Arduino Forum

Topics => Device Hacking => Topic started by: srsmitherman on Dec 25, 2017, 10:24 pm

Title: Mimic a 315MHZ Fan remote - looking for advice.
Post by: srsmitherman on Dec 25, 2017, 10:24 pm
I have a 315MHZ remote that I want to capture/decode.
In order to simplify this product i got a 315 MHz reciever and transmitter board.

I have tried using analogRead and digitalRead while outputing to the Serial Monitor and Serial Plotter.

I am definitely getting a response you can see from the video below.

The problem I am having is that when no button is pressed on the remote it seems to be oscillating from high to low.

Also the chip on the remote has no marking on it so i cannot look up a data sheet for this chip.

I cannot seem to determine the speed at which the bits are being outputed.

Looking at the raw 1 and 0 stream the number outputed from the digitalRead loop are different lengths. But they are exactly repetitive for the same button pressed on the remote.

Maybe this is outputing PWM signal and not a binary output?

To make the binary output easier to read I have started a new line every time a 1 is outputed. Take a look.

Any suggestions would be greatly appreciated.
Title: Re: Mimic a 315MHZ Fan remote - looking for advice.
Post by: Paul_KD7HB on Dec 26, 2017, 06:39 pm
Remove the battery from the remote and see what you get. The you can eliminate what the remote is sending from your data. Bet you are seeing something other than signal from the remote.

Paul
Title: Re: Mimic a 315MHZ Fan remote - looking for advice.
Post by: jremington on Dec 27, 2017, 04:03 am
To decode the RF signals from unknown devices, start with a receiver, a laptop and Audacity, following this great tutorial (https://rayshobby.net/reverse-engineer-wireless-temperature-humidity-rain-sensors-part-1/).
Title: Re: Mimic a 315MHZ Fan remote - looking for advice.
Post by: srsmitherman on Dec 27, 2017, 01:28 pm
Project complete. Thanks for the help. I found a library called RCSwitch that will decode these type of devices. Then you just output the code on your transmitter. I like the link you posted jremington. I have never used the sound card to sample signals. I am going to try this being I still have not spent the money on an oscilloscope. If any has questions I am happy to provide direction.
Title: Re: Mimic a 315MHZ Fan remote - looking for advice.
Post by: jremington on Dec 27, 2017, 04:20 pm
Quote
I found a library called RCSwitch that will decode these type of devices.
Did you try it, and does it actually work? If so, that is quite surprising!
Title: Re: Mimic a 315MHZ Fan remote - looking for advice.
Post by: srsmitherman on Dec 28, 2017, 01:08 am
Works great. I am using the Blynk app to control it from a esp32.