2

Author Topic: IR Remot controle  (Read 4158 times)

0 Members and 1 Guest are viewing this topic.

Offline 555 timer chip guyTopic starter

  • Full Member
  • ***
  • Posts: 105
  • Helpful? 0
IR Remot controle
« on: March 15, 2007, 05:01:15 PM »
I am having some trouble with making a 38 KHz transmiter I am using a 555 unstable oscillator circuit but for some reason my 38 KHz receiver is not picking up the signal but works fine with a standard TV remote. Dose any one have a suggestions.

Offline dunk

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 1,086
  • Helpful? 21
Re: IR Remot controle
« Reply #1 on: March 16, 2007, 06:07:49 AM »
many ccd cameras can see infared light.
find a camera that can see your tv remote and compair the brightness of your circuit.

dunk.

Offline sdk32285

  • Supreme Robot
  • *****
  • Posts: 418
  • Helpful? 0
Re: IR Remot controle
« Reply #2 on: March 16, 2007, 08:05:00 AM »
A lot of time on higher end cameras there is an IR filter that can be removed.
Robots for Roboticists Blog - http://robotsforroboticists.com/

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: IR Remot control
« Reply #3 on: March 16, 2007, 09:10:46 AM »
You need an oscilloscope to view the waveform of the IR emitter circuit.  Look for a Radio Shake ProbeScope -

    http://www.linuxtoys.org/pscope/pscope.html

or do a web search on serial port / USB oscilloscopes.  If you are building your own circuits, you won't use an oscilloscope too often, but when you need it, there is no better tool for sorting out waveform problems.
Surveyor Corporation
  www.surveyor.com

Offline 555 timer chip guyTopic starter

  • Full Member
  • ***
  • Posts: 105
  • Helpful? 0
Re: IR Remot control
« Reply #4 on: March 16, 2007, 08:12:32 PM »
You need an oscilloscope to view the waveform of the IR emitter circuit.  Look for a Radio Shake ProbeScope -

    http://www.linuxtoys.org/pscope/pscope.html

or do a web search on serial port / USB oscilloscopes.  If you are building your own circuits, you won't use an oscilloscope too often, but when you need it, there is no better tool for sorting out waveform problems.
I have an oscilloscope but it can only read up to 5 KHz and the only oscilloscope that I fond that can read 38 KHz is $400.

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: IR Remot controle
« Reply #5 on: March 16, 2007, 09:26:32 PM »
You can sometimes find the ProbeScope on eBay for around $70.  Also, there seems to be a US distributor for the product, which is actually called osziFOX -

    http://www.biotechproducts.com/wittig-oszifox.html

According to what I've seen, this scope can sample up to 2MHz.

I have a Velleman HPS40 scope that cost about $200.  It is not the great scope, but it has paid for itself in troubleshooting some problems, including some 38kHz IR circuits.
Surveyor Corporation
  www.surveyor.com

Offline 555 timer chip guyTopic starter

  • Full Member
  • ***
  • Posts: 105
  • Helpful? 0
Re: IR Remot controle
« Reply #6 on: March 18, 2007, 10:22:11 AM »
You can sometimes find the ProbeScope on eBay for around $70.  Also, there seems to be a US distributor for the product, which is actually called osziFOX -

    http://www.biotechproducts.com/wittig-oszifox.html

According to what I've seen, this scope can sample up to 2MHz.

I have a Velleman HPS40 scope that cost about $200.  It is not the great scope, but it has paid for itself in troubleshooting some problems, including some 38kHz IR circuits.

I was thinking maybe the receiver receives pulse with modulation.

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: IR Remot controle
« Reply #7 on: March 18, 2007, 12:22:02 PM »
What IR receiver are you using ?
Surveyor Corporation
  www.surveyor.com

Offline 555 timer chip guyTopic starter

  • Full Member
  • ***
  • Posts: 105
  • Helpful? 0
Re: IR Remot controle
« Reply #8 on: March 18, 2007, 05:31:18 PM »
What IR receiver are you using ?
A 38 KHz receiver from radio shack.

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: IR Remot controle
« Reply #9 on: March 18, 2007, 06:30:43 PM »
Well ... if the IR receiver is indicating a received signal from your TV remote, it probably is working fine.  The remote sends out a bit pattern by turning on and off a 38kHz IR transmitter, so the receiver will show a HIGH output when it is receiving the 38kHz signal, and LOW when it isn't.  The filtering on the receiver isn't that tight, so a 36kHz signal or 40kHz signal will still trigger a HIGH.  From your description, it seems that your transmitter isn't producing anywhere close to 38kHz.
Surveyor Corporation
  www.surveyor.com

Offline 555 timer chip guyTopic starter

  • Full Member
  • ***
  • Posts: 105
  • Helpful? 0
Re: IR Remot controle
« Reply #10 on: March 19, 2007, 02:21:22 PM »
Well ... if the IR receiver is indicating a received signal from your TV remote, it probably is working fine.  The remote sends out a bit pattern by turning on and off a 38kHz IR transmitter, so the receiver will show a HIGH output when it is receiving the 38kHz signal, and LOW when it isn't.  The filtering on the receiver isn't that tight, so a 36kHz signal or 40kHz signal will still trigger a HIGH.  From your description, it seems that your transmitter isn't producing anywhere close to 38kHz.

Please explain this bit pattern is it possible to create this with a 555 ustable and a monostable oscillator circuit if not please tell me how.  :)

Offline hgordon

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 373
  • Helpful? 7
Re: IR Remot controle
« Reply #11 on: March 19, 2007, 03:37:29 PM »
I use the processor to generate bit patterns that control the IR emitter from software, so I can't tell you how to do this with a 555.

Surveyor Corporation
  www.surveyor.com

Offline 555 timer chip guyTopic starter

  • Full Member
  • ***
  • Posts: 105
  • Helpful? 0
Re: IR Remot controle
« Reply #12 on: March 20, 2007, 05:23:45 PM »
Do you know of any other ways.

Offline dunk

  • Expert Roboticist
  • Supreme Robot
  • *****
  • Posts: 1,086
  • Helpful? 21
Re: IR Remot controle
« Reply #13 on: March 21, 2007, 03:29:11 PM »
there's a few projects here that might be of help:
http://users.frii.com/dlc/robotics/projects/botproj.htm

dunk.

 


Get Your Ad Here