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Help me with PWM decoder of a RF remote control for PIC

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Junior Member level 3
May 15, 2001
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Hi ,

Does anybody have any code written in C to decode the PWM output of a RF remote control (from a car alarm) . Doesn't have to be code hopping just read the code so that I can display it .

Thanks in advance


:lol: :lol: :lol:

pwm decoder ic

Car alarm's transmitter units usualy uses coder IC.
This IC's output signals not PWM.

All ICs uses different codes.

remote control+pic+pwm

Hi bunalmis, :lol:

The transmitters that I have use a PIC and definatley you PWM as an out put .

They transmit a 25bit signal (3 * 8bit + a "0" at the start for preamble)

A "0" is 300uS high then 600uS low , a "1" is 600uS high then 300uS low.

I was going to sample the data every 300uS to calculate the data but I thought I would ask first . why reinvent the wheel.

The decoder chip in the reciever is also a PIC


Schmitt :lol: :lol:

pwm pic decode

Ok you can this coding. But this coding name is it pwm ?

You use fix on and off time.

pwm decode pic

Do you have physical access to the receiving

Nick C.

pwm forpic

I've interested too.

pic pwm decoding

Yes , i have access to the reciever.

The transmitters have two buttons . the first arms the car alarm , the second activates a panic alarm when the alarm is disabled . The alarm has a LED "ARMED" output so I wired a SSR to that and I use it to remote turn on some lights in my garden . I bought several reciever hybrids and I am going to attach them to a PIC so that I can use both buttons to control 2 items rather than just the one.


Schmitt :lol: :lol: :lol:

pic pwm decoder

Hi Schmitt,
You can use a sample code how to read remote control's data from here:
**broken link removed**
There are samples in assembler and C.
This programmes implement reading of Microchip's code hoping encoders based on KEELOQ technology and they are too complex, but you can get just the part responsible for receiving the code. The format of the data is a little diferent from your case , but it is easy to make some corrections in the program to satisfy your needs.

decoder pwm

Thanks Stefk,

I will have a look and see.

Schmitt :lol: :lol: :lol:

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