Do you have an example of pinout and setup? I’m trying to replicate this!
Appreciate you!
I’m assuming you are using the multiplexer because you are using and esp8266 and not an esp32?
Do you use a separate sensor for your temperature? I purchased the same sensor and I cant get it to pick up on the temperature setting at all
Hello hello,
I’ve applied the configuration you posted @ontdamian
But when looking in Home Assistant it appears that sometimes got a spike
Is it a known problem ?
To clarify:
I’m using cd74hc4067 multiplexer to read analog values from pH meter and TDS meter with one esp. Esp has only one analog input A0, that’s why I had to use cd74hc4067 multiplexer which allows to read up to 16 analog sources. As mentioned above for correct TDS reading you also need temperature sensor. I’m using simplest DS18B20. TDS meter can’t be powered whole the time because it distorts pH readings.
Here is my pinout:
- Multiplexer SIG to A0 on esp
- Multiplexer S0 to D5 on esp
- Multiplexer S1 to D6 on esp
- Multiplexer S2 to D7 on esp
- Multiplexer S3 to D8 on esp
- pH meter signal to C0 on multiplexer (if your signal is 5V make sure to use voltage divider to 3.3V)
- TDS meter signal to C1 on multiplexer
- TDS VCC to D0 on esp
- DS18B20 to D2 on esp
Here it as it works:
- Signal from multiplexer (A0) is updated every 5 sec.
- Every 10 sec multiplexer reads pH meter signal (C0)
- Every half hour at 5th sec TDS is powered on by D0 pin of esp for 200 ms and multiplexer reads TDS raw signal (C1)
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Thanks for this helpful reply 
I’ve already :
- One DS18B20 plugged https://www.amazon.fr/dp/B01MZG48OE?psc=1&ref=ppx_yo2ov_dt_b_product_details
- One TDS sensor Amazon.fr
Could you please tell me which pH meter you have ?
Can I use the 3.3v of the ESP to connect the pH meter ? If not do you have any link to buy voltage divider ?
I will buy both of Multiplexer, pH meter and voltage divider
Thanks
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Thanks for the detailed instruction! I built it but I’m struggling that my PH sensor measure constant 1V. I recabled, changed the USB cable and the power supply, tried with 5V with 3.3V converter, with 3.3V, still the same. 1V. Anyway the TDS/EC working fine and get the correct value. I created a config without the multiplexer and in this case the PH sensor measuring the correct values so I’m totally lost.
Hey,
How do you stop biofilm from ruining the results?
Cheers
I want to do a TDS sensor for my organic hydroponic system and I am wondering how you are liking your setup??? Would you do anything differently??
I am Wondering if a more expensive ($200) TDS sensor from Atlas is worth it or if a cheaper one is just fine
so i followed your calculations;
since I don’t have a temperature sensor connected to my wemos, i’ve swapped any temperature bits with “25”. While testing the sensor by dumping it in a bottle of lemonade-syrup, i’ve reached a ppm of 15. I then put the sensor in my hydro bucket where it started around 3.39 without adding any nutrients. The readings have been swinging a little bit, rising ever so slightly. Then today I put in fresh water and i’m reading 2.44 ppm. I’m guessing I’m going wrong somewhere in the formula calculation.
My code is below, mind giving it a look and telling me where i’m being stupid?
sensor:
- platform: adc
pin: A0
name: "tds raw voltage"
id: tds_raw_v
update_interval: 5s
unit_of_measurement: "V"
icon: "mdi:water-percent"
internal: true
# Temperature Compensated Voltage
- platform: template
name: "TDS TCV"
id: tds_tcv
unit_of_measurement: 'v'
accuracy_decimals: 3
lambda: 'return ((id(tds_raw_v).state) / (1 + (0.02 * (25) - 25.0)));'
update_interval: 5s
internal: true
# Temperature Compensated TDS
- platform: template
name: "TDS"
id: hydro_tds
icon: "hass:water-opacity"
unit_of_measurement: 'PPM'
accuracy_decimals: 2
update_interval: 5s
lambda: return ((133.42*(id(tds_tcv).state)*(id(tds_tcv).state)*(id(tds_tcv).state) - 255.86*(id(tds_tcv).state)*(id(tds_tcv).state) + 857.39*(id(tds_tcv).state))*0.5) * -1;
- platform: template
name: "EC Reading"
id: ec
unit_of_measurement: 'EC'
accuracy_decimals: 2
update_interval: 5s
lambda: return (((id(hydro_tds).state) * 2) / 1000);
I know i should up the update_interval because it has no reason to be at 5 seconds, but this was mostly for testing purposes. i’ve already put them back to 120seconds to give the esp a lil break now and again.
