Communication Protocol

Communication Command Frame Format:

Header Address Data Length Command Data Checksum
0x55 0xAA 1 byte 1 byte 1 byte Data 1~Data n

Factory parameters:

Commands List:

Read distance Read temperature Set address Set baud rate
0x02 0x03 0x55 0x08

warning_yellow.png NOTE: if you are using a RS485 protocol sensor, the USB to RS485 converter is needed in the test commands listed as below.

Read the Measured Distance

The host sends a frame command to the ultrasonic sensor through the UART(RS485) interface to trigger the sensor to start detecting, and then receives the distance value command returned by the sensor.

URM07 Distance Measurement

For example, the address of the ultrasonic sensor is 0x11, the host sends: 0x55 0xAA 0x11 0x00 0x02 0x12 [ 55 AA 11 00 02 12 ]

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Device address ----- 0x11

Data length ----- 0x00

Command --------- 0x02

Checksum ------- 0x12

The ultrasonic sensor returns data as: 0x55 0xAA 0x11 0x02 0x02 0x00 0xCA 0xDE

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Local address ----- 0x11

Data length ----- 0x02

Command --------- 0x02

Distance High ----- 0x00

Distance low ----- 0xCA (Distance value 0x00CA unit is centimeter, that is, decimal 202 cm)

Checksum ------- 0xDE

Read the Measured Temperature

The host reads the current temperature measured by the ultrasonic sensor via the UART(RS485) interface.

URM07 Temperature Measurement

For example, the ultrasonic sensor address is 0x11, the host sends: 0x55 0xAA 0x11 0x00 0x03 0x13 [ 55 AA 11 00 03 13 ]

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Device address ----- 0x11

Data length ----- 0x00

Command --------- 0x03

Checksum ------- 0x13

The ultrasonic sensor returns data as: 0x55 0xAA 0x11 0x02 0x03 0x00 0xFF 0x14

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Local address ----- 0x11

Data length ----- 0x02

Command --------- 0x03

Temperature high ----- 0x01

Temperature low ----- 0x13 (temperature value 0x0113, 27.5 degrees. Note: T = Returned value/10)

Checksum ------- 0x29

Set the Address of the Ultrasonic sensor

The host sets the ultrasonic sensor address via the UART(RS485) interface. URM07 Modify the Address

For example, set the ultrasonic sensor address 0x12, the host sends: 0x55 0xAA 0xAB 0x01 0x55 0x12 0x12 [ 55 AA AB 01 55 12 12 ]

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Device address ----- 0xAB

Data length ----- 0x01

Command --------- 0x55

Set the address ----- 0x12 (need to set the device address 0x12)

Checksum ------- 0x12

Set the success of the ultrasonic sensor return command 0x55 0xAA 0x12 0x01 0x55 0xCC 0x33

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Device address ----- 0x12 (modified device address)

Data length ----- 0x01

Command --------- 0x55

Operation status ----- 0xCC (0xCC - operation completed 0xEE - operation failed)

Checksum ------- 0x33

Set the UART(RS485) Communication Baud Rate

The host sets the ultrasonic sensor communication baud rate via the UART(RS485) interface. URM07 Modify the Baudraet

For example, if the address of the ultrasonic sensor is set to 0x11, the host sends: 0x55 0xAA 0x11 0x01 0x08 0x0B 0x24 //Set baudrate to 256000bps [ 55 AA 11 01 08 0B 24 ]

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Device address ----- 0x11

Data length ----- 0x01

Command --------- 0x08

Baud rate selection --- 0x0B

Checksum ------- 0x24

If the setting is successful, the ultrasonic sensor returns the command as: 0x55 0xAA 0x11 0x01 0x08 0xCC 0xE5

Description:

Frame header --------- 0x55

Frame header --------- 0xAA

Device address ----- 0x11

Data length ----- 0x01

Command --------- 0x08

Operation status ----- 0xCC (0xCC - operation completed 0xEE - operation failed)

Checksum ------- 0xE5

Baud rate Selection List:

1200bps 2400bps 4800bps 9600bps 14400bps 19200bps 28800bps 38400bps 57600bps 115200bps 128000bps 256000bps
0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B

For example, when the device address is default 0x11, the baud rate setting command is as follows:

55 AA 11 01 08 00 19 //Set the baud rate 1200bps

55 AA 11 01 08 01 1A //Set the baud rate 2400bps

55 AA 11 01 08 02 1B //Set the baud rate 4800bps

55 AA 11 01 08 03 1C //Set the baud rate 9600bps

55 AA 11 01 08 04 1D //Set the baud rate 14400bps

55 AA 11 01 08 05 1E //Set the baud rate 19200bps

55 AA 11 01 08 06 1F //Set the baud rate 28800bps

55 AA 11 01 08 07 20 //Set the baud rate 38400bps

55 AA 11 01 08 08 21 //Set the baud rate 57600bps

55 AA 11 01 08 09 22 //Set the baud rate 115200bps

55 AA 11 01 08 0A 23 //Set the baud rate 128000bps

55 AA 11 01 08 0B 24 //Set the baud rate 256000bps