ESPHome-based irrigation controller for two zones, single pump and up to 6 valves
The controller is capable of working without persistent connection with Home Assistant. That is, Home Assistant is only used as the UI (and possibly automations) but does not perform actual operations including scheduling and valve management.
Looking for alternatives to replace old K-Rain offline controller author found 8 relay controller for Raspberry Pi Pico and decided to use it for the new controller.
In fact, there are multiple irrigation controller implementations for ESPHome and Home Assistant - the implementation is intended to be simple enough and introduce no new UI controlling it, as well as requiring no persistent connectivity with Home Assistant. The Home Assistant instance could even be coming online only when changes to controller configuration are needed.
- Two zone groups
- Lawn with 3 zones
- Flowerbed with 2 zones
- Single pump with water tank
- Valve on the inlet pipe to refill the tank
Optionally you could add LCD display to see controller status and RTC to provide accurate clock.
Following Home Assistant entities are exposed by the controller:
- ESPHome
- Sprinkler component is the key to the functionality
- Dynamic 'on-time' component is
to allow changing schedules without recompiling the firmware (as with
on_timetrigger for time components)
NOTE 1 Author is not affiliated with the hardware vendors below, that is what I used to build the controller.
NOTE 2 There are no strict requirements to use Raspberry Pi Pico - ESP8266/ESP32 would also work given it has sufficient GPIOs via an extender and configuration modifications to change GPIO pins.
- Raspberry Pi Pico W
- Industrial 8-Channel Relay Module for Raspberry Pi Pico (Pico-Relay-B)
- A 5V power supply, Meanwell HDR-15-5 (5V, 2.4A, DIN rail mounted) has been used
- Irrigation (valves, pipe, pump, water tank) - likely very specific to this implementation, though the solution could be adjusted accordingly
Optionally:
- A DS3231 RTC. DS1307 would also work but has lower accuracy and is a 5V unit (most of Raspberry Pi Pico pins are 3.3V)
- A PCD8544 display
| GPIO | Purpose | In stock Pico-Relay-B |
|---|---|---|
| GPIO21 | Relay 1 (lawn, south zone) | Y |
| GPIO20 | Relay 2 (lawn, north zone) | Y |
| GPIO19 | Relay 3 (lawn, west zone) | Y |
| GPIO18 | Relay 4 (flowerbed, south zone) | Y |
| GPIO17 | Relay 5 (flowerbed, west zone) | Y |
| GPIO16 | Relay 6 (not used) | Y |
| GPIO15 | Relay 7 (water tank refill valve) | Y |
| GPIO14 | Relay 8 (water pump) | Y |
| GPIO13 | RGB LED | Y |
| GPIO6 | Buzzer | Y |
| GPIO0 | Rain sensor | N |
| GPIO1 | Water tank empty sensor | N |
| GPIO4 | Input (not used) | N |
| GPIO5 | Input (not used) | N |
| GPIO2 | PCD8544 CLK | N |
| GPIO3 | PCD8544 MOSI | N |
| GPIO22 | PCD8544 Backlight | N |
| GPIO7 | PCD8544 Reset | N |
| GPIO10 | PCD8544 CS | N |
| GPIO11 | PCD8544 DC | N |
| GPIO8 | RTC SDA | N |
| GPIO9 | RTC SCL | N |
The stock Pico-Relay-B lacks GPIO exposed via a terminal - those are needed to connect rain sensor and water tank empty one, the screw terminal (4 pins) has been added (lower left corner).
Also, the hardware initially had no RTC, DS3231 has been added (top left corner).
Finally, PCD8544 display has been added to show controller state (not shown on the image below).
Include following fragment to your ESPHome configuration (sprinkler name of
the package could be anything), it is recommended to use specific release
version (see
Releases) to
ensure your configuration is stable over the time.
A temperature sensor is a prerequisite to the configuration, its ID should be
passed via temperature_sensor_id substitution - it is only used by display
component currently.
substitutions:
temperature_sensor_id: temperature_sensor
sensor:
- platform: internal_temperature
id: ${temperature_sensor_id}
name: "Internal Temperature"
icon: "mdi:thermometer"
entity_category: diagnostic
update_interval: 60s
packages:
sprinkler: github://hostcc/esphome-config-sprinkler/main.yaml@<release version>The configuration could further be adjusted using substitutions, see main.yaml for details.
You can also remove certain portions of the configuration marked as Optional
in main.yaml if you don't have particular hardware or need to use that
functionality.
TBD