ir modulator

[bogdanfirst]

i have a TSOP1736 IR demodulator, 36Khz.
i need to make a circuit for modulating and sending inormation. i have some IR emitter leds.
what i need is to create a serial comunication from one PIC to another.
any simple solution?
i will eventually replace the IR link with a radio one.
thanks in advance

 

[Nigel Goodwin]

i have a TSOP1736 IR demodulator, 36Khz.
i need to make a circuit for modulating and sending inormation. i have some IR emitter leds.
what i need is to create a serial comunication from one PIC to another.
any simple solution?
i will eventually replace the IR link with a radio one.
thanks in advance

Have a look at my PIC tutorials, I have one on IR remote control, it's very easily changed to send 8 bit data.

 

[bogdanfirst]

well, what i want is to have a transmitter with an input for digital, and a receiver with the output for digital. and i need to build a transmitter....wich will modulate for 36KHz....
so i'll need like a 36Khz oscilator wich will be turned on or off depending on what input i have?

 

[Nigel Goodwin]

well, what i want is to have a transmitter with an input for digital, and a receiver with the output for digital. and i need to build a transmitter....wich will modulate for 36KHz....
so i'll need like a 36Khz oscilator wich will be turned on or off depending on what input i have?

You can just generate it directly in software, it's very easy to do, so your transmitter uses one PIC, and your receiver another one.

 

[bogdanfirst]

but i already have the pic programmed. it's an OTP....and it is not mine.
anyway..thanks for your help. i think that i will just wait for the radio modules to arrive and use them directly. thanks.

 

[Nigel Goodwin]

but i already have the pic programmed. it's an OTP....and it is not mine.
anyway..thanks for your help. i think that i will just wait for the radio modules to arrive and use them directly. thanks.

Right, you'd not mentioned that before!.

 

[PoniesArePretty]

DEMODULATOR HELP!!

Can anyone PLEAASSEEEEE help me with a demodulator circuit. I am designing an Infrared receiver with a carrier frequency of 36Khz. I have first amplified the signal then I added a band-pass filter. Now I need to add in the demodulation stage.
If anyone of you could help me with the VHDL code for the demodulation stage, that would be great I am planning to add the circuit as well as the VHDL code (for demodulation).

The general idea behind my receiver can be found at this URL:
**broken link removed** [The receiver]

Thank you
ro

 

[Nigel Goodwin]

Re: DEMODULATOR HELP!!

Can anyone PLEAASSEEEEE help me with a demodulator circuit. I am designing an Infrared receiver with a carrier frequency of 36Khz. I have first amplified the signal then I added a band-pass filter. Now I need to add in the demodulation stage.
If anyone of you could help me with the VHDL code for the demodulation stage, that would be great I am planning to add the circuit as well as the VHDL code (for demodulation).

Why reinvent the wheel?, IR receiver IC's are freely available and extremely effective - a single IC with three pins that outputs a demodulated signal on one of the pins.

It's extremely doubtful you could match the performance of these devices, in particular instability is a massive problem with the huge gains required for a descrete solution.

As for VHDL code, you are probably looking at a PLL detector circuit - can you do that in VHDL?.

 

[PoniesArePretty]

DEMODULATOR

Thanx for replying back... It is actually a project that we are expected to do (otherwise I wouldnt have tried to make it myself.. using a chip is way easier..) neways so the project is to make an IR communication system.. my part is to make the receiver transmitter.. I realised (after a lotta browsing..) that there are about 6 stages to making the receiver.. i have finished the first two.. being the receiving stage.. then amplifying and then thew band-pass filter stage.. now i need a demodulator.. and then i am gunna add in da comparator stage.. .. if u need more background to this project .. u can go to ..
**broken link removed**


thanx

 

[Nigel Goodwin]

Re: DEMODULATOR

Thanx for replying back... It is actually a project that we are expected to do (otherwise I wouldnt have tried to make it myself.. using a chip is way easier..) neways so the project is to make an IR communication system.. my part is to make the receiver transmitter.. I realised (after a lotta browsing..) that there are about 6 stages to making the receiver.. i have finished the first two.. being the receiving stage.. then amplifying and then thew band-pass filter stage.. now i need a demodulator.. and then i am gunna add in da comparator stage.. .. if u need more background to this project .. u can go to ..
**broken link removed**

Right, so it's not intended as a practical project, just a low tech college example!.

An AM demodulator just needs a diode and a capacitor (a half wave rectifier), but a better way for this application is to use a PLL, something like an NE567 tone detector PLL, the output pin toggles as it receives it's tuned frequency. This makes it very simple to implement a sensitive 36KHz detector, and provides a direct logic output.