Reading Wireless Air Transmitter using Arduino

[MadUKDiver]

Just retested, It works, I guess I didn't put the tx in the right place when testing the first time.

Cool. I've finished the simulator app I was working on which you can download here.

It's written in VBA .NET5.0 64-Bit but should run standalone. No need to install (despite the setup.exe file) just unzip into a folder (can be on a USB stick) and run the Oceanic TX Simulator.exe file. It's a clean app, nothing saved to registry etc.

If you select the save to disk function it will create a wav file in the same folder as the main exe file. If you select continuous play it will transmit every 5 or so seconds depending upon the model of TX you choose. You can run two copies together with different settings to simulate multiple transmitters. Of course none of this will work unless you have a sound card like yours. I've tried playing the wav on various laptops, MP3 players etc and none are capable of producing high enough frequencies so your sound card is pretty special.

Also for download are a few more wav files, one to test the maximum possible psi value, the other to try battery code 0011. I wonder what they will show on your Teric?

Let me know how you get on?

 

[tursiops]

I'm not getting any reception on my Teric. What is a good way to couple the output of my speakers to enable the reception?

 

[rg422]

I'm not getting any reception on my Teric. What is a good way to couple the output of my speakers to enable the reception?

What I did was connect a pair of disposable headphones to my audio output, then cranked up the volume 100% then placed the earbud on the top left side of the teric, right between the top left button and the left side of the strap. The antenna seems to hear the signal in this position. I will test the program tonight.

Also for download are a few more wav files, one to test the maximum possible psi value, the other to try battery code 0011. I wonder what they will show on your Teric?

Will do soon. How much work would it be to implement a receive and decode function into the software? It would use soundcard IN so you could in theory use a coil attached to the mic port or use a virtual audio cable from a SDR software like SDRplay which I've been using to record the samples.

 

[tursiops]

Perfect. My ID works, the pressure shows as set, and the three battery levels show.
I had to plug my computer sound output into an amplified external speaker, and then just set the Teric near the speaker.
Good job, guys!

 

[rg422]

Also for download are a few more wav files, one to test the maximum possible psi value, the other to try battery code 0011. I wonder what they will show on your Teric?

For any pressure above 5000 my Teric just displays 5000.

Sweet program you made! Can you setup a github repository for this code? I can set it up for you if you are unfamiliar with the site. It would be valuable to track changes.

 

[TheScubaPanda]

Cool. I've finished the simulator app I was working on which you can download here.

View attachment 708714​

It's written in VBA .NET5.0 64-Bit but should run standalone. No need to install (despite the setup.exe file) just unzip into a folder (can be on a USB stick) and run the Oceanic TX Simulator.exe file. It's a clean app, nothing saved to registry etc.

If you select the save to disk function it will create a wav file in the same folder as the main exe file. If you select continuous play it will transmit every 5 or so seconds depending upon the model of TX you choose. You can run two copies together with different settings to simulate multiple transmitters. Of course none of this will work unless you have a sound card like yours. I've tried playing the wav on various laptops, MP3 players etc and none are capable of producing high enough frequencies so your sound card is pretty special.

Also for download are a few more wav files, one to test the maximum possible psi value, the other to try battery code 0011. I wonder what they will show on your Teric?

Let me know how you get on?

Could you create a github repository ? I'd love to be able to play with it

 

[rg422]

Could you create a github repository ? I'd love to be able to play with it

Yes, here you go: GitHub - rg422/PPS-MH8A-Transmitter: Decoding the signal used by SCUBA wireless air integration systems
I made that repository to track developments of the various bits of code related to this, I've got a rough roadmap in the readme and in the wiki I explained how to record and analyze the signal.

 

[TheScubaPanda]

Yes, here you go: GitHub - rg422/PPS-MH8A-Transmitter: Decoding the signal used by SCUBA wireless air integration systems
I made that repository to track developments of the various bits of code related to this, I've got a rough roadmap in the readme and in the wiki I explained how to record and analyze the signal.

You're a legend

A few questions, this thread is hard to follow:

1. Any difference in the data transmitted between transmitter V1 and the Swift (V2) ?
   
   
2. Do they transmit battery voltage ? or battery level (good/low/critical) ? Or % ?
   
   
3. They really transmit pressure in PSI ??? It's a Canadian company why they don't do it in BARs ?
   

It's a shame we can't tinker the firmware of the computer, could you imagine if we could transmit the O2 cell PPO2 on a rebreather using wireless. Not talking if that would be safe or not safe, just would be fun to do

 

[Gone for diving]

It's a shame we can't tinker the firmware of the computer, could you imagine if we could transmit the O2 cell PPO2 on a rebreather using wireless. Not talking if that would be safe or not safe, just would be fun to do

How hard would it be to make a stand alone p02 meter wirelessly... I can make a wired one no problem.... but wireless is a bit beyond me....

 

[rg422]

You're a legend

A few questions, this thread is hard to follow:

1. Any difference in the data transmitted between transmitter V1 and the Swift (V2) ?
   
   
2. Do they transmit battery voltage ? or battery level (good/low/critical) ? Or % ?
   
   
3. They really transmit pressure in PSI ??? It's a Canadian company why they don't do it in BARs ?

It's a shame we can't tinker the firmware of the computer, could you imagine if we could transmit the O2 cell PPO2 on a rebreather using wireless. Not talking if that would be safe or not safe, just would be fun to do

1. Presumably no, the swift just checks to see that the channel is clear. Since it is backwards compatible.
2. No, just good, low, or critical
3. As far as I can tell yes. Pelagic Pressure Systems designed the protocol and original transmitters, they're based in San Francisco, California.

We can wirelessly transmit nearly any info from back mounted hardware to a watch/ computer, the hard parts is hardware/software integration. These transmitters work great for pressure but only pressure. It would be possible to copy the concept of these transmitters, VLF radio signal, and pair that with a dive computer with custom firmware that listened for and decoded/displayed your new data.

In order to not be reinventing the wheel we would need a dive computer company to bless us with a way of flashing firmware to our computers, something that is unlikely as open source endeavors are not very profitable.

Do your computers have that I2C or whatever port on them for reading the P02 data? Because it would be totally possible to make a module that attached to the sensor and computer data ports and sends that signal wirelessly. It would be a significant amount of work and likely result in more bulk being added than a streamlined cable.

Disclaimer, I know nothing about rebreathers other than what some YouTube videos taught me.