Water level expansion more details please!

dazza1304 · Post by **dazza1304** » Sun Sep 30, 2012 3:55 am

Hi, have been looking at the above, but cannot see any details on sensitivity etc?

Does anyone have any details as to what sort of fluctuations in water level this is able to resolve and with what sort of accuracy?

rimai · Post by **rimai** » Sun Sep 30, 2012 8:02 am

The full scale of range is technically 4096, which is the resolution of the sensor that is used.
Although at 0 PSI, means atmospheric pressure and the pipe is not immersed into water, the sensor already outputs around 900. So, there is some negative pressure that can be measured too. Not much and the sensor is not really made for that. So, let's just round it to 3000 resolution.
The pipe that comes with the module is 9in long. So, if you take 9in and divide by 3000 resolution, you get 0.003" resolution, which is about .08mm
So, the precision over the length of 9in, which is the pipe that comes with the unit, is less than a tenth of a millimeter.
The sensor is actually capable of measuring up to 400mm.
But, internally, we scale it way down to measure % of the pipe and not length, so your resolution gets down to 1%.

dazza1304 · Post by **dazza1304** » Sun Sep 30, 2012 8:41 am

Hi Roberto - thanks for a comprehensive answer - as always!!

TanksNStuff · Post by **TanksNStuff** » Fri Oct 05, 2012 9:11 pm

Roberto, do you have any pics of this in action? I'd like to see how it's setup and how it looks in the sump.

My Tunze Osmo controller just crapped out on me and I'm looking for an alternative for my ATO.

rimai · Post by **rimai** » Fri Oct 05, 2012 9:36 pm

http://i761.photobucket.com/albums/xx25 ... 212956.jpg
http://i761.photobucket.com/albums/xx25 ... 213058.jpg
This is how I have mine.
Basically all you need is to have the pipe standing straight. I have mine placed inside the bubble trap walls with the pipe just standing there with nothing else holding it.

TanksNStuff · Post by **TanksNStuff** » Sat Oct 06, 2012 6:51 pm

Thanks for the pics Roberto. That gives me a better understanding of how it would be installed.

My Tunze pump wasn't my issue, it was the controller. Since it was shot, I decided to cut/splice the power wire of the Osmo directly to the pump. The pump works whenever it's plugged in, so that was good news.

Then I swapped out the Osmo's sensor/float switch for the pair of floats that came with the RA package and now I'm just working on a new set of code to upload. I would have had it up and running a while ago, but I've been toying around with other pieces of my code (changing slope to parabola, cleaning up commented out old code, commenting, etc.) so I haven't gotten it all worked out yet. I'm pretty confident it will work though.

If I'm not happy with the way the floats keep my sump level, maybe I'll look into that water level expansion. I'm a big fan of those pressure sensors anyway.

lnevo · Post by **lnevo** » Sat Oct 06, 2012 7:35 pm

Can the PVC pipe be changed out for different length? Just calibrate and go?

TanksNStuff · Post by **TanksNStuff** » Sat Oct 06, 2012 7:51 pm

Roberto said it measures % of the pipe and not length, so I'm guessing the pvp pipe could be changed for a shorter or longer one, with calibration of course.

rimai · Post by **rimai** » Sat Oct 06, 2012 8:08 pm

Correct. Standard 1/2" pvc pipe.
Up to about 15in or cut shorter too.

lnevo · Post by **lnevo** » Sun Nov 04, 2012 3:02 pm

Trying to calibrate my water level sensor and having a great deal of trouble... When I measure 0%, the number is at 220 or so. When I add water to the container I'm using to test in, the number starts dropping and then hits 0 and rolls back to 255 (I think) and keeps looping around. When I calibrate after 100%, the controller showed Water Level: 80 and then starts fluctuating. What am I missing, did something need to be initialized first?

rimai · Post by **rimai** » Sun Nov 04, 2012 5:31 pm

It should be around 900-1000 for 0%.

lnevo · Post by **lnevo** » Sun Nov 04, 2012 5:36 pm

Well its definitely not...and like i said, the value wraps around when i start filling...not sure if this is a library version issue, memory initialization or a bad sensor. Is it normal for the number to e lower the more full it is?

Also after i calibrate, the value bounces around in like 5-15% jumps...

rimai · Post by **rimai** » Sun Nov 04, 2012 5:40 pm

what numbers do you get with this code?
For 0% and 100%?

Code: Select all

#include <Salinity.h>
#include <ReefAngel_Features.h>
#include <Globals.h>
#include <RA_Wifi.h>
#include <Wire.h>
#include <OneWire.h>
#include <Time.h>
#include <DS1307RTC.h>
#include <InternalEEPROM.h>
#include <RA_NokiaLCD.h>
#include <RA_ATO.h>
#include <RA_Joystick.h>
#include <LED.h>
#include <RA_TempSensor.h>
#include <Relay.h>
#include <RA_PWM.h>
#include <Timer.h>
#include <Memory.h>
#include <InternalEEPROM.h>
#include <RA_Colors.h>
#include <RA_CustomColors.h>
#include <RF.h>
#include <IO.h>
#include <ORP.h>
#include <AI.h>
#include <WaterLevel.h>
#include <ReefAngel.h>

void setup()
{
  ReefAngel.Init();  
  ReefAngel.Relay.AllOn();
}

void loop()
{
  ReefAngel.LCD.DrawText(0,255,10,50,ReefAngel.WaterLevel.Read());
  ReefAngel.ShowInterface();
}

lnevo · Post by **lnevo** » Sun Nov 04, 2012 6:04 pm

It stays around 224 when in no water. When I fill up a container with the sensor in a pitcher, it rolls around till different numbers but usually settles in the 100's bouncing around, but mostly in that range. I've seen it flash 3-400 but never stays put. Am I testing it incorrectly? Does it need to create a vaccum. I cemented the cap to the tube to make sure it was sealed...

rimai · Post by **rimai** » Sun Nov 04, 2012 6:17 pm

224 is too low.
Does it show the same numbers without the tubing??

lnevo · Post by **lnevo** » Sun Nov 04, 2012 6:26 pm

218-219 without the hose.

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