I need some advice on infrared receiver frequency!!!

[expert]

Infrared!!!

I'm using a 38KHZ IR receiver to receive data from transmitter!! i suppose to generate a 38KHZ frequency to transmit data but i encounter a weird problem that i'm able to send data without generating a 38KHZ pwm by PIC( 16F877). Although the data which receiver receive is not correct but still manage to receive!!!

Is it necessary to generate 38KHZ pmw to send data?
Can anyone give me some advice???

 

[btbass]

Infrared!!!

The receiver has a band pass filter centered on 38KHz for noise imunity.
The transmitter saves power by modulating the ir code at 38KHz.

 

[Nahian]

Re: Infrared!!!

I'm using a 38KHZ IR receiver to receive data from transmitter!! i suppose to generate a 38KHZ frequency to transmit data but i encounter a weird problem that i'm able to send data without generating a 38KHZ pwm by PIC( 16F877). Although the data which receiver receive is not correct but still manage to receive!!!

Is it necessary to generate 38KHZ pmw to send data?
Can anyone give me some advice???

as far i know nt exactly necessary ....range bout 36~40kHZ is enuff.
is ur receiver TSOP?
make the frequency exactly 38kHZ using timer555;thn check ur receiver's response.U might hv the best respnse.

receiver still manage to receive may b due to sunlight.
normally for simple IR emii-receiver circuit need nt hv any specific frequency.

 

[expert]

Re: Infrared!!!

as far i know nt exactly necessary ....range bout 36~40kHZ is enuff.
is ur receiver TSOP?
make the frequency exactly 38kHZ using timer555;thn check ur receiver's response.U might hv the best respnse.

receiver still manage to receive may b due to sunlight.
normally for simple IR emii-receiver circuit need nt hv any specific frequency.

yes, my receiver model is TSOP 1138(38 KHZ)
anyway, thxs fot the advice!!!

Added after 2 minutes:

my infrared receiver can receive data but the data is wrong. can anyone help me!!!!The result is shown in the figure. the waveform on above is receiver input and the waveform at below is transmitter output.

 

[nandhu015]

Re: Infrared!!!

Is there any need for pwm?

Just on and off is enough i think

Regards
Nandhu

 

[ScratchBuild]

Re: Infrared!!!

Hi there,

You have to generate a specific frequency to generate the the data to be sent. In your case it would be 38Khz. You then have to implement a bandpassfilter at the other side the exclude as much of the unwanted interferences you can.

You then have to generate some sort of error checking to make sure you recieve the right data. You also have to design a protocol which will be robust enough to handle the situation. On the web there are many protocols for IR, just surf the web.

In any case why don't you use the TSOP1738 which already has all the functionality build in and the output is digital. You almost do not have to do anything to recieve good data on the other side.

Have a look at this site:

https://jap.hu/electronic/codec.html

Regards

Nic

 

[Nahian]

Re: Infrared!!!

I think u shld make proper circuit as it able to sense voltage(i donno bout ur citcuit) only when u want. i started working with the same receiver once...bt didnt actually use it atlast.Try other receiver..if u face probs. Tsop receives wrong data nt only in sun actually, bt also in daylight! so its hard.

 

[expert]

Re: Infrared!!!

Hi there,

You have to generate a specific frequency to generate the the data to be sent. In your case it would be 38Khz.

Nic

Today, i have generate a 38KHZ by PIC combine wif my data to transmit, it is able to transmit but the data receive are incorrect. is there any problem?
my coding is attach below for refer, thxs!!!

 

[expert]

Re: Infrared!!!

is there anyone got any idea y i can send data through Infrared but the data in the receiver side are incorrect????

 

[expert]

Re: Infrared!!!

Can i use UART to transmit and receive data by using infrared??

 

[kender]

Re: Infrared!!!

Can i use UART to transmit and receive data by using infrared??

Yes, you can.

 

[rohitjain]

I am making Ir transmitter and receiver both are working properly but only tsop is not sense sing the transmitter out put some please help me out!!!!!!!