1. Product Overview
The Yieryi 8-in-1 Smart Soil NPK Sensor is a versatile device designed for comprehensive soil analysis. It measures 8 key parameters: Soil Temperature, Soil Moisture, Soil EC (Electrical Conductivity), Soil Salinity, Soil pH, Soil Nitrogen (N), Soil Phosphorus (P), and Soil Potassium (K). This smart device connects directly to your Android or HarmonyOS smartphone via USB, providing real-time data monitoring and logging capabilities, making it ideal for precision agriculture, home gardening, greenhouse management, and various other planting applications.
The sensor features durable 316L stainless steel probes and an IP68 waterproof and dustproof rating, ensuring reliable performance and longevity in various soil conditions. Data can be easily exported for analysis and record-keeping.
2. Setup Guide
2.1. App Download and Installation
- Scan the QR code provided on the product packaging or in the manual to download the companion application.
- The app is compatible with Android and HarmonyOS systems only. It does not support iOS devices.
- If your phone blocks the app installation, you may need to adjust your security settings:
- Go to Settings → Security and privacy → Install unknown apps.
- Select the app you use to download (e.g., Chrome or My Files).
- Turn on Allow from this source.
- Then, reopen the APK file to install.
- After the download completes, click to authorize the installation.
2.2. Enabling OTG Function
For the sensor to communicate with your phone, the OTG (On-The-Go) function must be enabled. Most phones enable OTG automatically, but some require manual activation.
- Go to your phone's Settings.
- Search for "OTG" in the settings search bar.
- Locate the OTG setting and toggle it ON. Note that OTG may automatically turn off after 10 minutes of inactivity on some devices.
2.3. Connecting the Sensor
- Connect the sensor's USB cable to the provided OTG adapter.
- Plug the OTG adapter into your smartphone's charging port.
- Open the installed "Data Monitoring" app.
- When prompted, allow the app to access USB Serial by tapping "OK".
- The app should now display real-time soil data.
Video 1: Step-by-step guide on connecting the sensor and enabling OTG.
3. Operating Instructions
3.1. Measurement Methods
The sensor supports two primary measurement methods:
- Rapid Measurement Method: Select a suitable measurement location, avoiding rocks and similar hard objects. Excavate the surface soil to the required measurement depth, maintain the original looseness of the soil below, grip the sensor tightly, insert it vertically into the soil, and do not shake it left or right during insertion. It is recommended to calculate the average of multiple readings within a small range of one measurement point.
- Buried Surveying Method: Dig a pit with a diameter greater than 20cm vertically, and insert the sensor steel needle into the pit according to the measurement needs. Fill and compact the pit to ensure the steel needle is in close contact with the soil. After the sensor stabilizes for a period of time, continuous long-term measurement and recording can be carried out.
3.2. Real-time Data Monitoring
Once connected, the app will display real-time readings for all 8 soil parameters. You can view the data in various modes within the app interface.
3.3. Data Storage and Export
The app supports data storage and export functions. You can save the current real-time data locally on your phone and export it in Excel format for further analysis and record-keeping.
4. Maintenance
Proper maintenance ensures the longevity and accuracy of your soil sensor.
- Probe Cleaning: After each use, especially when measuring parameters like pH, conductivity, nitrogen, phosphorus, and potassium, thoroughly clean the probes. One of the four probes has a dark color and is prone to wear and tear; ensure this probe is also cleaned carefully.
- Environmental Protection: Avoid direct exposure of the transmitter to strong sunlight, which may cause excessive temperature. Pay attention to lightning protection when using outdoors.
- Water Immersion: The transmitter has an IP68 protection level and can be completely submerged in water if necessary, but it is designed for soil testing, not water testing.
5. Troubleshooting
- Q: The Nitrogen reading is always 0. How can I fix this?
A: This usually happens when the soil is too dry. Please add some water to the soil and test again to get an accurate Nitrogen reading. - Q: The app says “Connection failed” when I insert the sensor.
A: This is usually because OTG (On-The-Go) is not enabled on your phone. Most phones enable OTG automatically, but some require you to turn it on manually. To enable OTG, go to: Settings → Other Settings → OTG. If you can't find it, search online for instructions specific to your phone model. Once enabled, reconnect the sensor and it will work normally. - Q: The app can’t save my measurement data.
A: Please check if your system has disabled the app's storage permission. If so, enable the app’s storage function in your phone's settings. - Q: Can I use the app with an iPhone?
A: No, the app is currently compatible only with Android and HarmonyOS devices. - Q: Can I test the sensor in water?
A: No, the sensor is designed specifically for soil testing and should only be used in soil. - Q: Is the sensor safe to leave in the soil during rain?
A: Yes, the sensor has an IP68 waterproof rating, making it safe to leave in the soil even during rain.
6. Specifications
| Parameter | Range | Resolution | Accuracy |
|---|---|---|---|
| Power Supply | DC 5V (via USB) | ||
| Max Power Consumption | 0.5W | ||
| Operating Temperature | -20°C ~ +60°C | ||
| Output Signal | USB interface | ||
| Cable Length | 2 meters | ||
| Dimensions | 128mm x 46mm x 16mm | ||
| Protection Grade | IP68 waterproof & dustproof | ||
| Probe Material | 316L Stainless Steel | ||
| Soil pH | 3~10 pH | 0.1 | ±0.2 |
| Soil EC | 0~20000 μS/cm | 10 μS/cm | ±3% |
| Soil Salinity | 0~20000 mg/L | 1 mg/L | ±3% |
| Soil Moisture | 0~100% (m³/m³) | 0.1% | ±3% |
| Soil Temperature | -40~80°C | 0.1°C | ±0.3°C (@25°C) |
| Soil NPK | 0~1999 mg/kg | 1 mg/kg | ±3% |
7. User Tips
- For accurate NPK readings, ensure the soil is adequately moist. Dry soil can lead to inaccurate or zero readings for nitrogen.
- When performing rapid measurements, avoid disturbing the soil structure excessively to get a representative reading.
- Regularly check your phone's OTG settings, as some devices may automatically disable it after a period of inactivity.
- Always clean the probes thoroughly after each use to prevent residue buildup and maintain measurement accuracy.
8. Warranty and Support
For any product-related inquiries, technical support, or warranty claims, please contact the Yieryi Official Store directly. Ensure you retain your purchase receipt as proof of purchase. The product is certified with CE, indicating compliance with European safety, health, and environmental protection standards.
