Keyestudio 4WD Manual page 290

www.keyestudio.com
The propagation speed of sound in the air is about 340m/s, therefore,
distance = speed * time, because the ultrasonic wave emits and comes
back, which is 2 times of distance, so it needs to be divided by 2, the
distance measured by ultrasonic wave = (speed * time)/2
(3)Parameters:
 Working voltage: 3-5.5V (DC)
 Working current: 15mA
 Working frequency: 40khz
 Maximum detection distance: about 3m
 Minimum detection distance: 2-3cm
 Precision: up to 0.2cm
 Sensing angle: less than 15 degrees
 Input trigger pulse: 10us TTL level
 Output echo signal: output TTL level signal (high), proportional to range
(4)Experimental Preparation：
 Insert micro:bit board into slot of keyestudio 4WD Mecanum Robot Car
 Place batteries into battery holder
 Dial power switch to ON end
 Connect micro:bit to computer by USB cable
 Open online Makecode editor
290