Complete Development Guide for MS72SF1 Millimeter-Wave Radar Module

The MS72SF1 is a millimeter-wave radar sensor module designed for people detection and smart control applications. This guide provides an overview of the hardware, setup process, configuration commands, data protocol, firmware upgrade procedure, and troubleshooting tips to help developers quickly integrate and deploy the MS72SF1 module.

Hardware Overview

The radar module integrates RF components for sensing.

1. Power Consumption:

lRF enabled: ~530 mA

lRF disabled: ~80 mA

lAverage current (100 ms frame period): ~110 mA

2. Power Input: Requires a stable 3.3 V supply with at least 1 A current capability.

3. Pins:

l3.3V – Power supply

lGND – Ground

lRX/TX – UART communication

lNRST – Reset pin (active low, normally floating)

Getting Started

Pre-Test Preparation

Step 1: Connect the module to a PC via a UART-to-USB adapter. The wiring is shown in the table below.

Configure the serial communication tool by selecting the corresponding port detected by the computer, and set up the link as follows:

lBaud rate: 115200

lData bits: 8 bits

lStop bits: 1 stop bit

lParity: None

lCH340 chip driver download: CH341SER.EXE

Step 2: Open the serial terminal software

① Select the port number

② Set the baud rate to 115200

③ Click Open Port

④ Select HEX Mode

⑤ Choose the desired language

Step 3: When the module is used in a new environment for the first time, it must first enter learning mode to acquire environmental information.

Note: During the learning process, ensure that there are no people within the radar's detection range. Frequent movement of personnel may cause the learning results to become invalid!

Data format:

The first two bytes 55 AA are the header

The third byte indicates the data length

The fourth byte indicates the data type

The fifth byte indicates the data result

The sixth byte is the XOR checksum

Step 4: After powering on, send AT+RESTORE\n to restore the module's configuration, then send AT+STUDY\n to enter learning mode.

The results will be output approximately 10 seconds after AT+STUDY is sent successfully.

1. When the module outputs 55 AA 06 00 B1 B7, it indicates that the detected scene differs from the interference positions stored in flash. Learning has successfully started. After 10 minutes, AT+RESTORE\n can be sent again to save the data to flash and formally start usage.

2. When the module outputs 55 AA 06 00 A1 A7, it indicates that the detected scene matches the interference positions stored in flash. The new positions have already been recorded to flash, and no further learning is required.

Step 5: After the module outputs 55 AA 06 00 B1 B7, wait for 10 minutes, then resend AT+RESTORE\n to restore the module. At this point, the environmental information has been saved to flash.

Configuration Parameters

The MS72SF1 supports a range of AT commands for configuration:

Height Configuration

Step 1: After sending AT+RESTORE\n, the module restores its default configuration. Previously learned information has already been saved to flash, and the learned data in flash will not be reset

Default Radial Distance: AT+RANGE=300\n        3m

Default Installation Height: AT+HEIGHT=270\n        2.7m

Default Detection Height: AT+HEIGHTD=270\n      2.7m

Threshold Setting

Default Threshold Value:   

AT+XNegaD=-300\n   Set X-Negative Boundary

AT+XPosiD=300\n    Set X-Positive Boundary

AT+YNegaD=-300\n   Set Y-Negative Boundary

AT+YPosiD=300\n    Set Y-Positive Boundary

The shaded area indicates the valid region

During normal operation, range parameters should be set according to the actual indoor space. The principle is to avoid scanning large objects such as walls or tables, which may interfere with the module. When configuring via the serial tool, HEX mode can be exited first.

Step 2: Send the range setting commands in sequence and outline the room area.

A successful configuration will return AT+OK=XXX, while a failed configuration returns Save Para Fail. In case of failure, the command should be resent.

Step3: After setting the range parameters, the module is ready for use. Launch the graphical PC software Radar_DemoCeilMountEN.exe.

①Select the port number and set the baud rate to 115200

②Open the serial port

③Select Mode

④Click Start

⑤Current Frame Number

⑥Current Number of People

Parameters such as height and elevation angle do not need to be set.

Data Output Protocol Format

Example

Firmware Update

Step 1: Connect the module to a PC via a UART-to-USB adapter. The wiring is shown in the table below.

Configure the serial communication tool by selecting the corresponding port detected by the computer, and set up the link as follows:

lBaud rate: 115200

lData bits: 8

lStop bits: 1

lParity: None

Step 2: Open Serial port upgrade tool.exe

①Search for Serial Ports

②Select Port

③Set the baud rate to 115200

④Open the por

⑤Select the firmware to be flashed

⑥Start Upgrade

Wait for the progress bar to complete. Once finished, the firmware update is complete. Successful flashing is shown as follows.

Watch the full tutorial video: https://youtu.be/plFVAd2RtYg

Troubleshooting (FAQ)

Q1: Module unresponsive after power-on?
A: Insufficient supply current. Use a stable 3.3 V, ≥1 A power source.

Q2：In a “people present” environment, the radar may occasionally fail to detect a person, or in a “no people” environment, it may falsely report a person. What could be the possible causes?

A：

Condiction 1: The radar scans a large area, detecting reflections from walls, doorways, or movement on the other side of wooden partition walls.

Adjustment: First complete the learning mode, then set the range according to the scene.

Condiction 2: The radar is positioned directly above running air conditioners or fans.

Adjustment: Reposition the radar so it does not face air conditioners or fans directly.

Condiction 3: Objects sway due to airflow from air conditioners.

Adjustment: Cotton or non-metallic items will not cause false detections. Metallic objects should be secured.

Condiction 4: The radar is not secured, and vibrations cause false detections.

Adjustment: Ensure the radar mount is stable and avoid any shaking or vibrations.

Condiction 5: Occasional movement of pets, birds, or other small moving objects.

Adjustment: The radar is highly sensitive to micro-movements, so this type of interference cannot be eliminated.

Condiction 6: Power interference occasionally causes false detections.

Adjustment: Ensure a stable power supply and minimize voltage ripple.

Q3: Why does the module require learning and calibration?
A: Study stores data of the new environment into flash memory as a reference baseline for operation, helping the module better determine the validity of detected targets. Calibration only needs to be performed during the first use; as long as the position remains unchanged, recalibration is not required. Data after calibration will not be erased by the AT+RESTORE\n command.

Q4: What do TLV, Q, and V mean?

lTLV – TLV serves as a separator between different types of data. 01 00 00 00 is followed by point cloud data, while 02 00 00 00 is followed by people count data.

lQ – A reserved bit (Reserved Bits, abbreviated as RSV) and is always 0.

lV – Velocity

Conclusion

The MS72SF1 millimeter-wave radar sensor module provides a powerful solution for people detection and smart environments. With proper setup, calibration, and parameter tuning, developers can quickly deploy it in applications such as occupancy sensing, smart lighting, security, and building automation.