infrared remote basics..

[beyondH]

hellow experts,,
I want to make a simple remote having some buttons which can on and off some leds and relays using infrared...
how do start with, I don't know basics of infrared communication...(transfer of data and all...)
kindly guide me for the same..

 

[debjit625]

To do that you need to have knowledge about microcontrollers and programming.It will be very easy to implement such a device using microcontrollers.

I don't know basics of infrared communication

It use serial communication to transmit data.
If you are building your own device i.e.. both the IR transmitter and reciver,you may use any IR communication protocol but if you already have an IR transmitter ,that you want to use in your project ,then you have to find out its protocol,its not that hard but you will need a logic analyzer to do that.

Good Luck

 

[beyondH]

hmm,, thanks for your reply..
but what i want is...I have a remote with a few buttons that can switch on and off some of the relays and leds on other board using infrared...i.e first button for led, second for relay and so on..
i think ki this kind of circuit can be made without using controller too...i.e. using a clock generator like 555 or any other...
I want to do it using basics first then switch over to controller side..

 

[Pjdd]

An IR remote control with limited functions can be made without using a general-purpose microcontroller, e.g., the Holtek HT12A IC for encoding at the transmitter and the HT12D for decoding at the receiver. These ICs have provision for four different functions.

A remote control system can be divided into two parts. The first one is the carrier. It's not enough to project a beam of IR light because there are many other sources of infrared radiation including sunlight, and the receiver will have no way of knowing which is which. The transmitter has to be pulsed at a certain rate that the receiver can recognize. The most common standard frequency is 38kHz, others are 36kHz, 40kHz, 56kHz, etc. Even that is not enough. The 38kHz pulses have to be chopped on and off at certain rates. The required rates have to be matched to the range of on-off ratio that can be detected by the receiver, e.g. 16 pulses on, 24 pulses off.

The second requirement is that the basic carrier pulses have to be modulated with codes to control specific functions. There are standard codes and the user can also make up his own codes as long as it is decoded correctly at the receiver.

The descriptions above are about systems using standard IR receiver modules. You can make an IR remote control that does not follow those rules, but then you cannot use standard receiver modules and there has to be some form of coding to make them usable in practice.

To make a simple remote control that has to perform a single function like turning something on and off, you don't need further encoding besides the carrier requirements as described in the second para above. You don't need the HT12x or similar ICs. The carrier pulse itself is enough to do a simple switching function.

 

[Raza]

I want to do it using basics first then switch over to controller side..

Even though you do not want to use any Microcontroller but they make the life easy. Here is a link for HT12 dedicated IC for the purpose you is desirous. Do not use but atleast go through the article to get some knowledge.
I want to do it using basics first then switch over to controller side..

 

[beyondH]

@pjdd--first of all, thanks for the information..
can i say that a tsop1738 will respond to a standard tv remote i.e its output pin will show voltage variations when interfaced with t.v. remote???
also, ht12d/a/e/f..I have used these decoders/encoders with the rf modules.. can you please explain how can i use them with infrared one?

@Raza--no links given sir, you may have forgotten to paste it!!!!

 

[Raza]

Extremely sorry. Me an absent minded person
Anyways here it is:
How To Build The Fire-Stick Infrared Remote Control System Part 1

 

[Pjdd]

@pjdd--first of all, thanks for the information..
can i say that a tsop1738 will respond to a standard tv remote i.e its output pin will show voltage variations when interfaced with t.v. remote???

Yes.

also, ht12d/a/e/f..I have used these decoders/encoders with the rf modules.. can you please explain how can i use them with infrared one?

Download the datasheet for the HT12E/HT12A from **broken link removed**
You can use either the HT12E or the HT12A on the transmitter side, but the HT12A is designed specifically for use with IR remote controls. In the "Application circuits" section of the datasheet there's a schematic of the HT12A used as a 38kHz remote transmitter. Remember not to exceed the maximum supply voltage.

You can also download the datasheet fr the HT12D/F decoder for use at the receiver side.

 

[beyondH]

@pjdd--I made a very simple switch (led on/off using t.v. remote) and it is working absolutely fine...
in the datasheet it is given that these encoders/decoders works for "any RF or infrared transmission".....thnx. for the information...
so using this one can send 16 different signals..okk...
1.how can i send more than 16 signals i.e. a remote with 30 buttons??
2.can i transfer data between the detector and emitter using this concept??

 

[Pjdd]

The HT12A/E has 4 data lines and is most often used to send 4 different switching commands independently. The 4 lines could be used in binary combination to represent 16 different commands but the data rate will have to be quite slow because the effective clock speed connot be more than 1-2 kHz. Moreover, if the data (the binary combination) changes during transmission, it will take several clock cycles while the address and data lines are scanned and verified again.

To have more than 16 combinations, you can use the HT640 encoder and the HT648L decoder. This pair can use up to 8 data lines and could in principle be used for 256 different commands.

 

[beyondH]

yeah, thankss for your help...i will ask you if I get any problem while interfacing with these..