In this workshop, you can experience the following things with B-L475E-IOT01A Discovery board.
- Build IoT device firmware using Mbed Online Compiler
- Manage the IoT device on Pelion Device Management
- Update the IoT deivce's firmware by OTA (over-the-air)
Please use Chrome or Firefox. Edge and Internet Explorer may cause problen in this workshop process.
Do not open multiple windows of Pelion Device Management console or online compiler. It may cause an error.
In this workshop, we use terminal software for monitoring messages from the IoT device. Please install Teraterm (Windows), Coolterm (Windows/macOS/Linux), or other terminal software.
On Windows, you might need to install this device driver. Please download and install: https://www.st.com/content/st_com/en/products/development-tools/software-development-tools/stm32-software-development-tools/stm32-utilities/stsw-link009.html
In this workshop, we use Mbed online compiler. Please create an account before the workshop if you don't have one.
https://os.mbed.com/account/signup/
Please make sure that E-mail verification is done, otherwise you'll fail to get Free Trial in the next step.
In this workshop, we use Pelion Device Management. Please request free trial of Pelion Device Management from the following page. You need an Mbed account created above to apply your request.
https://console.mbed.com/cloud-registration
Input the required fields, then click the Submit button. You will be jumped to Pelion Device Management Portal. In the middle of the process, log in page appears. Click the Log in with Mbed.com button.
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Forwarded to the license agreement page, read it carefully and accept the license agreement.
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Once you finished the above process, you can close the Device Management Portal page.
Let's create a firmware image contains Pelion Device Management Client, which connects to Pelion Device Management. Then apply the firmware image to the B-L475E-IOT01A Discovery board and create an IoT device.
Adds B-L475E-IOT01A Discovery kit for IoT node to your Mbed account. Please add by either way below.
Log in Mbed.com and follow this:
- Connect your PC and your board with USB cable. The board is recognized as a USB storage.
- Open the
MBED.HTMfile with browser.
Open this page:
https://os.mbed.com/platforms/ST-Discovery-L475E-IOT01A/
Click the ** Add to your Mbed Compiler** button at the right side.
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When you click, the platform is added to your account and you'll see the message "Platform 'DISCO-L475VG-IOT01A' is now added to your account!".
Let's import the firmware project into your workspace in online compiler. Go to the page below. You need to log in Mbed web site. Click the yellow button Import into Compiler.
https://os.mbed.com/users/coisme/code/Pelion-DM-Workshop-Project/
Click the Import into Compiler button, you'll be moved to the online compiler. Then the confirmation dialog will appear. Click the Import button to import. Do NOT check Update all libraries to the latest revision check box.
Sets the Wi-Fi access point which IoT device connect to. Open the mbed_app.json file in the project root, then edit the items below in the target_overrides section.
"nsapi.default-wifi-security" : "WPA_WPA2",
"nsapi.default-wifi-ssid" : "\"SSID\"",
"nsapi.default-wifi-password" : "\"Password\""WEP, WPA, WPA2, or WPA_WPA2 can be set for nsapi.default-wifi-security. Set an appropriate one correspond to your access point. Set SSID of your access point to nsapi.default-wifi-ssid, and set your password to nsapi.default-wifi-password. Note that you need to add the escaped quotation mark \" at the head and tail of the string in quotation marks. Here's the example when SSID is ArmMbed and password is abc1234.
"nsapi.default-wifi-security" : "WPA_WPA2",
"nsapi.default-wifi-ssid" : "\"ArmMbed\"",
"nsapi.default-wifi-password" : "\"abc1234\""Let's create a file which contains certificates and other information, these are needed to connect to Pelion Device Management. Open the Pelion Device Management menu at the top of online compiler window and click the Manage Connect Certificates.
You'll see the dialog to select a certificate. You won't see any certificate at the first time. Click the Create button to create a new certificate.
Input name and click the OK button.
The certificate is created with the name you input. Select it and click the OK button.
