When selecting sensors, it's important to avoid spending too much time setting up the evaluation environment and instead move quickly to actual device verification and specification confirmation.
Data acquired with Acconeer AB's (hereinafter referred to as Acconeer) 60 GHz millimeter-wave sensor IC "A121" can be viewed on a GUI using the dedicated evaluation tool "Exploration Tool" as information such as distance, phase, and velocity.
This article explains the process of launching the Exploration Tool and starting measurements in a Windows 11 environment using the XE125 evaluation board equipped with the Acconeer A121.
For engineers who want to "first verify distance and motion detection with actual equipment" or "quickly set up an initial evaluation environment for millimeter-wave sensors," this guide provides a step-by-step explanation, including screenshots, of the necessary software, drivers, programming to the evaluation board, and starting measurements with Sparse IQ.
Main functions that can be checked on the A121 evaluation board
Acconeer's Exploration Tool allows you to select an application suited to your needs and verify the operation of the A121. Figure 1 shows typical evaluation items that can be checked on the A121 evaluation board and examples of their application. First, identify the item closest to your evaluation objective from Figure 1, and then build the evaluation environment according to the procedure in this article.
For specific application examples and usage scenarios using the A121, please refer to our Acconeer company introduction page.
Figure 1: Evaluation items and application examples that can be checked on the A121 evaluation board.
The PCR method and the basic principles of the A121 are explained in detail in the related technical column, "Sensor Selection Without Failure - What is Acconeer's PCR Method?". This article focuses on the specific steps to begin the initial evaluation of the A121 using the evaluation board.
Overall flow of the A121 initial evaluation
The initial evaluation using the A121 evaluation board proceeds as shown in Figure 2. After preparing the necessary equipment and software for the evaluation, the PC environment is set up and the software is written to the evaluation board. Then, connect to the Exploration Tool and operate in the following order: select the application, set the parameters, and start the measurement. This article explains this series of steps with screenshots.
In actual product development, initial evaluations are conducted to confirm detection distance, responsiveness, and object detection stability. After determining compliance with the required specifications, the process moves on to parameter optimization and algorithm development.
Figure 2 Initial evaluation flow using the A121 evaluation board
Hardware and software required for evaluating the A121
To evaluate Acconeer's A121 sensor, you will need the following hardware and software:
Figure 3: Example of an evaluation environment using XE125
Table 1 Hardware required for A121 evaluation
| Item number | name | Details |
|---|---|---|
| ① | A121 Evaluation Board |
-XE121/XC120/XS121 -XE125 |
| ② | Communication POWER CABLES | USB CABLES (Type-C) |
| ③ | Evaluation PC | - PCs with Windows 11 - A PC with Ubuntu 24.04 installed |
The differences between XE121 and XE125 are explained in detail in the related technical column, "Sensor Selection Without Failure - What is Acconeer's PCR Method?".
This article will focus on the XE125, one of the most frequently used A121 evaluation boards. The evaluation PC used will be based on a Windows 11 environment, commonly found in corporate settings.
If you are considering checking the specifications or purchasing the A121 evaluation board, XM125 module, or related products, please also refer to the Acconeer introduction page. If you are unsure of your evaluation purpose or required configuration, we can also advise you on selecting an evaluation environment suitable for your application.
Table 2 Software required for A121 evaluation
| Item number | name | Details |
|---|---|---|
| 1 | Evaluation tool | Exploration Tool |
| 2 | USB driver | COM port driver for Windows |
| 3 | Python | Software for launching the Exploration Tool Python 3.9/3.10/3.11/3.12/3.13 recommended. |
| 4 | Exploration server A121 | Software for the A121 Evaluation Board |
The following chapters will explain the installation procedures for each software program in order.
Preparing the Python execution environment
Since the Exploration Tool runs on Python, you will need to prepare a Python execution environment beforehand.
This chapter explains the steps to set up the Python environment necessary to launch the Exploration Tool.
- 1.
Access to the official Python website and download the installer.
- 2.
Check the Python version recommended by the Exploration Tool listed in Table 2 and select a version within the supported range.
As an example, we will use Python 3.13 here. The screen display may differ depending on the version. - 3.
If you are using Windows 11, select and download "Windows installer (64-bit)".
- 4.
Run the downloaded installer.
- 5.
