IR Delay

[NivNavick]

Hi,
I am using an IR sensor to detect a ball that send IR pulses (rcj-05).
The sensor works perfectly but when the ball leave the IR sight the IR entered to delay and when the ball enter to the IR sight the sensor doesn't
See the ball for the next few second.
What can cuse this problem?or thats happens in all IR sensors?
My final and most important question is if the problem can be solve by code?

Thank you and have a nice weekend!

[temtronic]

Full moon ? Spilled your coffee ? Odd numbered day of the month ???
Honestly, you have to post a complete, small, compilable program that shows the problem,also include compiler version and PIC type !
No one can help you without this information !

[NivNavick]

There is no code,I saw this by the Scope.
And my question was if thus can be solved by code?

[Ttelmah]

No.
The PIC is not able to predict the future. If the sensor is not sending pulses, then no amount of coding can fix things....

Best Wishes

[NivNavick]

But usually IR sensors have a delay sometimes?
I checked two different types of IR sensors and both
Of them have delay.

P.S.
I am using TSop1240.

Thanks

[temtronic]

I suggest you download the data sheet for the sensors and read all of it.

hine You'll find out it is a 'smart ' sensor not just an IR detector.

Also be aware you must have the correct snesor for your 'ball' transmitter.

I'm assuming you're building a motorized cart to find and /or capture the
ball ???

If so it's an interesting project,tons of similar code already on the net....

[NivNavick]

I'm competing in Robocup Junior Soccer competition and for that I need the ball.

What do you mean by not just IR detector and smart sensor?

thanks!

P.S
I am from software team, not electronic, but eventually my responsibility is
to integrate all the hardware to work together I guess you know what I mean.
The electronic team read the DATA SHEET 100 times and still can't figure out what is the problem.

[temtronic]

A 'simple' sensor would only detect, usually in an analog form the object of interest, in this case IR energy, however this is what I call a 'smart' sensor', loaded with electronics to 'filter' the signal.

Quoting from the datasheet....
... The circuit of the TSOP12.. is designed so that unexpected
output pulses due to noise or disturbance signals
are avoided. A bandpass filter, an integrator
stage and an automatic gain control are used to suppress
such disturbances.

... The distinguishing mark between data signal and disturbance
signal are carrier frequency, burst length
and duty cycle.
The data signal should fulfill the following conditions:
• Carrier frequency should be close to center frequency
of the bandpass (e.g. 38 kHz).
• Burst length should be 10 cycles/burst or longer.
• After each burst which is between 10 cycles and 70
cycles a gap time of at least 14 cycles is necessary.
• For each burst which is longer than 1.8 ms a corresponding
gap time is necessary at some time in the
data stream. This gap time should be at least 4 times
longer than the burst.
...
Obviously you can develop PIC code to use this sensor, as it's very similar what others have already done.

[Douglas Kennedy]

There is a whole lot of IR in the environment. Fluorescent lights especially.
IR signaling is modulated and filtered to help contrast the signal against the background. Background IR noise wouldn't be modulated so a modulated signal can be teased out of the noise. IR remote controls go to some length in filtering and coding to screen out environmental noise that could trigger things.

[NivNavick]

[FvM]

You didn't tell the sensor manufacturer and type. As far as I understand, it's a common 38 kHz remote control receiver. None of the sensors I ever saw have a "few second" response time respectively delay.

Either you managed to design a weird circuit or a strange software.

P.S.: I found the sensor specification in a later post.

I see that TSOP1240 is also listed as possible detector for the RCJ-05 modulation. In so far there should be no general technical issue.

But how are you using the sensor? I guess you intend to determine the ball direction. So you have to restrict the sensor's angle of view. Are you sure, that you have sufficient IR signal on the sensor when you see the delay?

For an effective position tracking, one would prefer sensors that give an intensity information rather than an on/off detctor like the TSOP1240. I understand, that the trapezoidal waveform is used to convert intensity into pulse width. But it's a rather rough method.

[NivNavick]

maybe the electronic circle cause it?

[NivNavick]

What IR sensor are you suggesting?

[temtronic]

Niv...
you're not giving us enough information!
Where's your PIC code and are your sensors' the correct type? ie: same frequency as the ball's IR transmitters?

[NivNavick]