Infrared Receiver Module

[Thomas Karpiniec]

Hello everyone,

I'm trying to use a 3-pin IR Receiver Module (numbers on back: 3834, 73A),
for detecting infrared frequencies between 30 and 40 Khz. I'm having a bit
of trouble operating it. I have seen somewhere a schematic that had external
components around it, but I don't know what these are. At the moment I'm
running it stand-alone as follows:

Pin 1 - Signal (to LED)
Pin 2 - Ground
Pin 3 - +5V

It seems to work at least a little bit. I have an LED hooked up, and as soon
as I apply power, it turns on partially, whether I have the other end
connected to the +5V or ground line (a voltage somewhere between the two
rails from pin 1 then I presume?). When I get a standard VCR remote control
and press a button, the LED wavers a bit. It's too fast to tell exactly
whether it's flashing brighter, or dimming, but it certainly changes.

I was wondering if anyone could enlighten me on what it is doing. The
application is a mini-sumo robot, which needs object detection. I want to
use one of these modules as the receiver.

Thanks for any help,

-- Thomas

 

[Joe]

"Thomas Karpiniec" <tkarpiniec@iprimus.com.au> wrote in message
news:3f68450a$1_1@news.iprimus.com.au...

Hello everyone,

I'm trying to use a 3-pin IR Receiver Module (numbers on back: 3834, 73A),
for detecting infrared frequencies between 30 and 40 Khz. I'm having a bit
of trouble operating it. I have seen somewhere a schematic that had
external
components around it, but I don't know what these are. At the moment I'm
running it stand-alone as follows:

Pin 1 - Signal (to LED)
Pin 2 - Ground
Pin 3 - +5V

It seems to work at least a little bit. I have an LED hooked up, and as
soon
as I apply power, it turns on partially, whether I have the other end
connected to the +5V or ground line (a voltage somewhere between the two
rails from pin 1 then I presume?). When I get a standard VCR remote
control
and press a button, the LED wavers a bit. It's too fast to tell exactly
whether it's flashing brighter, or dimming, but it certainly changes.

I was wondering if anyone could enlighten me on what it is doing. The
application is a mini-sumo robot, which needs object detection. I want to
use one of these modules as the receiver.

Thanks for any help,

-- Thomas

Hi Thomas,

I am no expert, but I just went thru a few months of hobbying around with a
TSOP1238 IR receiver and transmitter myself.

What I learned is that when the (close to )correct frequency IR hits the
receiver, the receiver output goes low. The receiver strips off the carrier
frequency which can be 36,38, or 40khz. Sounds like yours might be 38khz
(just by the 3834 designation you mentioned). I don't know if you have an
oscope, but i dont. I was using a piezo buzzer a voltmeter, and a red LED
to 'tell' me what was going on. You can also use the LED by connecting the
anode to the plus 5V (using a 270ohm resistor in series). Then connect the
cathode(negative side) of the LED to the output (pin 1) of the IR receiver.
Then apply the IR signal. If the LED lights, then you know your receiver is
active low and you can drive a 555 as a oneshot directly from it.

My application was not for robotics and I am sure you need to be careful
about where the IR source is in relation to the receiver so you don't get
false triggers. You can also post the schematic of the circuit you mentioned
to alt.binaries.schematics.electronics
and then reference it so others may be able to help you.
If you scan it, try to make it into a .gif file tho so it is not too big
(maybe under 100k is good).

Also try a web search for "IR receiver" and "IR transmitter" using google.
There's lots of info on the web, especially for robotics applications.

hth,
Joe

 

[Colubris]

"Joe" <nuisancewildlife@nospamearthlink.net> wrote in message news:<L42ab.28238$NM1.2156@newsread2.news.atl.earthlink.net>...

"Thomas Karpiniec" <tkarpiniec@iprimus.com.au> wrote in message
news:3f68450a$1_1@news.iprimus.com.au...
Hello everyone,

I'm trying to use a 3-pin IR Receiver Module (numbers on back: 3834, 73A),
for detecting infrared frequencies between 30 and 40 Khz. I'm having a bit
of trouble operating it. I have seen somewhere a schematic that had
external
components around it, but I don't know what these are. At the moment I'm
running it stand-alone as follows:

Pin 1 - Signal (to LED)
Pin 2 - Ground
Pin 3 - +5V

It seems to work at least a little bit. I have an LED hooked up, and as
soon
as I apply power, it turns on partially, whether I have the other end
connected to the +5V or ground line (a voltage somewhere between the two
rails from pin 1 then I presume?). When I get a standard VCR remote
control
and press a button, the LED wavers a bit. It's too fast to tell exactly
whether it's flashing brighter, or dimming, but it certainly changes.