The Python setup screen will appear. Since the Exploration Tool is launched using the Python command from the command prompt, check "Add python.exe to PATH" and then select "Install Now".
Figure 4 PATH settings during Python installation
- 6.
After the installation is complete, select "Close" to exit the installer.
- 7.
Open a command prompt and run "python --version" to verify that Python is installed correctly.
If the version information is not displayed, restart your computer and check again. If the problem persists, check your PATH settings.
Example: python --version
Python 3.13.14
Figure 5: Checking the Python version
Installation instructions for the Exploration Tool
Once your Python environment is ready, install the Exploration Tool.
This procedure can be used not only when performing a new installation of the Exploration Tool, but also when updating it.
- 1.
Launch the command prompt.
- 2.
The following command will update pip, the package management tool included with Python, to the latest version.
If you already have the latest version, a message will be displayed indicating that no update is necessary.
python -m pip install --upgrade pip
Figure 6: Results of executing Python pip update
- 3.
Install the Exploration Tool using the following command:
python -m pip install --upgrade acconeer-exptool[app]
Once the installation is complete, the message "Successfully installed..." will appear on the screen.
Figure 7: Exploration Tool installation results
Note: The "python -m pip install" command connects to PyPI (Python Package Index), where Python packages are distributed, and automatically downloads the necessary files. Therefore, an internet connection is required during installation.
However, on corporate networks, you may be unable to connect to PyPI due to proxy or security settings. If you are unable to connect, a message indicating a retry or connection failure will be displayed on the screen, and you will not be able to download the necessary files. If you are unable to connect on your company network, check your proxy settings or try again from a network environment where connection is possible.
Figure 8: Example of a Python package retrieval error in a restricted network environment.
USB driver installation and port verification
The A121 uses SPI as its host interface, while the XM125 module uses UART/I2C. The evaluation board is connected via a USB conversion circuit so that it can be controlled from a PC. A USB driver must be installed for the PC to recognize and control the evaluation board.
First, connect the XE121/XC120 or XE125 evaluation board to your computer using a USB CABLES.
Next, open Device Manager and check if the evaluation board is recognized correctly.
If the USB driver is not installed, two COM ports will appear under "Other devices".
Figure 9 Device Manager when XE125 is connected.
(Before driver installation)
XE121/XC120 USB Driver
The XE121/XC120 is usually automatically recognized by Windows 11. When you connect the XE121/XC120 to a Windows 11 environment via USB, it will appear in Device Manager as follows:
Figure 10 Device Manager when XE121/XC120 is connected
However, the Exploration Tool may not function correctly depending on your computer or Windows environment. In that case, you will need to check the official Acconeer procedure and review the status of WinUSB/WCID.
- 1.
Download version 2.7 or later of the Zadig tool from the official website.
- 2.
Connect the XE121/XC120 to your computer via USB.
- 3.
Run the downloaded "zadig-xxexe".
For example, in the case of version 2.8, run "zadig-2.8.exe". - 4.
Select "List All Devices" from "Options".
- 5.
Select "XC120 Exploration Server" from the dropdown list.
Review the WinUSB application details and select either "Replace Driver" or "Downgrade WCID Driver".
Figure 11 WinUSB driver application/WCID driver change screen
- 6.
After the installation is complete, select "Close".
XE125 USB Driver
- 1.
Download the USB driver for the XE125 from Silicon Labs' "CP210x Windows Drivers" page.
- 2.
Run the downloaded USB driver installer.
Example: 2-1. Run "CP210xVCPInstaller_x64.exe". 2-2. When the USB driver installation screen appears, select "Next (N) >".
2-3. When the license agreement is displayed, review its contents. If there are no problems, check "I accept (A)" and select "Next (N) >". After selection, the USB driver installation will begin.
2-4. When the installation completion notification appears, select "Finish". - 3.
After installation, verify that "Enhanced COM Port" and "Standard COM Port" are displayed under "Ports (COM & LPT)" in Device Manager. (The COM port number will vary depending on your computer environment.)
Figure 12 Device Manager when XE125 is connected.
(After USB driver installation)
Launching the Exploration Tool and writing the software to the evaluation board.
At this point, the basic settings on the PC side are complete. From here, we will explain how to start the Exploration Tool, download the evaluation software, and write it to the evaluation board.
Launching the Exploration Tool
- 1.
