Mod-pH for Home Assistant

In this write-up, we will install ESPHome to get pH measurements into Home Assistant.

• We will be working in a terminal and using a few commands
• You'll need a Home Assistant installation running
• An ESP-device
• A Mod-pH module and preferably a carrier board

These instructions are for the CLI version of ESPHome. You can also copy and paste the YAML into the ESPHome addon within Home Assistant and avoid the CLI completely.

1.

📦 Install ESPHome

2.

🏁 Start a project

3.

🔌 Connections

• Module only
  

  Module	Controller
  GND	ground
  VCC	3.3 - 5 volt power supply
  SCL	SCL
  SDA	SDA
  PROBE_1	input probe wire
  PROBE_2	reference probe wire

• Carrier Board
  

  Carrier Board	Controller
  GND	ground
  VIN	3.3 - 5 volt power supply
  SCL	SCL
  SDA	SDA
  1W	optional 1-wire device signal line
  EN	optional EN wire, drive HIGH to disable both power modules

  Carrier 1W Header	1-Wire Sensor
  GND	ground
  VCC	3.3 - 5 volt power supply
  SIG	signal data line for 1-Wire sensor

  
  Probe connection is made with the SMA connector, using a SMA-BNC Bulkhead or similar.

We'll use an external sensor component to get the Mod-pH module working. This is done by adding some lines to the YAML.

The YAML file should be changed to the following:

substitutions:

  friendly_name: Microfire Mod-pH

  device_name: microfire-mod-ph

esphome:

  name: $device_name

esp32:

  board: esp32dev

  framework:

    type: arduino

logger:

api:

ota:

wifi:

  ssid: !secret wifi_ssid

  password: !secret wifi_password

  ap:

    ssid: $device_name

    password: !secret wifi_failover

captive_portal:

# import the mod-ph component

external_components:

  - source:

      type: git

      url: https://github.com/u-fire/ESPHomeComponents/

# https://esphome.io/components/i2c.html

i2c:

  sda: 21

  scl: 22

sensor:

  - platform: mod_ph

    id: ph

    name: pH

    update_interval: 15s

button:

  - platform: template

    id: ph_calibrate_low

    name: pH Calibrate Low 4.0

    icon: mdi:format-vertical-align-bottom

    on_press:

        lambda: |-

          id(ph).calibrateLow(4.0);

  - platform: template

    id: ph_calibrate_mid

    name: pH Calibrate Mid 7.0

    icon: mdi:format-vertical-align-center

    on_press:

        lambda: |-

          id(ph).calibrateMid(7.0);

  - platform: template

    id: ph_calibrate_high

    name: pH Calibrate High 10.0

    icon: mdi:format-vertical-align-top

    on_press:

        lambda: |-

          id(ph).calibrateHigh(10.0);

  - platform: template

    id: ph_calibrate_reset

    name: pH Calibrate Reset

    icon: mdi:restore

    on_press:

        lambda: |-

          id(ph).calibrateReset();

  - platform: factory_reset

    name: Restart with Factory Default Settings

Make sure you change the wifi section to your network and password if you aren't using a secrets.yaml. Check that the i2c section is using the correct pins.

5.

➡️ Upload

Type esphome run mod-ph.yaml Copied!. It will compile the project and ask you which serial device to upload the code to. After that, you'll see the ESP debug output. If everything goes to plan, you should see a device has been discovered in Home Assistant.

6.

🏠 Home Assistant

From within Home Assistant, press Settings > Devices & Services and find the device in the ESPHome integration box. Click it and then click where it says 1 Device. You should see a screen with all the information, Mod-pH measurement, and some buttons to calibrate and reset the device. You can create dashboards, scripts, and anything else Home Assistant can do from here.

There is more documentation and examples for various combinations of sensors/modules on our ESPHomeComponents GitHub repo