I was wondering if anyone could enlighten me on what it is doing. The
application is a mini-sumo robot, which needs object detection. I want to
use one of these modules as the receiver.

Thanks for any help,

-- Thomas

Hi Thomas,

I am no expert, but I just went thru a few months of hobbying around with a
TSOP1238 IR receiver and transmitter myself.

What I learned is that when the (close to )correct frequency IR hits the
receiver, the receiver output goes low. The receiver strips off the carrier
frequency which can be 36,38, or 40khz. Sounds like yours might be 38khz
(just by the 3834 designation you mentioned). I don't know if you have an
oscope, but i dont. I was using a piezo buzzer a voltmeter, and a red LED
to 'tell' me what was going on. You can also use the LED by connecting the
anode to the plus 5V (using a 270ohm resistor in series). Then connect the
cathode(negative side) of the LED to the output (pin 1) of the IR receiver.
Then apply the IR signal. If the LED lights, then you know your receiver is
active low and you can drive a 555 as a oneshot directly from it.

My application was not for robotics and I am sure you need to be careful
about where the IR source is in relation to the receiver so you don't get
false triggers. You can also post the schematic of the circuit you mentioned
to alt.binaries.schematics.electronics
and then reference it so others may be able to help you.
If you scan it, try to make it into a .gif file tho so it is not too big
(maybe under 100k is good).

Also try a web search for "IR receiver" and "IR transmitter" using google.
There's lots of info on the web, especially for robotics applications.

hth,
Joe

Another tip to remember about many of the IR detector modules is that
they usually have some sort of Automatic Gain Control (AGC) - the
effect being that the modules can not be used to detect a contiuously
ON carrier.

Arch

 

[Anand Dhuru]

Hi Thomas,

I'm trying to use a 3-pin IR Receiver Module (numbers on back: 3834, 73A),
for detecting infrared frequencies between 30 and 40 Khz. I'm having a bit
of trouble operating it. I have seen somewhere a schematic that had external
components around it, but I don't know what these are. At the moment I'm
running it stand-alone as follows:

Yes; a resistor of about 100 ohms between the +5 volts of the supply
and the +5 of the module, with a 10uF cap. between the + and ground of
the module helps a lot.

Pin 1 - Signal (to LED)
Pin 2 - Ground
Pin 3 - +5V

It seems to work at least a little bit. I have an LED hooked up, and as soon
as I apply power, it turns on partially, whether I have the other end
connected to the +5V or ground line (a voltage somewhere between the two
rails from pin 1 then I presume?). When I get a standard VCR remote control

No; this is the noise that the module is generating / catching; the
above components should give you a steady '1' on the output in the
absence of a modulated IR signal.

and press a button, the LED wavers a bit. It's too fast to tell exactly
whether it's flashing brighter, or dimming, but it certainly changes.

Now, the output LED (if connected between +5 and output, since the
output is active low) will be lit only when you point an IR signal
from the remote onto your module.

There is a simple way of actually seeing the IR signal without an
oscilloscope; just feed the output of your module into the sound card
in your PC, and save the sinal as a .wav file. Then, open it into any
sound editor (like GoldWave, downloadable free) and keep zooming till
you can see the individual bits of the original signal. Helps in
debuggging like nothing else can!

Regards,

Anand Dhuru

I was wondering if anyone could enlighten me on what it is doing. The
application is a mini-sumo robot, which needs object detection. I want to
use one of these modules as the receiver.

Thanks for any help,

-- Thomas

 

[Anthony Fremont]

Thomas Karpiniec wrote:

Hello everyone,

I'm trying to use a 3-pin IR Receiver Module (numbers on back: 3834,
73A), for detecting infrared frequencies between 30 and 40 Khz. I'm
having a bit of trouble operating it. I have seen somewhere a
schematic that had external components around it, but I don't know
what these are. At the moment I'm running it stand-alone as follows:

Pin 1 - Signal (to LED)
Pin 2 - Ground
Pin 3 - +5V

If the IR receiver is in a metal can, don't forget to ground the can.
It makes a major difference in the amount of noise output from the
detector. It's the difference between a clean, usable signal and a
bunch of worthless noise. You aparently have a high level of noise if
the LED is lighting in either orientation. The output pin of the
detector is normally at a high level (5V), it goes low upon detection of
the proper carrier frequency.