Open the command prompt and run the following command to launch the Exploration Tool.
python -m acconeer.exptool.app
If you want to avoid the hassle of typing commands every time, it's convenient to create a .bat file for launching the application. - 2.
When the sensor IC selection screen appears, select "A121".
Figure 13: Exploration Tool startup screen
- 3.
The main screen of the Exploration Tool for A121 will be displayed.
Figure 14 Exploration Tool Main Screen
Software download
- 1.
Access Acconeer's Developer website.
- 2.
Select the login icon in the upper right corner of the Acconeer website and enter your email address and password to log in. If you do not have an account, register by entering your name, email address, company name, and password under "Register".
Figure 15: Login screen for the Acconeer website.
- 3.
After logging in, select "A121".
Figure 16: Acconeer website A121 selection screen
- 4.
Once the A121 Products page opens, select the item corresponding to the evaluation board you will be using. Since the content for the XE121 and XM125/XE125 is largely the same, the following explanation will use the XM125/XE125 as an example. Note that the XE125 is an evaluation board equipped with the XM125.
Figure 17: Acconeer website, A121 Products page
- 5.
From the "Software" section on the XM125/XE125 page, select "DOWNLOAD >" for "ACCONEER XM125 EXPLORATION SERVER A121".
Figure 18: Acconeer website XM125/XE125 software selection screen
- 6.
Before downloading, the software license agreement will be displayed. Please review the contents, check the checkbox if you agree, and select "Download →".
Figure 19: Acconeer website, license agreement and download screen.
Writing software to the evaluation board
- 1.
Select "Flash" from the menu on the left side of the Exploration Tool.
Figure 20 Software writing mode selection
- 2.
Select the evaluation board to program from "Module". If you are using the XE125, select the installed module, "XM125".
If you are using the XE121, select the corresponding "XC120". - 3.
Select the connected XM125/XE125 device. Check "Show all devices" and select the COM port number you confirmed in Device Manager. After selecting the COM port number, select "Next". Note that two types of COM ports will be displayed for the XE125, but either can be selected for software programming.
Figure 21 Software writing port selection
- 4.
Select how to obtain the software to write to the drive. If you want to write the file you downloaded earlier, select "Local file" and then select "Next".
Figure 22 Software Writing Method Selection
- 5.
Select the downloaded "acc_exploration_server_a121.bin" and then select "Next".
Figure 23 Software Writing File Selection
- 6.
Select the "Flash" button.
Figure 24 Software writing starts
- 7.
Switch the evaluation board into software programming mode (Bootloader mode). Operate the buttons on the back of the evaluation board according to the following procedure.
- 1.)
Press and hold the DFU button.
- 2.)
Press and hold the RST button or the RESET button.
- 3.)
Continue pressing and holding for more than one second.
- 4.)
Release the RST button or the RESET button.
- 5.)
Finally, release the DFU button.
-
Figure 25 Bootloader mode transition procedure
-
Figure 26 DFU/RST button on the back of the XE125
- 1.)
- 8.
Once you have set the evaluation board to Bootloader mode, select the "Got it! The board is in bootloader mode" button in Figure 25. The software will then begin writing. "Flashing..." will be displayed during the writing process.
Figure 27 Software Writing Screen
- 9.
Once the writing process is complete, "All done" will be displayed, so select "Finish".
Afterward, either press the "RST" button on the evaluation board or unplug and replug the USB CABLES to reset the evaluation board.
Figure 28 Software writing complete
Start measuring A121 with the Exploration Tool.
At this point, the setup of the evaluation board and Exploration Tool is complete. From here, we will explain the basic operations for performing measurements using the Exploration Tool.
The basic operation process consists of the following four steps:
- 1.)
Connecting the Exploration Tool to the Evaluation Board
- 2.)
Application Selection
- 3.)
Setting parameters
- 4.)
Measurement started
Connecting the Exploration Tool to the Evaluation Board
When using the Exploration Tool, you must first configure the connection to the evaluation board. Connect to the evaluation board using the following steps:
- 1.
Select "Stream" from the menu on the left.
- 2.
In the interface selection section, select the connection method that corresponds to the evaluation board you are using.
For XE125: Serial
For XE121/XC120: USB - 3.
Select the port to connect to using the Exploration Tool.
For XE125: Select the COM port number displayed as "Enhanced COM port" in Device Manager.
Figure 29 Evaluation board connection button (when XE125 is connected)
For XE121/XC120: Select XC120.
