This post is intended to help users who use the ultrasonic interface card (The serial adapter for ultrasonic sensor HCSR-04) manufactured by Elementz engineers guild Pvt Ltd. You may often find using the ultrasonic sensor, the whole triggering and listening for the echo thing, a little bit confusing. The Serial adapter for HCSR-04 gives the distance measured directly as a serial output.
There are two jumpers J1 and J2 in the adapter card. J1 is the baud rate select jumper and J2 is the Unit select jumper. The figure below shows the values of baud rate and unit according to the position of the respective jumpers.
The baud rates offered are 9600 and 57600 bits/sec and the output units are in inch or in cm. The pins used for connecting to supply and to take outputs are marked in below figure.
The output is in serial format ending with newline and carriage return characters. The firmware update pins are used for factory purposes and is of no use to the user. The extra VCC and GND pin can be used if needed.