Operating Sequence
1. The unit should be powered up with the 'Trig' input at 0 volts (LOW)
2. The 'Echo' output will be at 0 volts (LOW)
3. The operating sequence will start when a positive pulse (HIGH) of at least 10us is applied to the 'Trig' input
4. The module will transmit a bust of eight 40KHz pulses
5. After the transmit sequence ends the 'Echo' output will go HIGH
6. If an echo is received the 'Echo' signal will go LOW. The length of the pulse will be proportional to the distance of the detected echo.
7. If no echo is received the 'Echo' output will go LOW after 38ms.
Distance calculation:-
Pulse width (uS)/58= Distance (cm)
Note:-
To avoid erratic operation always connect all four connections before powering up the module.