Figure 30 Evaluation board connection button (when connecting XE121/XC120)
- 4.
Select the "Connect" button to connect.
Application Selection
The Exploration Tool includes applications such as Sparse IQ, which allows you to check basic operations like distance and phase changes, as well as distance detection and presence detection, enabling you to evaluate its operation under conditions close to real-world use.
- 1.
Select an application from the menu on the left.
As an example, let's select "Sparse IQ". - 2.
Verify that the display at the top center of the screen switches to the selected application.
Figure 31 Application Selection
Setting parameters
Depending on the selected application, parameters are set to match the evaluation conditions. In the A121, parameters such as Start point, Number of points, Step length, HWAAS, Profile, and PRF are set to adjust the balance between measurement distance, distance direction discrimination, SNR, measurement time, and power consumption. Parameters can be set by direct numerical input, modification using spin buttons, or selection from a drop-down list.
For key parameters, please refer to "Key Parameters to Check in the A121 Initial Evaluation" below.
Each application comes with "Preset Configurations," which are recommended settings. For initial evaluation, we recommend using a Preset Configuration, and then adjusting the main parameters to suit your specific needs after confirming its operation.
If you enter a value outside the specified range, an error message will be displayed, allowing you to adjust it while checking the screen.
Measurement started
At this point, the initial setup of the A121 is complete. We will now start taking measurements using the Exploration Tool.
- 1.
Select "Start measurement" to begin the measurement.
Figure 32 Measurement Start Button
- 2.
The measurement results are displayed in the central display area of the Exploration Tool. Sparse IQ allows you to visualize distance, phase, and velocity information in real time.
Distance display: Used to determine the distance from the peak position of the reflectance intensity to the target object.
Phase display: Used to observe minute movements based on the time change of phase.
Speed display: Used to analyze Doppler information for each distance and determine the speed of the object.
Figure 33 Exploration Tool measurement screen (Sparse IQ)
- 3.
Select "Stop" to end the measurement.
Figure 34 Measurement End Button
Key point: Saving measurement data can be used to review evaluation results and investigate problems.
The Exploration Tool temporarily stores measurement data, allowing you to save and load it as needed.
- Checking "Enable recording" will allow you to retain the current measurement data until you start the next measurement.
- The saved measurement data can be saved in .h5 format using "Save to file".
- Saved data can be loaded from "Load from file" and played back or reviewed later.
Figure 35 Measurement Data Management Button
If unexpected behavior occurs during evaluation, please share a diagram of the evaluation environment, photos, and saved .h5 files so we can assist you in investigating the cause based on the acquired data.
Key parameters to check in the initial evaluation of A121
You can set parameters such as the output pulse length, measurement start distance, and number of measurement points according to your evaluation objectives. The following are the main parameters that should be checked in the initial evaluation of Sparse IQ.
Start point: Measurement start distance (2.5 mm x set value)
Set the distance at which measurement and display will begin in the Exploration Tool.
The A121 is capable of short-range measurements. However, due to "direct leakage," where the signal from the transmitting ANTENNAS directly bends back to the receiving ANTENNAS, reflections may appear to occur at close range even when there is no object being measured. When evaluating short-range measurements, settings and corrections that take the effects of direct leakage into account are necessary.
In the Exploration Tool, set a Start point that is less susceptible to direct leakage, referring to the table below.
Table 3 Direct leakage impact distance for each profile setting
| Profile | Direct leakage[m] |
|---|---|
| Profile 1 | ～0.06 m |
| Profile 2 | ～0.10 m |
| Profile 3 | ～0.18 m |
| Profile 4 | ～0.36 m |
| Profile 5 | ～0.60 m |
Number of points: Number of measurement points
The "Number of points" parameter sets the number of measurement points to acquire at intervals of the "Step length" from the "Start point." In Sparse IQ, reflection intensity and phase information are acquired at each measurement point and used for analyzing the distance to the object and minute movements. Increasing the number of measurement points allows for the acquisition of information over a wider distance range, but it also increases the amount of data acquired, thus increasing power consumption and processing time. Please adjust the number of points according to your application, considering the balance between the distance range to be evaluated, the update cycle, and power consumption.
Step length: Distance between measurement points (2.5 mm × set value)
Reducing the step length narrows the interval between measurement points, allowing you to improve the resolution in the distance direction. However, widening the measurement range increases the number of measurement points, which in turn increases power consumption and processing time.
