This HC-SR04 ultrasonic module can realize 2 ~ 700cm of non-contact ranging function, has 5 V of wide voltage input range, static power consumption is less than 3mA. Their  own temperature sensor will revise the ranging and has many communication modes like GPIO, just like watchdog inside, very stable and compact.

Module main technical parameters are as under;

• Working Voltage : 5V(DC)
• Static current: Less than 2mA.
• Output signal: Electric frequency signal, high level 5V, low level 0V.
• Sensor angle: Not more than 15 degrees.
• Detection distance: 2cm-450cm.
• High precision: Up to 0.3cm
• Input trigger signal: 10us TTL impulse
• Echo signal : output TTL PWL signal
• Pin out connection: 1.VCC 2.trig(T) 3.echo(R) 4.GND