Pro-Wave's SRM400 and US040 detect proximity

The Pro-Wave SRM400 sonar ranging modules and US040 sensors are used for car-reversing aids and are popular with volume manufacturers and after-market suppliers.

The SRM400 is a sonar-ranging module that utilises the PW-0268 Sonar Ranging IC, which can work with all of Pro-Wave's PT or EP-type transducers.

The SRM400 provides a time-saving shortcut for designers with limited experience of analogue design and/or the operation of ultrasonic transducers.

When developing car-reversing systems or other distance-measurement products, this ready-to-go module allows engineers to focus their efforts on the system integration, digital processing, software and mechanical design.

The Pro-Wave US040015 is an ultrasonic sensor that generates asymmetrical beam patterns, approximately +/-80 degrees about the horizontal axis and 40 degrees about the vertical, which meets the requirements of most car-reversing aids.

The US040015 has only three wires to connect; +V power, ground and I/O digital signal.

The I/O digital signal connection is a bi-directional port and provides an open collector connection with an internal pull-high resistor.

When the I/O port is being pulled low by an external switching transistor, the sensor is activated.

After predetermined excitation duration, decided by the control pulse, the I/O port will again go low if a valid echo signal is detected.

The US040015 deals effectively with all the analogue signals of proximity detection, providing a digital output for the host system.