snooping a 2.4ghz remote control

stator

Anyone know of an app for Android or a Desktop program that will record and display the signal broadcast from a remote control that works on 2.4ghz? (for a camera).
Searching for apps all I can find is stuff tailored for WiFi, which is not needed as it's just a dumb remote control that uses the same frequency as WiFi.

were

Good luck with this one!

The closest I have been able to find is (1)Spectrum Analyser, but it cost too much even second hand, but suppose it could be rented. http://www.stewart-of-reading.co.uk/ (2) is a wild card, and is Software Defined Radio. Many devices go to 1.9GHz, but you do get 3GHz ones (ebay around £180).

The problem with these, is that even though they can listen at that frequency, can they decode what the devices is sending. Will the device send fm or am, and is it broadcasting tones or pulses or frequency shift.

Heedtheadvice

Were, is quite right.

There are systems out there that will do all sorts of things with radio signals.... receive, demod, decode, provide baseband outputs that can then be 'recorded'.
Many are professional systems but you can get some basic amateur/hobby equipment. Professional ones are most likely we'll outside any budget you have unless this is a business query!

However to get any help you need to provide much more info about what your aim is - I assume you do not want to record the high frequency signal but maybe it's signal level or the data being transmitted- the type of signal, camera and anything you can post about the signal.

were

I would tackle it differently.

Because I am old, my memory and eyes are shot, I would take a macro photo of the circuit on the fob, and if you are lucky they have not sanded town the chip surface (or encapsulated it), so it still has its part number, then I would google the chip part number, and if you are lucky you will find a circuit very similar to yours that show you what is going on, and if you are really lucky you will get an explanation too

Geoff1963

a remote control that works on 2.4ghz? (for a camera).

Maplin do some 2.4 GHz kit : receivers and video senders. They might be able to receive it, but not tell you what it means. If you have the device, call in one of their shops and see what they can tell you about it.

stator

Essentially I want to emulate the signals sent by this remote:

https://www.banggood.com/2_4G-Remote-Control-for-EKEN-H8R-H9R-Sport-Action-Camera-p-1088639.html

So that I can trigger the camera to take photos from a program running on a raspberry pi or laptop or mobile phone

were

I am not a Raspberry Pi person, but I would tend to go towards opening the device up and then connect a relay to the button, power the relay from the pi i/o pins.

You may be able to force the pi into action from your phone - realistically I have no idea beyond this, as I do not even have a Pi

looks like 4 screw on the back


from your link, under questions, someone asked "Compatibility"
"Hi, it only can compatible with EKEN camera." = looks like closed source. You could contact the camera people, perhaps there is an app. They should also know the codes sent/used/format

paddyrg

were wrote: »

I am not a Raspberry Pi person, but I would tend to go towards opening the device up and then connect a relay to the button, power the relay from the pi i/o pins.

from your link, under questions, someone asked "Compatibility"
"Hi, it only can compatible with EKEN camera." = looks like closed source.

Since it looks closed source it's likely a specific programming of a microcontroller which is likely be be a simple COB with blob of epoxy straight on the board. Using the Pi or whatever to trigger the remote seems like a good approach compared with reverse engineering a signal that is far too fast for most logic analysers.

Heedtheadvice

^^^^^^ I am with were and paddy on this.

Even ignoring speed, emulating the coding will not be straightforward and then you need to interface to a radio transmitter that has the same modulation characteristics.

Given the cheap cost of the item then interfacing to the keys' circuit to just emulate key presses would seem an easier and cheap way forward.

Remains a risk that it will not work but you will soon find that out without wasting lots of time and money.

Geoff1963

I would tend to go towards opening the device up and then connect a relay to the button, power the relay from the pi i/o pins

Exactly.
If you have the remote, and it's working ( or you can get one ), run wires off its keyboard to perhaps some reed relays, so that each relay "presses" a particular button. Then you can control it however you want.

A good example where the answer isn't obvious from the question.