Then you'll see the dialog box to confirm overwrite mbed_cloud_dev_credentials.c, click the OK button. In this step, developer certificates and other parameters are added into mbed_cloud_dev_credentials.c.
Create key pairs and certificates to verify download firmware when update is performed via network.
Open the Pelion Device Management menu at the top of online compiler window and click the Apply Update Certificate.
Confirmation dialog appears, click the Create button.
You'll see the dialog to confirm update_default_resources.c and update_certificate.pem will be overwritten. Click the Create button. These files will be created and overwritten if exist.
Then you'll see the dialog to download private key to sign update firmware, click the Download Private Key button and download the private key file. Do not share this key file with other people. Store it at secure place.. This key is used later.
Now we're ready to build the project. Click the Compile button at the top of online compiler window.
Once compile is finished, the firmware binary file (project name).bin will be downloaded.
Connects the board to your PC via USB cable. The board has two USB connectors, USB OTG and USB STLINK. Connect to USB STLINK.
Launch the terminal software and connect to the board. Here're parameters for serial connection:
| parameter | value |
|---|---|
| baud | 115200 |
| data bit | 8-bit |
| parity | none |
| stop bit | 1 |
| flow control | none |
Connecting your board to your PC, the board is recognized as a USB mass storage drive named DIS_L4IOT.
In the drive, you'll see the files DETAILS.TXT and MBED.HTM. Copy the downloaded firmware image file into the same directory. Then the firmware image is written into the micro controller on your board. While writing, an LED on your board blinks.
Right after the firmware image is written, the IoT device resets and the firmware runs automatically. The following is an example of serial output from the IoT device. The messages might be different on your environment.
[BOOT] Mbed Bootloader
[BOOT] ARM: 00000000000000000000
[BOOT] OEM: 00000000000000000000
[BOOT] Layout: 0 80082A0
[BOOT] Application's start address: 0x8010400
[BOOT] Application's jump address: 0x8011041
[BOOT] Application's stack address: 0x20018000
[BOOT] Forwarding to application...
{LStarting Simple Pelion Device Management Client example
Connecting to the network using Wifi...
Connected to the network successfully. IP address: 192.168.0.17
[SMCC] Autoformatting the storage.
[SMCC] Reset storage to an empty state.
[SMCC] Starting developer flow
Initialized Pelion Client. Registering...
Connected to Pelion Device Management. Endpoint Name: 0166e9235ab80000000000010010012c
At the end, the message like Connected to Pelion Device Management. Endpoint Name: XXXXXXXXXXXXXXXXXXXXXX should appear. If you can see this message, the IoT device has been connected to Pelion Device Management. Where, XXXXXXXXXXXXXXXXXXXXXX (0166e9235ab80000000000010010012c in the exapmle above) is the endpoint name (device ID), which is used later.
If you don't see any message on your terminal, push the RESET button, the black push button, on your board.
Let's confirm the IoT device is registered to Pelion Device Management on the portal site. Open this page:
If log in is requested, click the Log in with your Mbed.com account,
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then, click the Log in with Mbed.com button.
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Once logged in, Usage Dashboard appears. Click the Devices in Device Directory in the left menu, then you'll see device list. You should see the one you registered in the previous steps.
Click the device name, device details view is shown. Choose the RESOURCES tab in the device details view.
The resources registered in the device are shown. Find the button_count ( /3200/0/5501 ) resource. This resource is correspond to the UESR button, the blue push button, on your board.
Click the resource name. You'll see the resource value, i.e. button count. When you push the USER button, the IoT device count up the internal counter and send its value to Pelion Device Management. You'll see the updated value on the portal. Every your push, you should see the value is updated.
B-L475E-IOT01A Discovery board has various sensors. Let's enable some of them and monitor the values on the Pelion Device Management portal. To do that, we add sensor code to the firmware. Then update the firmware on the IoT device by OTA (Over-The-Air).
In this workshop, to save time for coding, sensor code is prepared and can be enabled by compile-time switch. To enable the sensor code, define ENABLE_SENSORS.
