Yl105 Datasheet Better [extra Quality] -

While many YL-105 boards accept 5V on VCC, the data pins (TX/RX) are often 3.3V logic. If you are using a 5V Arduino (Uno/Nano), it is safest to use a logic level converter or a voltage divider on the RX pin of the module to prevent damage.

. The LDO regulator requires a "dropout" margin to function. yl105 datasheet better

SoftwareSerial mySerial(2, 3); // RX, TX While many YL-105 boards accept 5V on VCC,

Stop fiddling with external pull-ups and faulty libraries. Download the original YL105 datasheet, follow the timing diagrams above, and build humidity logging that just works. follow the timing diagrams above

: Clear labeling of VCC, GND, and data pins to prevent short circuits.