I'm beginning to research ways to develop a display (bar graph seems most effective) for water tank level on a 12V vehicle system. The commercially available units for this task are very expensive and I believe it can be done much cheaper. (FRC Tank Vision, Hale Intelli-Tank)
Project details:
12V power supply through vehicle.
Rectangular poly water tank. Approximately 36 inches in height.
Need to display inside the cab with some type of indication of tank level. I think a series of LEDs or a bar graph would be ideal.
I am 100% new to the Arduino world and don't really know where to start.
My initial thought was to use a 0-5V pressure transducer to transmit to some type of controller that would output on the display, but of course that is easier said and done.
I'd try to research how the commercial sensors work. A fuel tank usually has a float connected to a potentiometer. A potentiometer is easy with the Arduino.
I don't know if a pressure sensor will be sensitive enough... Maybe...
When playing around in a pool as a kid I found out that with a couple of feet of water there's enough pressure that you can't breath through a hose! (At the time, I didn't really understand what was going on.) I'm sure that's measurable but I don't know if such a sensor is economical.
An ultrasonic distance sensor might also work,
If you end up with a 12V sensor that puts-out a 0-12V analog voltage, you can knock-down the voltage with a voltage divider (2 resistors).
There are lots of displays that work with the Arduino. A "string" of LEDs to make a bar-graph would be the easiest.
Yep, I asked that, because if you didn't need level measurement, but only indicator for certain level, you could have used level switch instead of sensor.
Anyway, for clean water, almost any sensor can work. Pressure, distance, capacitive, floating hall sensor etc.
That is pretty cool. The 32" version is only $50 which is probably in the range of other technologies and the interface is a resistive divider so simple or no conditioning required.
Most tanks in automobiles are mounted crosswise in the frame, so most motions produce small fuel movements. Also there are baffles in the tanks to limit sloshing around. The 20 gallon tank in my truck is long and narrow and is mounted so the long way is in line with truck motion. It can easily show 1/4 full and a minute later show 1/2 full depending if on the flat or on a hill.
