After scouring GitHub, Hackaday, and Chinese forums, the answer is no. There is no official v2.0 datasheet. The YL-105 is a victim of its own success — so cheap that manufacturers don't bother with documentation.
However, you can build a better datasheet yourself. By following the calibration, hardware mods, and code above, you have essentially created a custom technical reference that outperforms any factory document.
Final Recommendation: Use the YL-105 for non-critical projects (plant watering alerts, greenhouse monitoring). For medical, scientific, or industrial applications, switch to a sensor with a genuine datasheet (e.g., Sensirion SHT85 or VH400). But if you are stuck with a box of YL-105s, the "better" datasheet is the one you just read. yl105 datasheet better
While 9600 is standard, some modules ship with different default baud rates (1200, 2400, or 115200). If you see garbage characters in the Serial Monitor (e.g., �), your baud rates do not match. Try changing mySerial.begin(9600); to other standard rates to see if the data clears up.
The YL-105 datasheet never mentions copper oxide formation. Over 48 hours, copper develops a patina that alters the dielectric baseline. A better approach: After scouring GitHub, Hackaday, and Chinese forums, the
Datasheets are crucial documents provided by manufacturers that detail the specifications, characteristics, and sometimes application notes for electronic components. When comparing datasheets, especially for a component like the YL105 (which could refer to a specific electronic part, e.g., a connector, a semiconductor, etc.), consider the following aspects:
Most YL-105 datasheets omit dynamic timing. Yet, for sequencing or pulse-width modulation (PWM) control, this is fatal. Using a digital oscilloscope, a better datasheet would report: Why does this matter
Why does this matter? If you are toggling the relay faster than 50Hz, it will fail. If you are switching AC loads without zero-crossing detection, the bounce can cause arcing. A thoughtful datasheet would include a waveform diagram showing the relationship between the IN pulse, the coil voltage, and the contact closure, including bounce artifacts.
The YL-105 is commonly known as a Rain / Water / Moisture Sensor Module. It detects water or moisture levels and outputs both:
It’s widely used in:
The most common search comparison is YL105 vs. DHT11. On paper, they look identical. In practice, the YL105 wins for three reasons.