Please note that there are limitations on the values that can be set for Step length in the Exploration Tool. Adjust the available values while checking the error messages displayed on the screen.
Measurement range: From start to end of measurement
Measurement start distance: Start point × 2.5 mm
Measurement end distance: {Start point + (Number of points - 1) × Step length} × 2.5 mm
For example, if Start point = 80, Number of points = 40, and Step length = 8, the starting distance for measurement is 0.20 m, and the distance between measurement points is 0.02 m, so the measurement range is 0.20 m to 0.98 m.
HWAAS (Hardware Accelerated Average Samples): Hardware averaging to improve SNR.
Increasing the number of HWAAS (Hyperweighted Wiring Alignment) cycles improves the signal-to-noise ratio (SNR) by averaging random noise. This makes it easier to detect distant objects and minute movements. On the other hand, increasing the number of averaging cycles increases the measurement time, thus reducing the frequency of updating the measurement results.
Profile: Pulse duration and waveform shape
A larger Profile value results in a longer pulse train output. The main characteristics of longer pulse lengths are as follows:
- Because the released energy increases, the signal-to-noise ratio (SNR) tends to improve.
- Long-distance measurements will be advantageous.
- Under certain conditions, this can lead to a reduction in measurement time.
- Because the distance resolution decreases, it becomes difficult to separate multiple objects that are close together.
- Because the area affected by direct leakage is widened, short-range measurements become difficult. Therefore, you need to set the start point further away, referring to Table 3.
Figure 36 shows the difference in detection results depending on the profile settings. Profile 2 is able to detect and separate the three objects.
On the other hand, Profile 3 fails to separate two objects at close range and detects them as a single object. However, due to the longer pulse length, the amplitude of the reflected signal becomes larger.
Figure 36 Detection results by profile (for reference)
Receiver gain: Gain setting for receiving reflected waves.
Receiver gain sets the amount of amplification of the received signal. Increasing the value makes it easier to observe weak reflections, but care must be taken to avoid noise amplification and saturation due to strong reflections.
PRF (Pulse Repetition Frequency): Pulse repetition frequency
PRF presents a trade-off between measurement time, power efficiency, and MMD/MUR. The required measurement range and the possibility of reflections due to objects outside the range are checked, and a high PRF is selected within the range that satisfies the conditions.
MMD (Maximum Measurable Distance): Limitation of the maximum measurable distance.
The maximum measurable distance is determined by the limitations of the sensor settings.
The endpoint of the measurement range is determined by "Start point + (Number of points - 1) × Step length," but it must be set so that it does not exceed the MMD. Reducing the PRF will lengthen the MMD.
MUR (Maximum Unambiguous Range): Maximum detectable distance
MUR (Meaningless Urgent Range) is an index that represents the maximum distance at which the reflected wave can be uniquely measured without being confused with the next transmitted pulse. Objects farther away than the MUR may be detected as being at an incorrect distance due to reflection. For example, if the MUR is 11.5 m, an object at 13.5 m may be detected as an object at approximately 2 m.
Table 4 List of MMD/MUR for each PRF setting
| PRF settings | MMD | MUR |
|---|---|---|
| 19.5 MHz[※] | 3.1 m | 7.7 m |
| 15.6 MHz | 5.1 m | 9.6 m |
| 13.0 MHz | 7.0 m | 11.5 m |
| 8.7 MHz | 12.7 m | 17.3 m |
| 6.5 MHz | 18.5 m | 23.1 m |
| 5.2 MHz | 24.3 m | 28.8 m |
* PRF = 19.5 MHz is only available for Profile 1.
Summary
This article explains everything from setting up an evaluation environment for Acconeer's A121/XE125, to configuring connections using the Exploration Tool, starting measurements, and checking key parameters.
Using the Exploration Tool, you can set various parameters on the GUI and visually verify the operation of the A121 based on distance, phase, and velocity. Since you can check the detection distance, responsiveness, and object detection stability at the initial evaluation stage, you can efficiently proceed with the initial evaluation of the millimeter-wave sensor.
If you encounter difficulties setting up your evaluation environment, or if you have any questions regarding parameter settings or evaluation methods tailored to your specific application, please feel free Inquiry.
Next time, we'll introduce examples of how to use each application included in the Exploration Tool.
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