Modulated 38KHz signal for IR sensor

Hi to everybody. This's my first post

It's not just a problem linked to Arduino, but i asked for help along this forum due to the use of Arduino Uno for the question. I've a common IR LED, an IR receiver Sharp GP1UX 71x with a Band Pass Filter on 38 KHz.

In order to generate a modulated 38KHz signal without the use of a microcontroller unit, i used a NE555 with two resistence (820KOhm and 82KOhm) and a capacitor (22pF), all in Astabile setting. The IR LED was then linked to the 555's OUT.

The receiver output at pin 2 of Arduino Uno board. The code very simple:

void setup() {
  pinMode(2,INPUT);
  Serial.begin(9600);
}

void loop() {
  Serial.println(digitalRead(2));
}

As the datasheet states, without any IR signals, the pin 2 in LOW and the serial monitor prints 1. If i use a common tv remote controller, some changing in the serial string of bits happens (i don't care the secific codes). But if I point the IR LED linked to the NE555 toward the receiver, nothing happens. The out of the GP1UX remains in HIGH state when it would have been in 0 level. Any idea about the reasons or any idea how to solve it?

Thank's a lot.

Page 3, Section 7), Note 1: The duty cycle must be 40% or less. Your continuous/uninterrupted signal gets ignored as most IR receivers are designed to do.

If you want an IR receiver that will not reject a continuous signal use Vishay part TSSP4038 or TSSP58038. These are designed for "light barrier systems" and that appears to be what you're trying to create.

Many IR receivers output HIGH when idle (nothing being received) and LOW when receiving a modulated IR signal.

This would explain why you are getting 1 on the serial connection. If you are getting 0 out on serial when point the IR LED then that is correct, in which case there is not problem with your circuit.

The previous poster is most likely correct - but if you add a second 555 to enable/disable your existing 555 - say 1000 uSecs ON and 1000 uSecs OFF, you may get a better result/performance. If that fails then the Vishay receivers mentioned in the previous post are better for this application.

PS in the above HIGH=5V or 1 and LOW=0V or 0 (I am not sure this is the same as in your original post?)

Hi, having the same issue and this topic is exactly about it I would like to ask in addition if the

TSSP4038 has an advantage in power consumption in comparison to the TSSP4038 which is used here: http://www.pcbheaven.com/circuitpages/Long_Range_IR_Beam_Break_Detector/

If you want an IR receiver that will not reject a continuous signal use Vishay part TSSP4038 or TSSP58038. These are designed for "light barrier systems" and that appears to be what you're trying to create.

So is the 4038 working without any other ICs like 4017, just connected with an Arduino?

7+ year old thread. You could have started a new one.

TSSP/TSOP only has to do with internal gain control of the 3-pin receiver.

The TSSPxx38 is optimised for continuous 38kHz signals, the TSOPxx38 for intermittent (remote control) 38kHz signals.

Both have the same current draw, and both output a LOW when an 38kHz signal is present. Both can be connected directly to an Arduino pin.

The transmit LED is of course using less (average) power with an an intermittent 38kHz signal.

If you use the beam-break for an alarm system, then you could get away with intermittent operation. Sports timers must react faster (no gaps), so might need a continuous carrier.

Use the search field on top of this page to find previous beam break projects. Like this one. Leo..