Leak sensor ?

xiholdtruex

New member
I was looking into trying to add some leak sensors under my stand to be able to alert me if any water is detected. I was looking at options and found these on amazon. Would I be able to just wire these to a sensor port and have it register if there is leak to alert me? or any recommendations for a sensor option Amazon.com
 
It looks like that sensor should work. You can wire it directly to the green plug on the sensor extension and set the jumper above it to P-U (pull up resistor). Let me know how it goes.
 
It looks like that sensor should work. You can wire it directly to the green plug on the sensor extension and set the jumper above it to P-U (pull up resistor). Let me know how it goes.
Thank you, I already have a few leak detection pucks under my tank I wonder if I would wire them up to work. took one apart today to see what they look like. They have a small round sensor up top and a 3 prong sensor on the bottom hooked to this board. They are powered by a single 9v battery. These remind me of the sensors at the bottom of dishwashers I see at work all the time. what do you think ?

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Thank you, I already have a few leak detection pucks under my tank I wonder if I would wire them up to work. took one apart today to see what they look like. They have a small round sensor up top and a 3 prong sensor on the bottom hooked to this board. They are powered by a single 9v battery. These remind me of the sensors at the bottom of dishwashers I see at work all the time. what do you think ?

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They would work if you can find a point that puts out voltage when water is detected. If you probe around with a volt meter you might find a source. Maybe check where the speaker connects, that might have voltage when it detects water and none when it doesn't or vice versa. If you do find that you could connect to a sensor port.
 
They would work if you can find a point that puts out voltage when water is detected. If you probe around with a volt meter you might find a source. Maybe check where the speaker connects, that might have voltage when it detects water and none when it doesn't or vice versa. If you do find that you could connect to a sensor port.
I can easily find that. When I find that I would pull from that wire and connect it to what side of the sensor port ? And would I need to pull another wire as well? I don't want to short out the pi lol

PXL_20250127_034833517.jpg
 
so when sensor is activated in water I am getting 9v to each speaker wire when tested to sground on board per picture. when sensor is dry it gets 0v
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Unfortunately 9v is to high, the max voltage can only be 5v. I'm guessing it's 9v due to the 9v battery, I wonder if that sensor would work with 5v. Instead of using the battery if you power it with 5v from the controller does it still work and put out 5v/0v when it senses water?

If not there's two options, you could add 2 resistors as a voltage divider to drop the 9v to 5v, you would need a 4.7k and 10k resistor. It would also be good to add a 3rd 10k resistor to limit the current to the GPIO.

Or you could use a 5.1v zener diode with a 10k resistor which would do the same. The 10k resistor will limit the current to the GPIO and the diode will only allow 5.1v max to the the sensor port. This option is best as it doesn't matter what voltage the battery is at. With the voltage divider the output will vary slightly depending on the battery voltage. For example if the voltage was 11v the voltage would be 7.5v with the voltage divider which is too high but if you used the diode it would still be 5.1v.

If you want to go this route I can make a diagram showing how to connect it.
 
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Unfortunately 9v is to high, the max voltage can only be 5v. I'm guessing it's 9v due to the 9v battery, I wonder if that sensor would work with 5v. Instead of using the battery if you power it with 5v from the controller does it still work and put out 5v/0v when it senses water?

If not there's two options, you could add 2 resistors as a voltage divider to drop the 9v to 5v, you would need a 4.7k and 10k resistor. It would also be good to add a 3rd 10k resistor to limit the current to the GPIO.

Or you could use a 5.1v zener diode with a 10k resistor which would do the same. The 10k resistor will limit the current to the GPIO and the diode will only allow 5.1v max to the the sensor port. This option is best as it doesn't matter what voltage the battery is at. With the voltage divider the output will vary slightly depending on the battery voltage. For example if the voltage was 11v the voltage would be 7.5v with the voltage divider which is too high but if you used the diode it would still be 5.1v.

If you want to go this route I can make a diagram showing how to connect it.

IMG-20250129-WA0027.jpg

I did some more probing and I get between 3-5vdc there when water is present. With no water it is 0. If that is the case do I run that 5v wire to the data to simulate a closing of a circuit correct? And leave the other two connections without any wires since the battery is providing the 5v to that connection correct?
 
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scratch that I just re tested all the terminals and they are testing at 9vdc to ground all the time and they drop to around 5 v when the alarm triggers. Just gave myself a nice 9vdc shock to my leg testing and figuring it out the hard way lmao
 
scratch that I just re tested all the terminals and they are testing at 9vdc to ground all the time and they drop to around 5 v when the alarm triggers. Just gave myself a nice 9vdc shock to my leg testing and figuring it out the hard way lmao
Ah that's unfortunate, did you try powering it with 5v to see if it still works?

The connectors are 3.81mm pitch, here's a link. There's a few slightly different variations but it looks like these are the same.

3 pin 3.81mm connectors
 
Ah that's unfortunate, did you try powering it with 5v to see if it still works?

The connectors are 3.81mm pitch, here's a link. There's a few slightly different variations but it looks like these are the same.

3 pin 3.81mm connectors

Thank you so much again Rob!! Will be ordering some more of those plugs. I am really enjoying the robotank again.

I have not tried the 5v but I will try later tonight, I would run a wire to the positive on the battery terminal from the robo and would I run the ground from the robo to the negative battery terminal? To supply it with 5v correct? I completely forgot to try it.
 
Thank you so much again Rob!! Will be ordering some more of those plugs. I am really enjoying the robotank again.

I have not tried the 5v but I will try later tonight, I would run a wire to the positive on the battery terminal from the robo and would I run the ground from the robo to the negative battery terminal? To supply it with 5v correct? I completely forgot to try it.
No problem, glad you're enjoying it.

Yeah replace the battery with +5v and ground from the controller, you can use any +5v source on the controller or extensions. The DC port grounds won't work though as those are switched. I think it might still work but maybe not enough power for the speaker or it'll be really quiet but maybe get lucky and all will be good.
 
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