Shearwater DiveCan configuration changes

[LFMarm]

Hi all,

Situation. I have a Diverite OptimaCM (mod. 2022) that I am controlling with a NERD 2 and monitoring with a Shearwater HUD – everything on Shearwater DiveCan as far as I understand. I am exploring options to replace my HUD with another computer but have not fully figured out what are all the versions of computers (controller DiveCan, monitor 4 PIN, monitor Fisher, ...) and what combinations of these work together so please be patient if I ask below weird questions .

DiveCan context. For those not used to DiveRite CCRs, the controlling cable is tagged green and the monitor cable is tagged blue. They physically look the same. My CCR doesn't have the optional auxiliary port shown in the scheme below.

Questions

• If I want to replace the HUD on the monitor cable (blue) with a Petrel, what kind of Petrel can I use? I would guess the 4-pin type. Is it ok if it was born as Petrel controller instead? If yes, does it matter for which rebreather was supposed to be a controller?
• In case I switch to a different controller, can I use my NERD 2 controller as a monitor by moving it from the controller cable (green) to the monitor cable (blue)?
• If I switch to a Petrel, I would like to be able to use the Petrel also as a backup for OC diving (I am currently using a Perdix 2 for this). I understand that in the Fisher version of the Petrel, you can easily remove the cable and use a metal cap (picture below) that makes the Petrel similar to the stand alone version and easy to use in OC. Can you do the same with the DiveCan version of the Petrel (picture also below)?

 

[makar0n]

Questions

• If I want to replace the HUD on the monitor cable (blue) with a Petrel, what kind of Petrel can I use? I would guess the 4-pin type. Is it ok if it was born as Petrel controller instead? If yes, does it matter for which rebreather was supposed to be a controller?
• In case I switch to a different controller, can I use my NERD 2 controller as a monitor by moving it from the controller cable (green) to the monitor cable (blue)?
• If I switch to a Petrel, I would like to be able to use the Petrel also as a backup for OC diving (I am currently using a Perdix 2 for this). I understand that in the Fisher version of the Petrel, you can easily remove the cable and use a metal cap (picture below) that makes the Petrel similar to the stand alone version and easy to use in OC. Can you do the same with the DiveCan version of the Petrel (picture also below)?

​

So others will have a better idea, especially if you can attract @tbone1004 here, but do not think you can mix DiveCAN and 4 pin - one talks currents/voltages the other 1's and 0's. That would be like plugging a speaker cable from your amp into ethernet card and expecting that your amp can now talk to your computer. Most likely you will fry things.
That said, this could in theory work if you would get some kind of a DAC-ADC converter....

If you want to replace HUD, you just need another DiveCAN device i.e. same plug as the HUD has now.

No, I do not think you can switch controllers. Firstly you would need a device compatible with DiveCAN - sadly none exist, other than Shearwater at this point. Secondly, as far as I was told by Shearwater, these controllers still have rebreather specific firmware of sorts i.e. you supposedly cannot take Nerd from Revo and plug it into Choppy and expect it to work, at least that is what I was told by Shearwater...

Yeah I would love if one could change the controlling system,, this would be really awesome if one would not be stuck with just a single computer manufacturer.

 

[LFMarm]

I am happy with Shearwater but want to figure out how I can change my current config from NERD 2 (controller) + HUD (monitor) to any of the options below:

1. Petrel 3 (controller) + NERD 2 (monitor) — using the same NERD 2 I currently have as controller
2. NERD 2 (controller) + Petrel 3 (Monitor) — using a Petrel 3 “controller” so that if NERD fails, I have a backup with me when on far locations (would swap the Petrel as controller and keep going)
3. NERD 2 (controller) + Petrel 3 (Monitor) — using a Petrel 3 DiveCan monitor

I am pretty sure the third option would work but it’s my least favorite of the three.

 

[makar0n]

Hmm I think there is such thing as too many computers
My preference is to have Nerdy as a controller, as apart from the ease of use and having that pO2 right in my face, that way air freshener is self contained - i can take it off underwater all as one piece, and don't have any cables running down my arm. Also easier when gearing up. My current setup is in fact Nerd + HUD+ Perdix as a backup (normal, not monitor). Said Perdix also performs OC duties should Choppy be pausing the dive. (sadly no way to copy tissue loading between...would be great if Shearwater implemented that so one could update Nerdy on your OC dives done between ones on a Choppy on the day/trip.)

