Is RS485 NPK Soil Sensor (EC/Temp/Moisture) Compatible with Home Assistant (ESPHome)?
Electrical Specifications
Always confirm pin assignments against the manufacturer datasheet before wiring.
Compatibility Overview
Industrial 7-in-1 soil quality probe measuring soil NPK nutrients electrical conductivity temperature and moisture via Modbus RS485.
Wiring
Host connections for this device
Technical Specification Matrix
| Feature / Attribute | Specification / Status |
|---|---|
| Hardware Protocol | Modbus RS485 / 3.3V to 5V |
| Bridge Required | NO |
| Border Router Needed | None |
| Hardware Capabilities & Peripherals | Soil Nitrogen (mg/kg) Phosphorus (mg/kg) Potassium (mg/kg) EC Conductivity Note: these entities come from the ESPHome configuration you flash — each one needs its matching component in that YAML before it appears. |
| Pairing Complexity | Advanced |
| Factory Reset Instruction | Hold BOOT button for 3s. |
Wire, Flash, Adopt, Check
Wire it up
Follow the bus reference above. The host pins in the configuration are defaults — any free GPIO of the right kind will do, as long as the YAML names the pin you actually used.
Flash the configuration
Create a new device in the ESPHome dashboard (the Home Assistant add-on) and paste the configuration below into it, or save it as emb_esp32_soil_ec_ha.yaml and run esphome run emb_esp32_soil_ec_ha.yaml. The first flash goes over USB. If it is not detected, hold BOOT button for 3s to put it in download mode. Every update after that is over the air.
Adopt it in Home Assistant
Settings → Devices & Services. A node on the same network shows up as a discovered ESPHome device within a minute of joining Wi-Fi; choose Configure and enter the API encryption key from your secrets.yaml. If discovery does not find it, add the ESPHome integration by hand with the node's IP address.
Check it works
The entities on this page appear under the device in Home Assistant and update at the configured interval. The ESPHome log (Logs in the dashboard, or esphome logs) reports the setup of each component and any bus scan results at boot.
ESPHome Configuration
Starting configuration for RS485 NPK Soil Sensor (EC/Temp/Moisture) on ESP32. Untested on hardware — verify wiring and pins against your own board.
# ESPHome configuration for RS485 NPK Soil Sensor (EC/Temp/Moisture)
# Host: ESP32. Pin numbers below are host-side defaults — any free
# GPIO will do, and you should change them to match your own wiring.
esphome:
name: emb_esp32_soil_ec_ha
friendly_name: "RS485 NPK Soil Sensor (EC/Temp/Moisture)"
esp32:
board: esp32dev
framework:
type: esp-idf
logger:
api:
encryption:
key: !secret api_encryption_key
ota:
- platform: esphome
password: !secret ota_password
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
uart:
rx_pin: GPIO16
tx_pin: GPIO17
baud_rate: 9600
# JXCT 7-in-1 register map: holding registers from 0x0000, one per value.
# The probe ships at Modbus address 1, 9600 8N1. DE and RE on the MAX485
# board are tied together and driven by flow_control_pin.
modbus:
flow_control_pin: GPIO5
modbus_controller:
- id: soil_probe
address: 0x01
update_interval: 60s
sensor:
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Soil Moisture"
register_type: holding
address: 0x0000
value_type: U_WORD
unit_of_measurement: "%"
accuracy_decimals: 1
filters:
- multiply: 0.1
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Soil Temperature"
register_type: holding
address: 0x0001
value_type: S_WORD
unit_of_measurement: "°C"
accuracy_decimals: 1
filters:
- multiply: 0.1
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Soil Conductivity"
register_type: holding
address: 0x0002
value_type: U_WORD
unit_of_measurement: "µS/cm"
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Soil pH"
register_type: holding
address: 0x0003
value_type: U_WORD
accuracy_decimals: 1
filters:
- multiply: 0.1
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Nitrogen"
register_type: holding
address: 0x0004
value_type: U_WORD
unit_of_measurement: "mg/kg"
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Phosphorus"
register_type: holding
address: 0x0005
value_type: U_WORD
unit_of_measurement: "mg/kg"
- platform: modbus_controller
modbus_controller_id: soil_probe
name: "Potassium"
register_type: holding
address: 0x0006
value_type: U_WORD
unit_of_measurement: "mg/kg"
Before you flash:
the !secret values come from your
secrets.yaml, and the GPIO numbers are host-side
defaults rather than properties of this part — change them to match how you actually wired it.
Report a Pinout Error or Submit Tested Code Snippets
Found a pin mapping quirk or built a custom ESPHome YAML driver for RS485 NPK Soil Sensor (EC/Temp/Moisture)? Submit a pull request or report corrections to our index.