Technical, Techniques, Hints, and Tips > Microprocessor control
Arduino Bilge Monitor
Umi_Ryuzuki:
We used to just do this... ok2
DJW:
Hi Umi
Same principle, but updated to the era of the Internet connected video doorbell... %)
Best regards
David.
derekwarner:
David......
1. Most bilge water sensing systems have a low to high level 'conditions' which are important elements of the system, in one important case, to eliminate the pump stop/start with a high frequency
2. Having a flooded suction for the pump on startup is also another consideration, which apart from positive flow, eliminates the shaft seal from running dry
3. Hawing little electrical knowledge, does the salinity of the water have a varying resistance within the circuit water probes?
I watch the twin minature peristaltic pump units of the 'Plasma separation machine' at the Blood Bank on each donation. these have the ability to run dry, and have positive suction. The load cells and circuitry of these machines is also intriguing :o
Derek
malcolmfrary:
Sensing water and just reporting it is one thing. Two sensors does a good job. If a pump is involved, it needs its own control to be operated from the transmitter.
Automatic pumping is another question again. For that to be effective it needs a ground common, a low level sensor and a high level sensor. The high level is the one that starts the pump, when there should be enough depth for the pump to prime. The low level keeps the pump running until the level drops to the point where the pump cant scavenge.
The drawback of the simple Darlington transistor is that the pump will tend to stutter - as soon as water is detected, the pump runs, drops the level a fraction, and stops. Depending on how fast the water is coming in, it repeats without dropping the unwanted water significantly.
Putting a CD4001 quad 2 input NOR gate chip, suitably wired, between the TIP120 and the probes sorts out the logic for about 50P pus postage. There was a discussion about this about 10 years ago. I did a drawing which was built and worked, but have since lost it. The version using a CD4066 worked, as well. Using an existing Arduino makes sense, its mostly just programming.
It is preferable that the probes either can't corrode or can be easily accessed for cleaning. Stainless is a good option. One bilge pump control maker way, way, back biased his probes with AC to try to eliminate the perceived problem. I suspect that the currents involved with CMOS inputs are low enough for this to be ignored given the operating life span of most models.
DJW:
Hi Chaps
Interesting points raised. I did look at the 'depth sensors as they're the first result when water detection is googled.
Seems they're just a row of sensor pairs, so one will trigger, then the next, and you can work out depth.
This would be quite straightforward to build and adapt to arduino, different levels triggering different input pins, then do something. Could be pump, indicate or whatever.
I do like those peristaltic pumps too, mainly as they don't need priming but also the pulsed delivery. If I get past this build and onto a larger version I'll be using one for the water to exhaust rather than the current conventional pump.
In this case my aim for the Bilge water detection is not to pump water out at all as I don't want any water in the hull, at all. And definitely not to keep running with water on board. So its enough for me to just detect water presence, and immediately warn via telemetry on the transmitter. Then I just make a beeline for the dock and investigate.
I've made up my own rudder and prop shafts and have used seals, but in the event of a failure of one of these seals, the results would be unthinkable. The prop shaft is of main concern, as I'm running exposed shafts the prop tubes are quite short, so there's not much volume for lube in the shafts. So a failure of the seals would go bad quite fast, I think.
With hindsight I could have used larger diameter tube for the prop tubes. They're not causing any drag as they're not exposed, so I could have made them more robust...
There's always next time...
Best regards
David.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version