SunFounder 3in1 Kit
• 8. Self-Driving Car (Car Project)
• 7. Current Limiting Gate (IoT Project)
1.28 Ultrasonic Module
Ultrasonic ranging module provides 2cm - 400cm non-contact measurement function, and the ranging accuracy can
reach to 3mm. It can ensure that the signal is stable within 5m, and the signal is gradually weakened after 5m, till the
7m position disappears.
The module includes ultrasonic transmitters, receiver and control circuit. The basic principles are as follows:
1. Use an IO flip-flop to process a high level signal of at least 10us.
2. The module automatically sends eight 40khz and detects if there is a pulse signal return.
3. If the signal returns, passing the high level, the high output IO duration is the time from the transmission of the
ultrasonic wave to the return of it. Here, test distance = (high time x sound speed (340 m / s) / 2.
The timing diagram is shown below.
50 Chapter 1. Components List and Introduction
To Next Page
Loading...