Now best would be if one could disattach DiveCAN cable - that way you could get a Petrel, and use it as a backup/OC, but if needs be, plug the cable and use it as a controller. But alas, nope, you get to buy a 3rd computer as you cannot disconnect DiveCAN cable.... You could still use it as backup/OC probably but gotta both protect the plug and stuff the cable somewhere if not connected.

Also not 100% sure but choice 2 and 3 on your list are about the same - I think if you plug the controller into the monitor port, it will just behave as monitor. I am a bit confused between the controller vs non-controller-but-still-DiveCAN versions...

 

[LFMarm]

Also not 100% sure but choice 2 and 3 on your list are about the same - I think if you plug the controller into the monitor port, it will just behave as monitor. In fact I am a bit confused between the controller vs non-controller-but-still-DiveCAN versions.

That is my doubt as well. Not sure if there are 2 versions of the Petrel DiveCAN — one as controller (option 2) and one as monitor (option 3). If there is actually only one DiveCAN version that can be used either as controller or monitor, then the 2 options are the same.

 

[makar0n]

That is my doubt as well. Not sure if there are 2 versions of the Petrel DiveCAN — one as controller (option 2) and one as monitor (option 3). If there is actually only one DiveCAN version that can be used either as controller or monitor, then the 2 options are the same.

Yeah, this is where I am confused - I thought DiveCAN version is the controller version, but when I at some point asked Shearwater if I could get a Nerd DiveCAN from Revo, they said nope, those controllers are rebreather specific with some special firmware or settings or something...so dunno whether that is the case or they just want to "motivate" you to buy yet another computer xD

 

[LFMarm]

I am pretty sure you can run a computer as a monitor — only question is if there are 2 versions of the computer, one that runs as a controller (I understand why it would be CCR specific) and one as a monitor or if you can just take any controller and once you plug it in the monitor cable, it acts as a monitor

 

[tbone1004]

I am happy with Shearwater but want to figure out how I can change my current config from NERD 2 (controller) + HUD (monitor) to any of the options below:

1. Petrel 3 (controller) + NERD 2 (monitor) — using the same NERD 2 I currently have as controller
2. NERD 2 (controller) + Petrel 3 (Monitor) — using a Petrel 3 “controller” so that if NERD fails, I have a backup with me when on far locations (would swap the Petrel as controller and keep going)
3. NERD 2 (controller) + Petrel 3 (Monitor) — using a Petrel 3 DiveCan monitor

I am pretty sure the third option would work but it’s my least favorite of the three.

I do not believe that the controllers will behave properly on the monitor bus. You can try it on yours and see if the NERD behaves plugged into the HUD cable but I would be surprised if it did without errors since it is looking to talk to the SOLO and it's talking to the OBOE. Worth a shot. If it behaves then buy a Petrel 3 controller from Dive Rite and you get option 1/2 but I think you'll have to do option 3.

 

[LFMarm]

I do not believe that the controllers will behave properly on the monitor bus. You can try it on yours and see if the NERD behaves plugged into the HUD cable but I would be surprised if it did without errors since it is looking to talk to the SOLO and it's talking to the OBOE. Worth a shot. If it behaves then buy a Petrel 3 controller from Dive Rite and you get option 1/2 but I think you'll have to do option 3.

Thank you — testing it out soon with the NERD 2 controller mounted on the monitor cable

 

[LFMarm]

I did some testing and would like to report back for the benefit of others looking into these options.

When you plug a Shearwater controller on the OBOE circuit, it shows a small error message in yellow in the same spot where you see SP=0.19 that says "No solenoid" "No O2 sensor". Despite that, everything but the controlling capabilities (changing set points) works, i.e., it monitors and displays the reading from the O2 sensors and all computer functionalities work. Not sure why it says "No O2 sensor" given it can read the sensors.

This means that you can dive with 2 controllers – one plugged to SOLO (this is the one that will fly the unit) and one plugged into OBOE (this will just read the sensors and do the deco calculations). I think this is an interesting option in case you dive in very remote locations and you want to have a controller backup. If you do that, you can as well use it to read the sensors instead of the HUD. The additional benefit is that, in case of main controller failure, you can plug the monitor into the controller and have all the tissue profiles from previous dives.

As a side note, if you disconnect the controller from the SOLO circuit, the electronic will chase whatever setpoint you last programmed with the controller (so you can keep diving in electronic mode even with a main controller failure). Not sure if in this case you would be able to switch the cables underwater in order to start using the backup controller or if you better do it on the surface.