ST MEMS Sensor Evaluation Environment Building Guide ②: Explanation of Evaluation Environment Building Procedures | NEXTY Electronics, an Electronic Components and Semiconductor Trading Company

The initial evaluation of the device is completed quickly, and then we move on to actual evaluation and product development.
The MEMS sensor evaluation tool from STMicroelectronics (hereafter referred to as ST) has an intuitive board structure and easy-to-understand GUI, making it easy for even first-time users to check the operation of sensors. This article will introduce ST's MEMS sensor products and provide an easy-to-understand explanation of the setup procedure for the evaluation tool in a two-part series, helping you to start evaluating devices right away.

Review of ST's MEMS evaluation tools

In the first article, we introduced MEMS products and provided an overview of evaluation boards and evaluation software.

The first article is here: "ST MEMS Sensor Evaluation Environment Construction Guide ① Explanation of the Features of 6-Axis Sensors and Evaluation Tools"

In this article, we will explain the specific connection procedures, settings, and troubleshooting methods using these devices.
Before actually running it, we will clarify the configuration of the ST evaluation board we will be using and the role of MEMS Studio.

Evaluation board

The motherboard STEVAL-MKI109D, which is equipped with an STM32H563, is used with an adapter board equipped with each sensor product.
All adapter boards have the same board shape and can be attached to and detached from the DIL24 SOCKETS on the motherboard.
In this article, we will use the STEVAL-MKI251A, which is equipped with the LSM6DSV320X, an accelerometer and gyroscope integrated into one package, as the adapter board.

Evaluation software

We use the free software MEMS Studio released by ST.
MEMS Studio allows you to use a variety of functions necessary for evaluating MEMS sensors, such as setting the registers of the MEMS sensor on the adapter board, reading measurement data, plotting it as a graph, and saving it as a log.
Additionally, it also implements additional features such as algorithm generation for edge processing, including a Finite State Machine (FSM) and a Machine Learning Core (MLC).

We will also introduce the STM32CubeProgrammer, which can be useful for troubleshooting various issues related to the evaluation board.
STM32CubeProgrammer is a tool that can rewrite the built-in flash memory of ST's STM32 series microcontroller products.
Although we will not implement it in this article, there is also a security-conscious writing mode that has been gaining attention in recent years.

Advance preparation

Download and install the evaluation software (MEMS Studio, STM32CubeProgrammer)

① MEMS Studio

It can be downloaded from the ST product page below.

[MEMS Studio, evaluation software for ST's MEMS sensors]

In the "Get Software" section of the web page, you can choose from three operating systems: Windows, Mac, and Linux.
In this article, we will download the software for Windows.

When you click the "Get Latest Version" button, a license agreement screen will pop up.

Check the contents and if there are no problems, click "Accept."
A pop-up will then appear requesting you to log in to your ST account.
To use MEMS Studio, you will need a MyST account, so if you don't have one, we recommend you create one here.

After logging in, the pop-up may close temporarily.
In this case, click the "Download latest version" button again in the "Get software" section and the download will begin in your browser.
For Windows, a file called "MEMS-Studio-Win.zip" will be downloaded.
Extract the downloaded zip file and run the file "mems-studio-2.2.0.exe" to install the software.

② STM32CubeProgrammer

Next, download the STM32CubeProgrammer.
You can download it from the URL below using the same procedure as for MEMS Studio.

[ST's STM32CubeProgrammer, a programming tool for STM32 microcontrollers]

STM32CubeProgrammer is available in 32-bit and 64-bit versions for Windows.
There are also preparations for Mac, Linux, and Mac (Arm).

For the Windows 64-bit version, the file "stm32cubeprg-win64-v2-21-0.zip" will be downloaded.

*The "v2-21-0" part of the file name may be written differently depending on the downloaded version.
When you extract the downloaded zip file, you will find "SetupSTM32CubeProgrammer_win64.exe" stored there. Run it to install the software.

MEMS Studio Initial Setup

First, launch MEMS Studio.
The evaluation board does not need to be connected to a PC.

Click on "Settings" in the menu (left side of the window) and go to "myST Login".

Enter the account information you created when downloading the software and click the "Login" button to complete the sign-in process.
Once you have successfully signed in, you will remain signed in the next time you start the app.

Next, connect the STM32CubeProgrammer.
Similarly, go to "Settings" and then "External Tools."

There are various tool names listed, but this time we will register them in "STM32CubeProgrammer path:".
Click "Browse" and navigate to the STM32CubeProgrammer installation folder.
If you installed STM32CubeProgrammer in the default state, please refer to the following directory.
<C:\Program Files\STMicroelectronics\STM32Cube\STM32CubeProgrammer>

Furthermore, if you go to the "bin" folder in the installation folder, you will find "STM32_Programmer_CLI.exe" stored there.
Select this and click the "Open" button, and the notation will be added to the "STM32CubeProgrammer path:" field in MEMS Studio.
The "CLI" in "STM32_Programmer_CLI.exe" stands for Command Line Interface.