Sorry for my late response, I’m not visiting this forum so often…
Finally I had to get rid of TDS meter, because even if was powered by esp every half hour, pH meter readings were constantly distorted. I removed multiplexer and TDS meter and now pH readings looks much constant. There are still big differences between max and min readings, but after using median it looks good and credibly:
I’m using simplest pH probe and board/module from AliExpress:
It’s connected like here:
but without lcd and using 3.3V diverter based on 2k2 and 3k3 ohm resistors to be more stable.
After setting this up, pH V readings on A0 need to be calibrated with voltmeter and ph buffers:
filters:
- multiply: 3.1
# Measured voltage / 3.1 -> Actual pH (buffer solution)
- calibrate_linear:
- 2.244 -> 9.18
- 2.487 -> 6.86
- 2.783 -> 4.00I think your formula is incorrect. After substituting 25 for the temperature value it should look like:
((id(tds_raw_v).state) / (1 + (0.02 * (25 - 25.0))))but I’m not sure if you can simple use 25…
I have a CQRobot CQRADS1115 TDS sensor. Trying to get it integrated into Home Assistant. Will this code work for that? I also have dallas temp sensors already configured and working for temp comp.
### TDS 01
# Raw TDS Reading
- platform: ads1115
multiplexer: 'A0_GND'
gain: 6.144
name: "TDS 01 Raw"
ads1115_id: ads1
id: tds01_raw
update_interval: 10s
unit_of_measurement: "v"
accuracy_decimals: 3
internal: true
# Temperature Compensated Voltage
- platform: template
name: "TDS 01 TCV"
id: temp01_comp_v
unit_of_measurement: 'v'
accuracy_decimals: 3
lambda: 'return ((id(tds01_raw).state) / (1 + (0.02 * ((id(probe01).state) - 25.0))));'
update_interval: 10s
internal: true
# Temperature Compensated TDS
- platform: template
name: "55G TDS 01"
id: tds01_55g
icon: "hass:water-opacity"
unit_of_measurement: 'PPM'
accuracy_decimals: 0
lambda: return (133.42*(id(temp01_comp_v).state)*(id(temp01_comp_v).state)*(id(temp01_comp_v).state) - 255.86*(id(temp01_comp_v).state)*(id(temp01_comp_v).state) + 857.39*(id(temp01_comp_v).state))*0.5;
# Temperature In °C
- platform: dallas
address: 0x6f01205fd42aa428
name: "Probe 01"
id: probe01
unit_of_measurement: "°C"
internal: true
# Temperature In °F
- platform: template
name: "55G TEMP 01"
id: temp01_55g
lambda: |-
return id(probe01).state * (9.0/5.0) + 32.0;
unit_of_measurement: "°F"
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Yes that should do it
I made a youtube tutorial (in Spanish but with english subs) about how use TDS sensor and integrate with HA:
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Would it still be connected like this? (On A0 instead of A1, and Im using a nodemcu)…Can’t get it to read the sensor.
Will this work with the ADS1115 as well?
Yes, I’m using “board: nodemcu-32s”, and dual sensors on both “A0_GND” & “A1_GND”
Almost certainly yes, although you may have to adjust the gain, you can check the RAW voltage with a multimeter
I know this is an older thread, however I am trying to do something similar here to monitor the TDS in an RODI filter. With that I will not be using a temperature probe and understand the significance of requiring temperature compensation.
I am new to ESPHome so am unsure how to essentially set the temperature compensation to 25.0 as a pre-defined value rather than one calculated by a probe.
I also have 3 TDS sensors and noticed above someone mentioned they have 4, so would love for someone to shed some light.
