Hey @cmerritt82 and @SpikeyGG!
I recently bought two pressure sensors with the goal of monitoring before / after PSI drops through water filtration. They’re both plumbed in and now I get to wire them into my utility-room esp32. Have either of you made any updates to your pressure-sensor esphome configs?
@carpenike, I had created this thread to understand better how to get two readings at the same time from a single trigger and I’ve implemented it and been using it for a long time. It works very well and that way I am comparing pressure sensor values that are much closer to being measured at the same time. It’s a bit confusing but if you look at how the update_interval, on_raw_value, and on_value keys look you can figure out how it’s working:
sensor:
- platform: ads1115
multiplexer: 'A0_GND'
gain: 6.144
id: incoming_water_pressure_raw
update_interval: never
accuracy_decimals: 1
internal: True
filters:
- calibrate_polynomial:
degree: 4
datapoints:
- 0.455 -> 0.0
- 0.722 -> 10.0
- 0.824 -> 15.0
- 0.948 -> 20.0
- 1.061 -> 25.0
- 1.178 -> 30.0
- 1.280 -> 35.0
- 1.398 -> 40.0
- 1.501 -> 45.0
- 1.622 -> 50.0
- 1.738 -> 55.0
- 1.859 -> 60.0
- 1.977 -> 65.0
- 2.097 -> 70.0
- 2.209 -> 75.0
- platform: ads1115
multiplexer: 'A1_GND'
gain: 6.144
id: outgoing_water_pressure_raw
update_interval: 1s
accuracy_decimals: 1
internal: True
on_value:
then:
- component.update: incoming_water_pressure_raw
- component.update: delta_water_pressure
filters:
- calibrate_polynomial:
degree: 4
datapoints:
- 0.539 -> 0.0
- 0.775 -> 10.0
- 0.854 -> 15.0
- 0.963 -> 20.0
- 1.051 -> 25.0
- 1.148 -> 30.0
- 1.232 -> 35.0
- 1.348 -> 40.0
- 1.432 -> 45.0
- 1.530 -> 50.0
- 1.637 -> 55.0
- 1.743 -> 60.0
- 1.854 -> 65.0
- 1.971 -> 70.0
- 2.078 -> 75.0
- platform: template
name: "Delta Water Pressure"
id: delta_water_pressure
update_interval: never
unit_of_measurement: "psi"
icon: "mdi:kettle-alert"
accuracy_decimals: 1
lambda: |-
return (id(incoming_water_pressure_raw).state - id(outgoing_water_pressure_raw).state);
on_raw_value:
if:
condition:
sensor.in_range:
id: delta_water_pressure
above: 1.0
then:
- lambda: |-
id(delta_water_pressure).publish_state(x);
on_value:
then:
- component.update: incoming_water_pressure
- component.update: outgoing_water_pressure
filters:
- throttle: 10s
- or:
- heartbeat: 300s
- delta: 0.5
- platform: template
name: "Incoming Water Pressure"
id: incoming_water_pressure
update_interval: never
unit_of_measurement: "psi"
icon: "mdi:gauge"
accuracy_decimals: 1
lambda: |-
return id(incoming_water_pressure_raw).state;
- platform: template
name: "Outgoing Water Pressure"
id: outgoing_water_pressure
update_interval: never
unit_of_measurement: "psi"
icon: "mdi:gauge-low"
accuracy_decimals: 1
lambda: |-
return id(outgoing_water_pressure_raw).state;
- platform: hx711
dout_pin: D0
clk_pin: D1
gain: 128
name: "Salt Bin Weight"
update_interval: 10s
unit_of_measurement: lbs
icon: "mdi:shaker"
accuracy_decimals: 1
filters:
- median:
window_size: 61
send_every: 60
send_first_at: 6
- lambda: return x * -0.0000911 + 23.3;
Every second the internal outgoing “raw” sensor is measured and that triggers an update of the internal incoming “raw” and delta sensor values. The delta sensor in turn updates the published outgoing and internal values that make their way to home assistant.
I have been toying with a couple of ideas that I haven’t acted on but may in the future:
If I do eventually do one or both of these things, it’ll likely be mostly for the data collection aspects. 
Very nice!
I’ve got a whole home meter that I installed awhile back. Works really nicely with a pulse sensor: Amazon.com: DAE MJ-100 1" NSF61 Lead Free Potable Water Meter, Pulse Output + Couplings: Garden & Outdoor
Also had purchased a third transducer to put after my water softener to get a good indication on how the overall filtration impact water throughout the flow. My water comes from a well so I have a pump on the well tank that keeps things between 40-60 PSI.
If you’ve got this already, that’s awesome! My plan was to use ESPHome filters to fall back to a heartbeat when the flow rate is effectively zero (like a measurement every 10 minutes) and amp up the sample rate when it’s non-zero (like every 250ms or something). That way you get good resolution to pressure drops when there’s in-house usage and you get a low resolution read at all other times (static pressure state). Thinking of the softener… it’d be really cool if we could somehow measure the softness of the water because I can tell mine fluctuates weekly-ish. I wonder if there’s a sensor for that. 