This completes the setup of MEMS Studio.

Connecting the evaluation board

I would like to connect the evaluation board to my PC right away,
Before connecting, make sure the adapter board is facing the correct direction.
The correct installation orientation is when the ST logos printed on the motherboard and adapter board match.
There is also a logo on the top side of the microcontroller on the motherboard, but be careful to match it with the logo on the board.

Also, make sure the adapter board is securely attached to the motherboard.
This prevents poor connection due to poor contact.
It's a little hard, so be careful not to injure yourself.

Once assembled, connect the evaluation board to your PC using a USB Type-C CABLES.
The evaluation board is powered by the PC.
At this time, the green LED (D5) next to the USB Type-C CONNECTORS will light up.
The green LED (D6) near the corner of the board will also light up.
If the green LED (D6) does not light up, please check troubleshooting step ③ first.

Return to MEMS Studio and click “Connect” in the menu.
If the evaluation board has been detected without any problems, the COM port number should be displayed in the "Communication port:" field.
If the "Communication port:" field displays "No board detected," please refer to Troubleshooting ① below.
Also, if a pop-up appears at this stage requesting that you update the firmware of the evaluation board, please check Troubleshooting ②.

Once MEMS Studio has detected the motherboard, you can proceed with the connection.
First, go to the "Connect" menu in MEMS Studio and check that the COM port to which the motherboard is connected is displayed in the "Communication port:" field.
Next, click "Connect" and the button will change to "Disconnect," and an area for selecting the adapter board will appear in the lower center of the window.

You can search in the "Direct device search:" field in the middle.
This time we will use the STEVAL-MKI251A equipped with the LSM6DSV320X, so you can easily find it by entering words such as "320" or "251".

Select the adapter board you want to use and click the "Select" button.

Once the PC, motherboard, and adapter board are connected, you will automatically be taken to the "Sensor Evaluation" menu on the left side of the MEMS Studio window.

MEMS sensor initial setup

If you can access the “Sensor Evaluation” menu on the left side of the MEMS Studio window, you are almost there until the sensor is operational.

"Quick Setup" is available at the top of the "Sensor Evaluation" submenu.
Detailed settings are possible from the "Register Map" below, but here we will check the operation using a simple setting method.

Click the "Easy Configuration" button at the top of the window.
This will load the device with the typical settings that were provided.
The settings you have made are displayed in the center of the window.
Users can also change the settings from each drop-down menu to their liking, and the settings will be immediately applied to the device.
When the Output Data Rate (ODR) is changed from "Power-Down", the device will start measuring.

Data acquisition and log storage

The device starts measurement when the ODR is set, so the data is read out using MEMS Studio.

First, click the pink play button in the top left corner of the window.
MEMS Studio will begin reading data from the device (the button will change to a Stop button).

The read data will be displayed in the display format selected from the "Sensor Evaluation" submenu.
As typical examples, we will introduce two display modes.

・Line Charts
The transition of acceleration and gyro measurement data can be visually confirmed in graphs.

・Data Monitor
In addition to acceleration and gyro, you can check selected data such as values obtained from the built-in TEMPERATURE SENSORS all on one screen.

Next, we will introduce how to save the read data as a log.
Select "Save to File" from the "Sensor Evaluation" submenu.

Configure the log file to be saved.
Use the "Browse" button to the right of the "Log file:" field to specify the name and location of the log file.
If "Set timeout:" is disabled, logging will continue until the user clicks the "Stop" button.
If you enable "Set timeout:", log acquisition will stop after the time set in "Timeout value:" has elapsed.
Even if "Set timeout:" is enabled, you can still stop it by clicking the "Stop" button.
In the "Data:" field, you can select the items to be saved in the log.

When you're ready, click the "Start" button.
When the time set in "Timeout value:" has elapsed or when you click the "Stop" button, logging will stop and the log will be saved to a file.

An example of the saved log is as follows:

Troubleshooting evaluation board connections

Here we will introduce three examples of troubleshooting that can be seen when connecting an evaluation board.

Troubleshooting ① Windows does not recognize the device

First, start the Windows Device Manager.
In the "Ports (COM & LPT)" column, check that "USB Serial Device" is added when you connect the evaluation board.

If "USB Serial Device" is not added, it is possible that the USB driver was not installed properly.
The driver installer is stored in the STM32CubeProgrammer installation folder.
Please run "dpinst_amd64.exe" stored in the following directory.
<C:\Program Files\STMicroelectronics\STM32Cube\STM32CubeProgrammer\Drivers\stsw-link009_v3>

Once completed, please check the operation of MEMS Studio again.
If a pop-up message appears instructing you to update the firmware on the evaluation board, follow the troubleshooting step ② below to update the firmware written in the microcontroller on the motherboard.

