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# water level indicator using PIC16F877A

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#### vishnudevan

##### Newbie level 1
please can anyone help me how to do water level indicator using PIC16F877A.Its urgent please send me the post at earliest .

u can use ultra sonic sensor to measure the water level

Rakibhossen

### Rakibhossen

Points: 2
I think thermistor is good for water level detector circuit. (thermistor resistance will vary with temp.)

Rakibhossen

### Rakibhossen

Points: 2
anandpv2009 said:
I think thermistor is good for water level detector circuit. (thermistor resistance will vary with temp.)

how u can use thermistor in a water tank?

Its resistance will vary when contact with water(due to reduce in tem.) by using A/D you can read the value (using scanning method).

You can do this even without using MCs.

Arrange thermistor on a stich as shown below.

|
|
|_ Thermistor 1
|
|
|_ T2
|
|
|_ T3
|_ Empty

T1 means the tank is full
T2 Half
T3 Low water level

If all reading are low then the tank will be in empty.....

Its resistance will vary when contact with water(due to reduce in tem.) by using A/D you can read the value (using scanning method).

as far as i know "A thermistor is a type of resistor whose resistance varies with temperature."

what gonna happen when the temperature changes
morning
afternoon
night
temperatures r different ???

in winters well water is usually warm
in summer well water is cold

hameeds01 said:
Its resistance will vary when contact with water(due to reduce in tem.) by using A/D you can read the value (using scanning method).

as far as i know "A thermistor is a type of resistor whose resistance varies with temperature."

what gonna happen when the temperature changes
morning
afternoon
night
temperatures r different ???

in winters well water is usually warm
in summer well water is cold

You are right. You can provide a POT at A/D input of MC to correct the variations (It is not essential). But for project purpose/indoor purpose it is possible.
I am sure it will work because I have some experience with this project (in my project i were used thermistors).

The above link explains hot water level indicator. It is also possible with normal room temp. water. As i mentioned above you can use a port to change the reference resistance value.

I think the above explanation is enough...

Here is another link for water level detector
https://www.electronics-circuits.com/cirdir/analog/mixed/del20024.html

the link you given is only useful for hot water, for normal water it is not useful , and in day time the water may get a little warm that effect the reading.

the best method is to check the water pressure and the simple method is using test leads

Hi,
How about this? I used this method once with a PIC16F84A(yes, when I was starting to learn programming) to sense the level of water in a container(small one) just after it rained.

The lines marked "-" are made of conducting material. You can use tin plates or something similar and there can be as many as you want.
Each of these will connect to an NPN transistor. So that whenever water reaches a specific level, that many transistors will be turned on and each of these will pull the input pins of the microcontroller low and then you can use the microcontroller to sense the level.
The battery positive is stuck to the bottom of the conductor. Beware! The container can not be made of conducting material.
Hope that it helped and that you understood.
Tahmid.

direct electric contact to the water is not good for a pro. quality system.

"pure water is an insulator"

True, but I doubt he's going to use "pure water".

Try putting two parallel insulated wires into the tank and measure the capacitance between them. The value will jump dramatically as water reaches them and will then change proportionately to the water depth.

Brian.

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