Yl105 - Datasheet Better

Searching "yl105 datasheet better" usually means you want a replacement. Let’s compare it to two superior sensors.

Most users fail with the YL105 because they ignore the timing diagram. To make your YL105 perform better than a cheap library default, you must understand these values:

| Parameter | Symbol | Value | Your code must... | | :--- | :--- | :--- | :--- | | Start signal low time | Tbe | > 18 ms | Pull pin LOW for 20ms (not 1ms) | | Sensor response low | Trel | 80 µs | Wait for pin to go LOW | | Sensor response high | Treh | 80 µs | Wait for pin to go HIGH | | Bit "0" high time | Tbit_0 | 24-28 µs | Sample after 30 µs | | Bit "1" high time | Tbit_1 | 70-74 µs | Sample after 50 µs | yl105 datasheet better

The "Better" Tip: The datasheet is better than online tutorials because it confirms you must disable interrupts during the 40-bit read. If you use delayMicroseconds() without disabling interrupts, you will get CRC errors. Use noInterrupts() and interrupts() in Arduino, or portDISABLE_INTERRUPTS() in ESP-IDF.

The YL-105 datasheet never mentions copper oxide formation. Over 48 hours, copper develops a patina that alters the dielectric baseline. A better approach: Searching "yl105 datasheet better" usually means you want

// DO NOT DO THIS
void setup() 
  pinMode(2, OUTPUT);
  digitalWrite(2, LOW);
  delay(1); // Too short! Datasheet says 18ms minimum
  pinMode(2, INPUT);

Many engineers overlook this. The DHT11's output high voltage is 4V minimum when run at 5V—this can damage a 3.3V ESP32. The YL105 datasheet states that signal levels are TTL compatible and function reliably down to 3.3V because the onboard regulator handles the conversion.

Verdict: If you are building a battery-powered ESP8266 or ESP32 project, the YL105 is the better datasheet choice. The YL-105 datasheet never mentions copper oxide formation

Yes, for hobby projects – it’s cheap, easy to use, and gives both analog and digital outputs.
No, for professional use – lacks calibration, corrosion protection, and official documentation.

For a better experience, treat the YL-105 as a basic water presence detector, not a precise moisture meter.