automatic pump controller

[Vraj]

hi

i am planning to make automatic water motor controller.
when the water level in my tank (which is located at top of my house) is less than some defined value, it will start motor by relay.
the motor is located at ground level and tank is 15 meter vertically far from motor.

i will use hc-sr04 ( ULTRASONIC SENSOR) to measure the water level in my tank.
i will mount uc( arduino mini) with hc-sr04 at top of the tank.
two wires will come for relay input from arduino mini.
wire length will ~20 meter.

now my problem is the ultrasonic sensor is sometimes reading distance incorrectly. the real distance was 20cm. i was watching reading for every 1 sec. of interval. i saw 0 value and nearer value (false value) for 3 times in 20 times of reading!

what to do?
please suggest me.
thanks in advance.

best regards
vraj

 

[KlausST]

Hi,

Use a reliable sensor.

Klaus

 

[Vraj]

This will both time and money consuming method.
I was expecting for change in code.
Kindly suggest. Thanks

 

[swapan]

i saw 0 value and nearer value (false value) for 3 times in 20 times of reading

I have made US Distance finder using HC-SR04 sensor and MCU 16F676 which shows almost accurate reading of distance between sensor and target. Though I have not tested it using water as target. But i think it should not show 0 or nearer value in any way. Post your code.