The RRF4 Timing diagram is shown below. You only need to supply a short 10uS pulse to the trigger input to start the ranging. The RRF4 will send out an 8 cycle burst of ultrasound at 40khz and raise its echo line high. It then listens for an echo, and as soon as it detects one it lowers the echo line again. The echo line is therefore a pulse whose width is proportional to the distance to the object. By timing the pulse it is possible to calculate the range in inches/centimeters or anything else. If nothing is detected then the RRF4 will lower its echo line anyway after about 36mS.
RRF4 ultrasonic display module using microcontroller with an external serial download side, the two switch outputs, three key choices, two IO port expansion, but also special connection DS18B20 left side (for temperature compensation).
8th December 2012
Pusat robot kit, electronic kit, aksesoris harga murah (user, reseller masuk)
