Reading Wireless Air Transmitter using Arduino

[Timmyjane]

That's not really accurate. The original project did not die; it ended successfully. The goal of decoding the signal was achieved; see posts 131 and 163. Some folks wanted to go beyond the original goal and try and build some kind of receiver/transmitter and that progress has indeed been slow. Hey, it took a year and a half just to work out the decoding!

Working out the decoding was super impressive. I did read the whole thread and was blown away. It’s amazing what different people know. I was disappointed that there was no DIY transmitter built.

 

[tursiops]

It’s sound. I had no idea either. Pretty wild stuff.

The MH8A is RF at 38kHz, not sound. The Garmin transmitter uses sound.

Working out the decoding was super impressive. I did read the whole thread and was blown away. It’s amazing what different people know. I was disappointed that there was no DIY transmitter built.

@rg422 has documented the decoding project on GitHub at

https://github.com/rg422/PPS-MH8A-Transmitter.

What it needs is an Arduino buff with some time to jump on it.

 

[bananafeller]

This is on my radar to work on next year. I’ll probably start on this in February or March.

Just need to finish my ultrasonic Trimix analyser first ( link to repository still a work I progress and I’m self taught so the code might by terrible). I need to start a thread and write up on it at some point .

 

[Avataar120]

Hello,

Thanks to your hard work, I succeeded yesterday to read the signal from my Aqualung transmitter.
My setup is very simple : a 8ohm speaker placed on the transmitter and a scope.

The result is the following :

Each upward blue arrow is a "1", each downward arrow is a "0"

Preamble : 00
Sync1 : 1000
Sync2 : 0001
ID : 012860 (thx to the lookup table you gave)
Pressure : 1618 PSI / 111.5 bars
Battery : Good

Then I decided to write a very simple ESP32-S3 code to decode the signal.
It works pretty well :

I will now clean the code and if you are interested I will share it !

Thanks again for this 18 months of hard work to understand the signal coding !

 

[SquareJ]

Well done! I've watched this since the beginning and was thinking it might never be solved. I'd like to see the code when you get it to your liking.

Thanks for persisting.

 

[broncobowsher]

Okay, that is something that makes perfect sense but have never thought of before. Use a speaker coil an an antenna.

I've looked in on this project a few times. Always thought it was interesting, but never thought it would happen shy of someone getting the coding from the supplier. I am impressed.

 

[Avataar120]

Hi,

You can find the code and the instructions here :
github - Avataar120

If any remarks, don't hesitate !

 

[lidas123]

I am interested in what you are doing but for another reason, I need to make a command (remote control) that works underwater, so reading what you wrote what frequency do you recommend I use I need to do both TX and RX
38KHz is it ok for you and second question wifi or bluetooth
thanks