Hello guys, I am building an aquarium monitoring system, that for now only measures the temp, and the water level of the aquarium. The problem that I am having is that the water sensor is getting too hot when it is put in the water for measuring the water level. I've connected the negative to ground, positive to 5v (If I connect to 3 volts it doesn't work), and the signal pin to A0. Please help. It gets really hot and I don't know what to do with it. Also, when I power the TMP 36GZ externelly with a breadboard power supply it reads too high of a temp.
- Always show us a good schematic of your proposed circuit.
Show us good images of your ‘actual’ wiring.
Give links to components.
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This is not a water level sensor, so you are going to have to share some information about the sensor you are having trouble with if you want assistance.
that's about the other problem about the external power.
Regardless, no one here can help you unless they know what hardware you are using, and how you have wired it.
If the sensor is getting hot, then it could be fake or connected wrong..
Post a picture of the setup.
The TMP36 is an analogue sensor, so temp readout highly depends on Vref and the supply of the Arduino.You must switch to one of the internal reference voltages of the Arduino to make this sensor less dependent on (USB) supply voltage.
If you don't have analogReference(INTERNAL in setup(), then expect instability.
It could be much easier to use a digital sensor, like the DS18B20, than to make this analogue sensor work reliably.
Leo..
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The sensor is probably wired incorrectly, damaged or both.
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Aside from the fact that sensor is not waterproof (how was it physically put in the water? And how were the cables?) if it gets hot I agree with @Wawa.
But why/how using a temperature sensor to get water level? It doesn't make any sense to me... There are a lot of possible ways to read water levels, starting from a plain standard ultrasonic sensor pointing downwards to the water surface, to laser, floating sensors, and more.
I should have thought of that I was using the water level sensor to display how much water there was and when to automatically replace it.
Check out this (very old) project of mine for an ultrasonic level indicator that I built for an espresso machine, although I don't know in what context you are trying to do this you might find some useful ideas:
I have used the ds18b20-waterproof-temperature-sensor and a jsn-sr04t waterproof ultrasonic sensor in a river monitoring system for a couple of years
also used TOF sensors for water level measurements in tanks
TMP36 temperature sensors work well if connected correctly.
Read the data sheet and application notes.
I've never had one overheat, so might suspect a wiring problem.
As for level sensing, you have many choices.
Optical methods work well, either inside or outside the tank. I track the level of a siphon in a boiler with an infrared trasmitter and combined photodiode/amplifier.
I think Honeywell did one you could strap on the outside of a transparent vessel.
Float switches, ultrasonic as mentioned. An old washing machine pneumatic switch repurposed.
The method widely used in industry is conductivity.
Two wires, for prototyping, about a centimetre apart, used with a transistor or a CMOS IC is simple to implement and interface with a microcontroller.
Strictly speaking, you use AC current, but at the very small currents with a CMOS device, it doesn't matter. Stainless steel probes, graphite. Polarisation isn't an issue at microamps.
You might need more than one level sensor for safety.