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Wireless "SOILSENS-V5W" and Wired "SOILSENS-V5"
The SOILSENS-V5W is a wireless capacitive soil moisture sensor that supports both ESP-NOW and Wi-Fi connectivity. It also measures soil temperature, air temperature, air humidity, and ambient light. The capacitive sensing electrodes are embedded inside the PCB, which helps protect them from direct exposure. The sensor is compact, power-efficient, and designed for long-range communication in ESP-NOW mode. It can be configured without reflashing and supports MQTT auto-discovery through CapiBridge or direct Wi-Fi MQTT integration, making it fully compatible with Home Assistant.
🛒 Where to Buy https://www.PricelessToolkit.com
- 18.04.2026 - Improved configuration portal and calibration workflow.
-
- Added a cleaner configuration-only web UI with simpler setup for ESP-NOW, Fast-WIFI, and Basic-WIFI.
-
- Added web-based soil calibration with live raw value preview plus dedicated Dry Soil and Wet Soil capture buttons.
-
- Added Reset to Default directly inside the web interface, making recovery and reconfiguration easier.
- 12.03.2026 - Bugfix / compatibility update.
-
- Fixed compilation for ESP32 Arduino Core v3.3.7 and AHT20 v1.0.2.
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- Tested with ArduinoJson v7.4.3, PubSubClient v2.8, and SparkFun TMP102 Breakout v1.1.2.
- 14.05.2025 - Added FailSafe, if it can't connect to WIFI or MQTT, it will power off after 15s.
- 21.03.2025 - Added Basic WIFI mode.
- Microcontroller:
- ESP32-C3
- Sensors:
- Soil Temperature: TMP102
- Air Temperature and Humidity: AHT20
- Light Sensor: ALS-PT19-315C
- Soil Moisture: PCB Trace in the internal layer
- Power:
- Uses a 1S LiPo battery with a PH2.0 connector
- Requires an external 1S LiPo charger
- Buttons:
- PRG (Programming)
- RST (Reset)
- CAL (Calibration)
- TRG (Trigger)
- LED Indicators:
- Green LED: Power indicator
- Blue LED: Configuration mode indicator
- Sensor Reading Interval:
- Default: 1 hour
- Configurable: 5m, 10m, 30m, 1h, and 2h
- Configuration Method: Adjustable via onboard PCB solder jumpers
- 1S 250mAh or less LiPo Battery (Connector PH2.0) 35x20x4mm MAX.
Warning
Note
Lipo Polarity explanation "Adafruit Video" https://youtu.be/ILArrTIMFyM?si=WlTsnVo7XTozZ2FT
- 1S 4.20V LiPo charger.
- PricelessToolkit Micro-Charger
- Adafruit Micro Lipo
Warning
- Aliexpress
- PricelessToolkit
- SOILSENS-V5W supports
ESP-NOWandWi-Fioperation. - By default, the sensor starts in ESP-NOW mode.
- In this default mode, no initial setup is required if you are using a compatible CapiBridge gateway.
- The default gateway key is
xy.
| Feature | ESP-NOW | Fast-WIFI | Basic-WIFI |
|---|---|---|---|
| Energy Efficiency | Highly energy-efficient | ~3x Higher power consumption | ~10+x Higher power consumption |
| Range | Long-Range | Short range | Short range |
| Configuration | Does not require configuration | Requires network and MQTT configuration | Requires network and MQTT configuration |
| Broadcasting | Sensor data can be read from a third device without connecting to a network | Requires connection to a network | Requires connection to a network |
| Gateway Requirement | Requires a gateway Capibridge | Does not require a gateway | Does not require a gateway |
Note
Measured using Power Profiler Kit 2, with a 250 mAh battery and a 1-hour wake-up interval.
| Parameter | ESP-NOW | Fast-WIFI | Basic-WIFI |
|---|---|---|---|
| Active Duration (seconds) | 0.55 seconds | 1.5 seconds | 1.5 - 10 seconds |
| Current During Active Phase | 40 mA | 47 mA | * |
| Energy Consumption in Active Phase | 0.006112 mAh | 0.02 mAh | * |
| Inactive Duration | 0.999847 hours | 0.99956 hours | * |
| Energy Consumption in Inactive Phase | 0.00007 mAh | 0.00007 mAh | * |
| Total Energy Consumption | 0.006182 mAh | 0.02007 mAh | * |
| Total Hours of Operation | 40,445 hours | 12,459 hours | * |
| Total Days of Operation | 1,685 days | 519 days | * |
(*) Depends on the network topology
To access the configuration settings, follow these steps:
- Enter Configuration Mode
- Press and hold the CAL button.
- While holding the CAL button, power the sensor or brefly press TRG button.
- Keep holding the CAL button for more than 2 seconds, then release it.
- The blue LED will blink, indicating that the sensor has entered configuration mode, the sensor creates a WiFi Access Point named
SOILSENS-V5W. - Disconnect Celular connection "4G/5G" and Connect to
SOILSENS-V5WWIFI hotspot. - Open a web browser and go to
http://192.168.4.1.
-
Configure the Sensor in the Web UI
- Connection Mode
- ESP-NOW: Uses direct ESP-NOW communication with the CapiBridge gateway.
- Fast-WIFI: Uses WiFi + MQTT with fixed network details for faster reconnects and lower power use than Basic-WIFI.
- Basic-WIFI: Uses standard WiFi + MQTT setup with fewer required network fields.
- Identity
- Sensor Name: Set the name that will appear in Home Assistant under MQTT.
- Gateway Key: Required only for ESP-NOW mode.