This is what I have so far but it wont compile because I am obviously using the wrong syntax/code
dallas:
- pin: GPIO23
sensor:
- platform: dallas
address: 0xb7000006c34eb728
name: "Aquarium Temperature"
id: aquarium_temperature
icon: "mdi:water-percent"
unit_of_measurement: "°C"
device_class: "temperature"
state_class: "measurement"
state: 25
filters:
- offset: -2.0
- platform: adc
pin: GPIO0
name: "Tap TDS Raw Voltage"
id: tapTDS_raw
update_interval: 120s
unit_of_measurement: "V"
icon: "mdi:water-percent"
internal: true
# Temperature Compensated Voltage
- platform: template
name: "tapTDS TCV"
id: taptds_tcv
unit_of_measurement: 'v'
accuracy_decimals: 3
lambda: 'return ((id(tapTDS_raw).state) / (1 + (0.02 * ((id(aquarium_temperature).state) - 25.0))));'
update_interval: 120s
internal: true
# Temperature Compensated TDS
- platform: template
name: "Tap TDS"
id: tapTDS
icon: "hass:water-opacity"
unit_of_measurement: 'PPM'
accuracy_decimals: 0
update_interval: 120s
lambda: return (133.42*(id(taptds_tcv).state)*(id(taptds_tcv).state)*(id(taptds_tcv).state) - 255.86*(id(taptds_tcv).state)*(id(taptds_tcv).state) + 857.39*(id(taptds_tcv).state))*0.5;
- platform: adc
pin: GPIO4
name: "Pre-DI TDS Raw Voltage"
id: prediTDS_raw
update_interval: 120s
unit_of_measurement: "V"
icon: "mdi:water-percent"
internal: true
# Temperature Compensated Voltage
- platform: template
name: "prediTDS TCV"
id: preditds_tcv
unit_of_measurement: 'v'
accuracy_decimals: 3
lambda: 'return ((id(prediTDS_raw).state) / (1 + (0.02 * ((id(aquarium_temperature).state) - 25.0))));'
update_interval: 120s
internal: true
# Temperature Compensated TDS
- platform: template
name: "Pre-DI TDS"
id: prediTDS
icon: "hass:water-opacity"
unit_of_measurement: 'PPM'
accuracy_decimals: 0
update_interval: 120s
lambda: return (133.42*(id(preditds_tcv).state)*(id(preditds_tcv).state)*(id(preditds_tcv).state) - 255.86*(id(preditds_tcv).state)*(id(preditds_tcv).state) + 857.39*(id(preditds_tcv).state))*0.5;
- platform: adc
pin: GPIO13
name: "Output TDS Raw Voltage"
id: outTDS_raw
update_interval: 120s
unit_of_measurement: "V"
icon: "mdi:water-percent"
internal: true
# Temperature Compensated Voltage
- platform: template
name: "outTDS TCV"
id: outtds_tcv
unit_of_measurement: 'v'
accuracy_decimals: 3
lambda: 'return ((id(outTDS_raw).state) / (1 + (0.02 * ((id(aquarium_temperature).state) - 25.0))));'
update_interval: 120s
internal: true
# Temperature Compensated TDS
- platform: template
name: "Output TDS"
id: outTDS
icon: "hass:water-opacity"
unit_of_measurement: 'PPM'
accuracy_decimals: 0
update_interval: 120s
lambda: return (133.42*(id(outtds_tcv).state)*(id(outtds_tcv).state)*(id(outtds_tcv).state) - 255.86*(id(outtds_tcv).state)*(id(outtds_tcv).state) + 857.39*(id(outtds_tcv).state))*0.5;
Hi I have an issue with the TDS using ESP32 and ADS1115 and the code used above. I get an error on compiling that there is no state member meaning it fails to call the ADS channel raw value. I just don’t get that. Any help appreciated.
sensor:
- platform: dallas_temp
#address:
name: “Mixing tank water temperature”
id: mixing_tank_temperature - platform: ads1115
ads1115_id: ec_raw_v
update_interval: 120s
unit_of_measurement: V
accuracy_decimals: 3
multiplexer: ‘A0_GND’
gain: 6.144
name: “ADS1115_EC Channel A0-GND”
Temperature Compensated Voltage
- platform: template
name: “EC TCV”
id: ec_tcv
unit_of_measurement: ‘v’
accuracy_decimals: 3
lambda: ‘return ((id(ec_raw_v).state) / (1 + (0.02 * ((id(mixing_tank_temperature).state) - 25.0))));’
update_interval: 120s
internal: true
Hi.
Why did you use ADS1115 instead of ESP ADC? I’m trying to read ESP ADC input voltage but it jumps randomly from 0,300V TO 0,450V. The ADC input voltage is stable (0,438V) according to my multimeter and osciloscope.
Is this ESP32 ADC issue as suggested on link bellow?
Thank you