Zero false alarm rate, Real-time response Correct data Minimum distinguishable particle diameter: 0.3 micrometer High anti-interference performance due to the patented six-sided shielding structure Optional direction of air inlet and outlet to adapt to different designs PIN1: VCC power supply 5V PIN2: GND power ground PIN3: NC PIN4: RXD: Serial port receiving pin (3.3V level) PIN5: TXD: Serial port sending pin (3.3V level) PIN6: RESET is suspended during use. Lowering will cause the module to malfunction PIN7: NC PIN8: PWM: PWM pulse width signal output pin (3.3V level) Circuit design: 1) D9 requires 5V power supply because the fan requires 5V drive. Other data communication and control pins require 3.3V as the high level. Therefore, the main board MCU connected for communication should be powered by 3.3V. If the motherboard MCU is powered by 5V, a level conversion chip or circuit should be added to the communication lines (RXD, TXD) and control lines (SET, RESET). 2) For serial output, only connect PIN1, PIN2, and PIN5; other pins do not need to be connected 3) For PWM output, only connect PIN1, PIN2, and PIN8; other pins do not need to be connected Color: Silver Material: Metal Package Contents: 1 x Sensor Module Note: Light reflection and different displays may cause slight color differences compared to the actual item. Measurement error allowance is +/- 1-3 cm.