Smart Home Automation Forum

Hi, I want to know if I can use KC868-COLB Logical Controller to measure water level using the 2wire 4-20ma water sensor. Picture below.

KC868-COL/COLB/COLB-Mini support use analog sensor that 0-5V output, if you already have 4-20mA sensor. you can use a 250 Ohm resistance connect with signal input port and GND to convert.

To convert a mA analog input signal to voltage you need to attach a inline resistor. The size of your resistor will determine the output range of your voltage. 

Resistor Calculations are as follows:

Using ohms law V = R(I)  (Voltage = Resistance * Current)


If we were to scale a 4-20mA to 1-5V

For the 0 Value: .004 Amps * 250 ohms = 1 Volt

For the Max Value: .20 Amps * 250 ohms = 5 Volts

i Also have the same sensor and want to connect to my kc-868 server analogue input

the sensor has an output value of 0-10v
 
please guide me how to use it

KC868-Server analog port only support 0-5v or 4-20mA signal analog sensor.
if you are using 0-10v sensor, you can try to find a convert module on market, let 0-10v convert to 0-5v signal.

the output from the senor is coming from 0-4v but it is not coming on the home assistant

This is my yaml configuration

- sensor:
- name: "Water Level (%)"
state_topic: 'server/42dd7407672e64273d439978/adc1'
unit_of_measurement: "%"
value_template: "{{ ((value | float) * 2) * 10 }}" # Converts 0-10V into 0-100%


- name: "Analog Digital Input 3"
state_topic: "server/7ffd88f939adfbe3340ee686/adc1"
unit_of_measurement: "V"

i am getting no values on home assistant.

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my tank is smaller and i am getting values in between 0-5v maximum

i think the mqtt topic only use for digital input and digital output ports, not by ADC.
you can use state_topic: 'server/42dd7407672e64273d439978/state' to check whether have value feedback.

i changed it still there are no values coming to it

take a photo of your mqtt state feedback message.

here is the data received at analogue input 2

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here is the change in data too

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from 88 to 84