Troubleshooting ② Evaluation board firmware update

Click "Firmware Programming" from the menu on the left side of the window.

Click the "Firmware Directory" button to the right of the "File name:" field.
This will display the folder in the MEMS Studio installation folder that contains the firmware for the motherboard.

This time, we are using the STEVAL-MKI109D as the motherboard, so we will move to the folder with the corresponding name.
The folder contains the binary file "ProfiH5_MKI109D_V1.5.3.bin." Select it and click the "Open" button, and the path to the selected binary file will be entered in the "File name:" field.

Next, select the connection method to the motherboard.
Select "DFU" from the drop-down menu in the "Interface:" field.
"DFU" is an acronym for Device Firmware Update, and in this case it is a method of rewriting the microcontroller firmware via USB.

Next, change the operating mode of your motherboard to DFU mode.
There are three buttons on the motherboard.
They are gathered in the upper left corner of the motherboard as shown in the image below.
To enter DFU mode, use BT2 (BOOT) and BT3 (RESET).

With the PC and motherboard connected via USB CABLES, perform the following steps:
①Press and hold BT2
②Press and release BT3
③Release BT2

The green LED (D6) will then turn off.
At the same time, the detection results will be displayed in the "Device:" field in MEMS Studio.

Once your motherboard is detected, click the "Program" button and the firmware update will be performed.
At this time, the STM32CubeProgrammer that was linked earlier is running.

When "Success" appears in the bottom left corner of the pop-up programming window, click the "Close" button.
Then press BT3 on the motherboard to reboot into normal operation mode.

Troubleshooting 3: The evaluation board has stopped working

If a problem occurs with the firmware update introduced in Troubleshooting ②, and the device should be operating in normal operating mode, the green LED (D6) on the motherboard may remain off, and the COM port may not be recognized in MEMS Studio's "Connect" menu.
Updating the firmware again using MEMS Studio may solve the problem, but if that doesn't solve the problem, try the following method.

What will be done is to erase the firmware written in the microcontroller on the motherboard and rewrite it.

First, start the STM32CubeProgrammer.
Here we will use the installed version, not the CLI version linked to MEMS Studio.

Once STM32CubeProgrammer has launched, select "USB" from the light blue pull-down menu in the upper right corner of the window.

Next, put your motherboard into DFU mode.
Let me explain the steps again.

To enter DFU mode, use BT2 (BOOT) and BT3 (RESET).

With the PC and motherboard connected via USB CABLES, perform the following steps:
①Press and hold BT2
②Press and release BT3
③Release BT2

Return to STM32CubeProgrammer and click the refresh button to the right of "Port" to detect the motherboard that has entered DFU mode.

Once the motherboard is detected, click the light green "Connect" button.
The firmware written to the microcontroller on the motherboard will then be read and displayed in the central area of the window.

Perform the firmware erase operation.
Go to "Erasing & Programming" from the menu on the left side of the STM32CubeProgrammer window.

Click the "Full chip erase" button under "Erase flash memory" in the center of the window.

A pop-up will appear asking if you are sure you want to delete it, so click "OK".

If the deletion is successful, a pop-up will appear; click "OK".

If you return to "Memory & File editing" from the menu on the left side of the window, you will see that the firmware written to the microcontroller has been erased and all data has been set to 0xFF.

Next, rewrite the firmware.
Return to "Erasing & Programming" from the menu on the left side of the window.
Select the firmware to be written from "Browse" in the center left of the window.

Here, select the firmware binary for STEVAL-MKI109D, "ProfiH5_MKI109D_V1.5.3.bin".
In a standard installation of MEMS Studio, it is stored in the following directory:
<C:\Users\User name\AppData\Local\STMicroelectronics\MEMS Studio\firmware\mems-studio\steval-mki109d>
This is the same binary file you selected in Troubleshooting ②.

Enter "0x08000000" in "Start address".
Check "Verify programming" and click the "Start Programming" button.

If the writing is successful, the messages "File download complete" and "Download verified successfully" will pop up in succession.

Return to "Memory & File editing" from the menu on the left side of the window and click the "Read" button. The written firmware will be read from the microcontroller.

Once you have confirmed that the firmware has been written, click the yellow-green "Disconnect" button on the right side of the window to disconnect the STM32CubeProgrammer from the motherboard.

Press the BT3 (RESET) button on the motherboard to reset it and operate it in normal operating mode.
Return to MEMS Studio and check if the motherboard is detected.

Summary

This article explained the steps to set up an evaluation environment for ST's MEMS sensors and the basic usage methods. MEMS Studio also implements many other functions. The user manual UM3233 published on ST's website is also useful. It can be viewed at the following URL: