water depth sensor

[halmus]

I'm working on another project that's not aquarium related, but has an obvious application in the aquarium hobby. The particular sensor network I'm putting together requires me to measure water depth through some sort of sensor network using an Arduino. I put this video together to let the guys I'm working with on this know where I'm at and a few solutions I have come up with to measure the depth. It's pretty poor quality, and I was rushed. I'm going to keep working on it. I see a definite use in future aquarium builds.

I'll try to update this as we get a working solution. Here's the video for right now:

water depth sensor - YouTube

 

[TJL]

Pretty COOL Jacob, definitely some aquarium applications here you can work with. I think that some of the or one of Tunze ATO setups utilize a sensor that measures sump low/level/sump highreadings that can override switches/pumps to not overfill. So something similar to this could be ran through an Arduino for added safety level. It would be really cool if you could build a Auto Level device for Herbie style drains that would control an electric gate valve or ???

Cheers, Todd

 

[halmus]

Thanks Todd. I actually just finished a DIY auto top off for the PSAS tank. I'll post up pics. The auto level device you're suggesting for the drain control is do-able. The main problem I see is that electronically actuated PVC valves are stupidly expensive and I believe they're either on or off. It would constantly be switching on/off. I'm sure there are valves out there that I'm missing which would work. Another way to approach the problem is to use water level to control the speed of a return pump. There are variable speed DC type pumps that would be integrated.

 

[TJL]

See.... got you thinking. I really like my Herbie drains for being dead-silent when properly adjusted but that means fiddling with them every few days or so. A DC pump or controller that could do micro adjustments would be a very nice addition to it.

Cheers, Todd

 

[halmus]

So, this is not the same project, but it's not entirely unrelated. A DIY auto top off. Why build my own? I don't like the typical top-off devices because they rely on a float switch that will constantly switch on and off the top-off pump. I wanted a top-off that would run a low voltage DC through the float switches and turn on a relay for a variable amount of time. Here's a few pictures of the "guts" of the device. A bunch of timing circuits, rectification circuitry, and a latch circuit that will be used to detect an alarm condition and notify the user until the circuit is reset.

The yellow LED flashes when an alarm condition is detected.
The green LED turns on when the relay is turned on and the auto top-off pump is running
The red LED turns on whenever the top-off is in the off condition

The potentiometer adjusts the amount of time the top-off pump is turned on. It's variable from .1 sec to about 12 sec.
The red push button resets the alarm
the black push button turns on the pump as long as the button is held down in case the user wants to manually control things.

The external wire attachment points are for the three separate float switches that can be attached.

The idea is that switches 1 and 2 will be used for low water sensing. Switch 3 will be a back up. If 1 and 2 fail, causing the pump to stay on and fill the sump up to the level of switch 3, that switch will open the circuit that allows the relay to close controlling the pump. That's just a back-up to make sure the sump can't overflow. Switch 4 simultaneously triggers the alarm circuit which sends an audible beep and runs the flashing yellow LED. Even if the water drops back down to acceptable levels, this alarm circuit will remain on to notify the user that something has gone wrong. The user can reset the alarm and check the floats to see if they need to be replaced.

Now, the remaining complaint I have is that typical floats we buy online degrade over time. The wires short out and the floats fail. So, I could easily use the idea from above (the water level sensors) to build mini PVC versions that will stand up to abuse and rarely fail.