Water Level using 3 sensors

ESPHome
1

Hello… Looking for help on how to make this work,

i have a water tank, i used a Esp8266 with 3 XKC Y25 sensor

the 3 sensors are working has expected, Wet / Dry

i am looking to take advantage of the dual status and merge the 3 sensors to get more level

Exemple : Sensor 1 Wet = 100 %
Sensor 1 Dry = 80 %
Sensor 2 Wet= 60 %
Sensor 2 Dry = 40 %
Sensor 3 Wet = 20 %
Sensor 3 Dry = 0 %

captive_portal:
web_server:
port: 80

binary_sensor:

  • platform: gpio
    pin:
    number: GPIO16
    mode:
    input: true
    pulldown: true
    device_class: moisture
    name: “Liquid Sensor 16”

  • platform: gpio
    pin:
    number: GPIO02
    inverted: true
    mode: INPUT_PULLUP
    device_class: moisture
    name: “Liquid Sensor 02”

2

That is an incomplete logic table.

SW3 SW2 SW1 Vol
x x 1 100
x x 0 80
x 1 x 60
x 0 x 40
1 x x 20
0 x x 0

1 = wet
0 = dry
x = unknown

Please fill in the unknowns.

3

since there are only three sensors that are at increasing heights the table is easy (and does not support the requirements)

L3 L2 L1 Level
0 0 0 0%
0 0 1 20%
0 1 1 50%
1 1 1 80%
5
SW3 SW2 SW1 Vol VOLUME
x DRY DRY 100
x DRY DRY 80
DRY DRY DRY 60 100
WET DRY DRY 40 75
WET WET DRY 20 50
WET WET WET 0 25

So Only 4 level are possible ?

6
SW3 SW2 SW1 Vol VOLUME
x DRY DRY 100
x DRY DRY 80
DRY DRY DRY 60 100
WET DRY DRY 40 75
WET WET DRY 20 50
WET WET WET 0 25

So Only 4 level are possible ?

7

Before delving into the code, it can be helpful for me to start with the physical design.

Imagine a 100m tall tank with sensors placed at 25m, 50m, and 75m (let’s call the lowest sensor #1, and the highest #3).

The knowledge you have about the level of fluid in the tank based on the sensor readings is:

All sensors dry: less than 25m
Sensor 1 wet, others dry: above 25m, below 50m
Sensors 1 & 2 wet, sensor 3 dry: above 50m, below 75m
All sensors wet: above 75m

Depending on what you will do with this information will dictate your algorithm. For instance if you just want a description of the tank level, you could translate “all sensors dry” into “less than 25m” or “less than 25%”.

If you need to know when the tank is truly full and fully empty, you would need to add a sensor at the bottom and another at the top.

1 Like
8

tks for your reply… the goal is to know the level of water in the motorhome…This information will help me to plan the next refilled .Having a % is good.

9

It all depends on how accurately you need the level percentage and how much you are willing to spend to achieve this result.

I have a gray water tank in the basement with a sump pump in it. I never cared about the level, until the pump stopped working.

I put a ToF sensor in there, because it is cool, but I guess I didn’t look at it enough (and didn’t get an alert set up). I finally replaced the float switch and things are much better. I also put a level sensor about where the float turns on and below where the tank overflows that turns on a buzzer. That works well for me.

Figure out what you really need/want first.

10

I had a similar challenge with a cistern. I had two sensors which were “empty” and “full” I finally bit the bullet and bought a water level sensor (get 0-190Ω). If your tank is 325mm it cost USD$16.38. ESP8266, power for it, and a 480Ω resistor. Select one that is the right depth for your tank and you’ll have 1024 levels (not really, as the ADC is a little noisy, and the resistor has tolerance, so 200 levels? :wink: )

Let me know if you need more details.

OSD