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Discussion Starter #1
My O2 unit is supposed to ship in next two weeks. To get it wet while waiting for the monitors I need a PO2 display. I've got 7 pcs of Lascar panel meters left over from an other project.

DPM 1AS-BL | Panel Instruments

It's the same model as used in Classic KISS. I'm going to build a simple PO2 meters from these. Just now I'm thinking about the design. 3 in one housing, totally separate housings, one common power supply, separate power supplies, machine a housing, use PC tube etc....

I've got 20mm PC tube from an other project. The displays fit inside with small modifications. One design option and the easiest to build is to place all 3 panels in the same tube and place an enclosed battery in the sensor pod. Maybe I build this first and make and totally independent model later. The independent model would have 3 enclosed batteries in the pod. 3 wires leave the pod and lead to 3 tubed with panel meters. These tubes can be stacked side by side.

CAD pictures will follow as soon as I get them finished.

Is there any "safe" batteries that won't off gas? These could be placed in the sensor pod without gas tight enclosures. If you flood the unit, just replace the batteries on surface. The O2 sensors are also not flood proof but batteries may off gas.
 

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Duvet Diver
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If you put the battery in the sensor pod, you are running power and signal down the same bundle of wires, It can be designed for, but it's not considered good practice.
Another way is to put the battery in the display housing, if you use a decent water/gas blocked cable like the one [email protected] sell by the meter between the displays and the sensor pod, the battery can off gas as much as it wants without affecting the loop.
How much work are you going to put into the displays? could it be easier to use this at 469 euros inc taxes?
HTH
Simon A
 

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I personally wouldn't want any batteries in the loop... I think any battery could off gas at one time (unless potted/encapsuled).
As much as I love DIY, nowadays, there are quite good and proven PPO2 displays around (like HW, rEvodreams,SW etc) at reasonable prices.
If ask around, there should be some 2nd hand ones available.
Anyway, just my thoughts, good luck with the project...

Ivan
 

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Discussion Starter #4
After a little bit of research I won't place any batteries in the loop. But I probably place them in the pod to save space in the handset.

Cells are isolated with an OP-amp circuit. This way I can later add hud, second handset etc. and keep them all isolated so wire cut and shorts don't screw all displays.

I have access to a manual and a CNC-mill so I can machine a handset for the DPM displays. Or I can make the tube design with all DPM displays in the same tube. The tube design would be 113mm long (including the cable gland) and 20mm in diameter. I won't make an own housing for all 3 DPM displays. This is bad for redundancy but I have plans to add DIY HUD and maybe a second handset.
 

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Hi Plasma,

Many on this board and others have been this path before and is very interesting and amusing, the homebuilders spirit, love it.
As far for redundancy, a HUD is great, but don't forget in mCCR online-deco is far better/safer than fixed PPO2 or tables with bottom timer.
I have a Mark Munroe single cell display (Lexan tube, reed contact, pot meter cal etc) laying around somewhere.
if I can do you a favor with that, you can have it FOC (postage is on you), pm me

Ivan
 

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Discussion Starter #6
I have a Mark Munroe single cell display (Lexan tube, reed contact, pot meter cal etc) laying around somewhere.
if I can do you a favor with that, you can have it FOC (postage is on you), pm me
Thanks for the offer but that design is too big.

The idea of a KISS style display on the O2 Apoc is to be able to dive it manual CCR while waiting for the monitors. I don't want any complicated or expensive. Using DPM displays is easy.
I can later use the parts in other DIY project. A deco computer would be nice. I sold my VR3 years ago. Maybe I'll buy a second hand unit since they are very cheap. But for the start a bottom timer or a nitrox computer is enough.

Building a HUD is also quite easy. The second handset is more complicated since I have planned to use a 1,5" OLED display in it, electronic compass and maybe even deco algorithm.
These may take more time than the arrival of the Apoc monitors. So I may not use these in the Apoc.

I'm a electronics designer so electronic and coding microcontrollers is easy for me. I can also use mills and lathes.
 

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Discussion Starter #8
I got two 1.5" OLED displays for free. I'll use one of these in the advanced handset. A CR123A battery could be a good match for the size. I'll have to do some math to see the how long the handset works with the battery. Luckily the display is alot like one other Densitron display I have worked with. So should be no problem to get it running.

 
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