Thank you for your project and for the photos. I’m using wemos D1 mini, ads1115 and pressure transductor up to 170psi. Are you connecting also some resistors in your schema? It’s not very clear by the photo for me. Thank you
@malesci, you should read my response or some of the thread. The details you seek are well documented at this point.
Hello, forgive me if I insist. I have read the whole thread. But from the photos I couldn’t figure out if you also used resistors. I understand that ads1115 has 5v, gnd and pins 0 to 4 for the analog signal. But from your photo there is a tangle of wires and resistors and I did not understand the connection diagram.
Here I’m referring for the connection between ads1115 and wemos d1 mini.
In your message (always thank fro your help), it is described the connection between sensor and wemos, it’s right?
Sorry, it should look just like this:
Thanks a lot. Once the ads1115 arrives, I will try it!
hello, I have been trying to make this work for me, but i have a different need, I also would need to know the water volume in a tank in which the sensor is at the bottom of the tank.
I have two questions:
#1: what would the formula be to convert from psi to litres or %
#2 Is my formula for calculating the pressure is ok, I am not sure as I don’t fully understand the math involved.
Using a nodeMCU esp8266 on the analog input directly without resistor
I am using this formula which i got through your post:
- platform: adc
pin: A0
name: "water pressure"
update_interval: 2s
unit_of_measurement: "psi"
icon: "mdi:gauge"
accuracy_decimals: 1
filters:
- multiply: 5.0
- lambda: return x*43.75-21.875;
I get a reading of 22.1 psi from a half full tank , it seems a lot for a 45x55x35 tank (+/-70L)
here are the specs of the sensor: Output Signal Power Supply 0-10PSI 0.5–4.5V/0–5V
I would really like to get to understand this. and especially to have it work for me.
any help is welcomed!
/fabien
Fabien, your message is confusing. You know that we can’t convert from PSI (which is a pressure) to Liters (which is a volume), right? There is no equation for that. If you want to convert the PSI (imperial) to Bar (metric) that is possible and googling should give you the equation for that conversion. If you want volume of water in the brine tank I still think that weight (using a scale) may be your best approach.
hi thanks for your answer.
I am sure it is possible i’ve actually seen it done in various ways its done in the water towers as well there are multiple formulas which I found on internet but the problem is that i dont understand them, so I cant use them.
basically i guess I need math help regarding this sensor to find the level in % or litres it doesn’t matter. Doesn’t need to be extremely precise either.
We know water that is 0 degree celsius will weigh 1kg per litre. im guessing there would be a way to find out the amount in a tank using all these infos, I just dont know how.
Pressure is defined as the force per unit area. Besides force and area, it is also proportional to the altitude, density, and acceleration due to gravity. Mathematically,
this:
this:
this:
P α ρgh
P = ρgh
where P is the pressure (1 atm = 101325 Pascals, where 1 Pascal = 1Newton/square meter)
ρ is the density of water (1000kg/cubic meter)
h is the altitude or height
g is the acceleration due to gravity (9.8 meters/second square)
Manipulating the equation:
h = P/ρg
h = [(101325)/(1000*9.8)]
h = 10.33928571 meters
h = approx. 10. 339 m
I just suck at math too much to decipher how to do it … if someone could help me I would be eternally gratefull.
again my current mini tank is:
55’x45’x35’ so roughly 70liters
sensor reads 16.2 psi and has 1/4 of the capacity of water
I’m assuming you have two components to your water pressure reading and that it hasn’t been calibrated to return 0 psi in the open air. If so, you need to subtract the air pressure, like this if your air pressure is 14.7 psi:
(16.7-14.7)psi x (101325/14.7)Pa/psi/(1000)kg/m^3/(9.8) m/s^2
= 1.4 m
I’m not sure how you are getting your values as you are mixing units like wildfire. Is it 55 feet wide?
If you are measuring a saline tank the density is also much higher.
I am not, it’s just plain water for a “almost” fully automated garden on my 3rd floor terrasse here in Montreal city.
any help would be really appreciated since the reason for this automation is my working in cinema and sometimes have long stretch of work and little home time to care for my precious garden…
thank you
I misread your message, 16.2 psi is 1.1 m water height. This is 1.5 psi above ambient. This matches the conversion table you provided. I would suspect that the remaining difference is something to do with the psi reading too high.
If the reading is consistent, but still too high, you can calibrate it at different heights to get you the correct reading.
hi, thanks again for taking the time.
is “ambient” a constant or its a changing number?
the container is 50cm tall with a 45cm water level maximum. So this is not right.
It’s located on a terrasse on my 3rd floor city appartment, I am guessing that that height also has to be taken into consideration?
Thanks
sorry, i’m from canada and here for some strange reason we still use some imperial measures (construction work, some foods etc…) while most is in metric, i dont know why we do this, it is stupid… and because of that i keep mixing both when talking to non-canadian people about construction and food…
hahaha