// Datasheet threshold: 30 µs is the boundary if(duration > 30) byte *data = byte; return true;
Always refer to the manufacturer’s YL105 datasheet V1.2 for absolute maximum ratings (TMV: -20°C storage, 5.5V absolute max input).
In the crowded world of capacitive humidity sensors, the YL105 is often misunderstood. Viewed by beginners as a "cheap alternative," this sensor module—when paired with a correct reading of its datasheet—offers a superior price-to-performance ratio for 80% of DIY and commercial IoT projects. yl105 datasheet better
#define YL105_PIN 2 void startSignal() pinMode(YL105_PIN, OUTPUT); digitalWrite(YL105_PIN, LOW); delay(20); // Better: 20ms (exceeds 18ms requirement) digitalWrite(YL105_PIN, HIGH); delayMicroseconds(40); pinMode(YL105_PIN, INPUT);
| 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 | // Datasheet threshold: 30 µs is the boundary
The YL105 datasheet reveals a sensor that is better for 80% of hobbyist and commercial indoor projects . It is robust, forgiving, and cheap. When paired with proper timing code and a clean power supply, it rivals sensors twice its price.
bool readByte(uint8_t* data) uint8_t byte = 0; for (int i = 0; i < 8; i++) while(digitalRead(YL105_PIN) == LOW); // Wait for start of bit uint32_t startTime = micros(); while(digitalRead(YL105_PIN) == HIGH); uint32_t duration = micros() - startTime; When paired with proper timing code and a
When you are searching for the term you aren't just looking for pinouts and voltage ratings. You want a comparative analysis. You want to know: Why should I choose the YL105 over the DHT11, DHT22, or the AM2302?