- ESP-NOW Encryption: Optional. If enabled, enter the same key used by your gateway in this format:
["0x4B","0xA3","0x3F","0x9C"]
- WiFi Access
- WiFi SSID: Enter your 2.4 GHz WiFi network name.
- Password: Enter the WiFi password.
- Fast-WIFI Network Details
- AP MAC Address: Use the radio interface MAC address of your access point.
- WiFi Channel: The channel must be fixed on the access point and must match the value entered here.
- Local IP: Use a free IP address from your local network range and reserve it for the sensor.
- Gateway / Subnet: Enter the network details that match your router.
- MQTT Broker
- Enter your MQTT server IP or hostname, port, username, and password.
- In most Home Assistant installations, the MQTT server IP is the same as the Home Assistant IP, and the port is usually
1883.
- Connection Mode
-
Save or Reset
- Click Save Configuration to store the current settings and power off the sensor.
- Click Reload Values to refresh the page and reload the currently saved values.
- Click Reset to Default to clear all saved configuration and calibration values and return to the firmware defaults.
Note
If the LED stays on after Saving configuration in WIFI mode, it means the sensor cannot connect because the SSID, Wi-Fi password, MAC address, Wi-Fi channel, or MQTT credentials are incorrect!
Accurate soil moisture readings require proper calibration. Follow these steps:
- Insert the sensor into the dry soil.
- Optional ( For best results, water the soil, wait a couple of days for the soil to settle around the sensor, and then dry out. )
- Open the web configuration page as described in the configuration section above.
- Go to the Calibration block.
- Check SOIL SENSOR RAW VALUE "LIVE" and wait until the reading is stable.
- For the dry calibration point:
- Click SET DRY SOIL.
- Click Save Configuration to store the dry calibration value.
- For the wet calibration point:
- Water the soil to the maximum moisture level you want to allow. For best accuracy, let it soak for 5 - 10 minutes.
- Reopen the web configuration page as described in the configuration section above.
- Click SET WET SOIL.
- Click Save Configuration to store both calibration values.
Note
For the best result, avoid moving the sensor during calibration. If the soil composition changes over time, or if sediment builds up around the probe, recalibration may be needed.
Important
0.
Note
Ensure the Wi-Fi signal strength at the installation point is strong and stable.
| RSSI (dBm) | Signal Quality | Description |
|---|---|---|
| -30 to -50 dBm | Excellent | Very strong signal, ideal for stable data transmission |
| -51 to -60 dBm | Good | Strong signal, generally reliable for data |
| -61 to -70 dBm | Fair | Moderate signal, some minor issues possible, but usable |
| -71 to -80 dBm | Poor | Weak signal, may experience some data drop |
| -81 to -90 dBm | Very Poor | Very weak signal, frequent data drop likely |
| Below -90 dBm | Unusable | No effective connection, likely out of range |
- Open the provided code in the Arduino IDE.
- Install all required libraries.
#include <esp_now.h>
#include <WiFi.h>
#include "driver/adc.h"
#include "esp_adc_cal.h"
#include "Wire.h"
#include <SparkFunTMP102.h>
#include <ArduinoJson.h>
#include <AHT20.h>
#include <Preferences.h>
#include <WebServer.h>
#include <PubSubClient.h>
- Select the appropriate board and port parameters. Refer to the screenshot below for the recommended settings.
-
Connect a 3.3V USB-to-TTL adapter to SOILSENS-V5W.
Sensor Pin Adapter Pin TX RX RX TX 3V3 3V3 GND GND -
Press and hold the PRG button on the sensor.
-
While holding PRG, connect the USB-to-TTL adapter to your computer.
-
Click Upload in the Arduino IDE.
Due to the capacitive sensing principle, readings can vary based on soil moisture, tightness, and insertion depth. Repeated insertions might loosen the soil, affecting subsequent readings.
| Solder Jumpers | Interval Selection |
|---|---|
 |
You can change the interval by cutting the middle of the 1H jumper and then bridging the desired jumper with solder. Available base intervals are 5m, 10m, 30m, 1h, and 2h. Different combinations are also possible. Parallel Resistor Calculator |
If you want to experiment with different wake-up intervals, you can also change the resistor value.
| Time Interval | Resistor Value (kΩ) | Time Interval | Resistor Value (kΩ) |
|---|---|---|---|
| 1 min | 22.00 | 10 min | 57.6 - soldered |
| 2 min | 29.349 | 20 min | 77.579 |
| 3 min | 34.729 | 30 min | 93.1 - soldered |
| 4 min | 39.097 | 40 min | 104.625 |
| 5 min | 42.2 - soldered | 50 min | 115.331 |
| 6 min | 46.301 | 1 h | 124.00 - soldered |
| 7 min | 49.392 | 1h 30min | 149.398 |
| 8 min | 52.224 | 2 h | 169.00 - soldered |
| 9 min | 54.902 |
Note
The default wake-up interval is 1 hour. Reducing the interval will increase energy consumption.
View schematic. Click here
The ideal case material is transparent and UV-resistant. ASA or white ABS is a good choice because it allows enough light to enter for the luminance sensor to work properly. For indoor use, translucent PETG can improve the luminance sensor range, and vent holes help the air temperature and humidity sensors work correctly. For outdoor use, a case without vent holes is recommended to reduce the risk of water ingress during heavy rain. Glue for case https://s.click.aliexpress.com/e/_DcvGBY9
- Holding the calibration button.
- More than 2 seconds opens configuration mode.
- When manually pressing the trigger button, the sensor may occasionally stay on and not power off if the button is not released quickly enough. If this happens, simply press the reset button.