(The loading coil end goes closest to the Rx or Tx board.)

https://arduinodiy.wordpress.com/2015/07/25/coil-loaded-433-mhz-antenna/

https://www.elektor.nl/Uploads/Forum/Posts/How-to-make-a-Air-Cooled-433MHz-antenna.pdf
(Has a SLOW download . . . . . . due to hand cranked processor )


73's de Edd

 

[Robert Hill]

Thanks, I have given it a go and it doesn't seem to improve the range at all. I think I might need to go for a better quality rx/tx pair. Thank you fro your help.

 

[Robert Hill]

Do you think either of the following would give a better result?

http://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=302_312&products_id=2114

or

http://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=302_312&products_id=2753
http://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=302_312&products_id=2752