HC-SR04 Ultrasonic Distance Measurement Control Module

The HC-SR04 Ultrasonic Distance Measurement Control Module automates the use of the HC-SR04 Ultrasonic Range Finder and other ultrasonic modules and provides a direct readout of the distance as well as the measurement in centimeters over a serial port.

Features:

• Plug-in port for HC-SR04 Ultrasonic Range Finder module
• Also compatible with other ultrasonic modules as noted below.
• Built-in microcontroller automates distance measurement
• Built-in 3-digit display shows distance in centimeters
• 5V operation

This small module includes a built-in microcontroller and 3-digit LED display. Just plug the HC-SR04 Ultrasonic module into the female header and apply 5V and ground. The module will now display the distance in centimeters. The HC-SR04 is good for about 2 to 400cm detection distance which is about 1″ to 13 feet and the display updates the distance every second.

The module also sends the distance data out a serial pin in the format of ‘D:XXX‘ where XXX is the distance in centimeters. The data is sent every second at a baud rate of 9600 and this pin can be monitored by a serial port on an MCU if desired as shown in our example below.

The module has several uses. One is simply to easily test HC-SR04 Ultrasonic modules without having to wire them up to an MCU. Another is to provide a display of the distance data such as when using the HC-SR04 on a robotic vehicle and you want an easy way to monitor the distance that the HC-SR04 thinks it is seeing.

Use with Other Ultrasonic Modules:
The module has a 4-pin header designed for use with the HC-SR04, but it can be adapted for use with other ultrasonic modules that use the same basic ping interface including the US-100 and HY-SRF05.

US-100:

• To use with the US-100, remove the jumper on the US-100 module. This puts the module in the ping interface mode rather than serial mode.
• Insert the 5-pin US-100 header into the 4-pin female header so that the extra GND pin on the one end is left unconnected. Since the module has two GND pins it is not needed.

HY-SRF05:

• To use with the HY-SRF05, you need to remove the resistor R9 on the back of the HY-SRF05 module. This isolates the OUT pin which is not normally used.
• Short the OUT pin to the adjacent GND pin.
• insert the 5-pin HY-SRF05 header into the 4-pin female header so that the original GND pin is left unconnected. Ground is now supplied through the OUT pin which is now connected to the GND pin.

JSN-SR04T:

• This module is not compatible with the JSN-SR04T waterproof range finder. The JSN-SR04T requires a longer Trigger pulse of approximately 20uS and this module outputs a 14uS Trigger pulse that results in erroneous readings.

Module Connections:
There is a 4-pin female header on the assembly for plugging in the HC-SR04 ultrasonic sensor. The sensor is inserted so that it points away from the LED display.

Power and ground can be supplied via the 6-pin male header as shown below or by connecting to the 2-pin JST XH style connector on the board. Observe the polarity markings on the board if using the JST connector.

1 x 6 Male Header:

• VCC – Connect to 5V
• TX – Transmit Data. Connect to a serial RX pin on an MCU to monitor serial output
• RX – Receive Data. Not used
• DIO / NRST– No connection. Module pin may be marked with either name
• CLK / SWIM – No connection. Module pin may be marked with either name
• GND – Ground. This ground needs to be in common with MCU if one is used.

Package Includes:

1 x HC-SR04 Ultrasonic Distance Measurement Control Module