Find the line //#define ENABLE_SENSORS at the top part of main.cpp. The ENABLE_SENSORS macro is comment out by default, sensors are not enabled. To enable sensors, remove the // at the head of the line.
Then the sensor codes between #ifdef ENABLE_SENSORS and #endif /* ENABLE_SENSORS */ are enabled.
Update firmware on the IoT device by OTA (Over-The-Air) with the firmware modified in the previous step.
In the workshop, the IoT device is at your hand. You might feel no difference between via USB and via OTA. However, IoT devices will be deployed massive and wide area. It's not realistic to update one by one via USB by hand. OTA update is necessary for IoT.
Here, we use the online compiler to perform OTA update. You can do the same thing with Mbed CLI. If you'd like to use Mbed CLI, please refer .
To perform OTA firmware update, an update firmware image and manifest are needed. To create them, click the Publish Firmware Update in Pelion Device Management at the top of online compiler window.
Input name and description of this update. Description can be empty. Once you finished, click the Publish button.
Next, specify the private key file to sign the update firmware. Click the Choose File and specify the private key file private.key, which you download at the previous step. After specify it, click the OK button.
Manifest will be created and signed, and the manifest and firmware will be upload to the server.
Once this step is finished, click the Open Device Management Portal and open Pelion Device Management Portal.
The update firmware image and manifest were upload. Set up the firmware update next. After open the Pelion Device Management portal, you'll see wizard to create a campaign draft for firmware update.
In step 1, input name and description of this campaign. The name field is filled automatically. You can go with the default value. Description field can be empty. After input, click the Next button.
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In step 2, you select manifest. The uploaded manifest should be selected automatically. You just click the Next button.
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In step 3, you choose the device(s) to apply the firmware update. Click the Select device to see IoT devices list. Choose the IoT device which has the same device ID in the previous step.
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In the last step, confirm the campaign details. After check, click the Finish button. Then a campaign draft will be created.
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The campaign you created will be shown. Click the Start button to start the campaign.
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Once the campaign started, the status will be Active.
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The serial monitor of the IoT device shows progress of new firmware download.
Firmware download requested
Authorization granted
Downloading: [+++| ] 6 %
Once firmware is downloaded successfully, the status on the portal will change to Stopped: Threshold 100.00% reached..
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The IoT device verifies the downloaded firmware, then reboot automatically.
When the IoT device reboots, new downloaded firmware image will runs. Sensor values are periodically shown on the serial monitor.
Firmware download requested
Authorization granted
Downloading: [++++++++++++++++++++++++++++++++++++++++++++++++++] 100 %
Download completed
Firmware install requested
Authorization granted
[BOOT] Mbed Bootloader
[BOOT] ARM: 00000000000000000000
[BOOT] OEM: 00000000000000000000
[BOOT] Layout: 0 80082A0
[BOOT] Active firmware integrity check:
[BOOT] [++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++]
[BOOT] SHA256: 0920D91DFB42DC010ED57AAE1402B807BD1BA53DD0D5B6808265932331E12015
[BOOT] Version: 1541509308
[BOOT] Slot 0 firmware integrity check:
[BOOT] [++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++]
[BOOT] SHA256: 0B831833F4714A85BAE5006C03248FCC0353487BE6EBE8F59BFB67861494B64C
[BOOT] Version: 1541514141
[BOOT] Update active firmware using slot 0:
[BOOT] [++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++]
[BOOT] Verify new active firmware:
[BOOT] [++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++]
[BOOT] New active firmware is valid
[BOOT] Application's start address: 0x8010400
[BOOT] Application's jump address: 0x8011041
[BOOT] Application's stack address: 0x20018000
[BOOT] Forwarding to application...
{LStarting Simple Pelion Device Management Client example
Invalid new address!
Connecting to the network using Wifi...
Connected to the network successfully. IP address: 192.168.0.17
[SMCC] Starting developer flow
[SMCC] Developer credentials already exist
Initialized Pelion Client. Registering...
Connected to Pelion Device Management. Endpoint Name: 0166e9235ab80000000000010010012c
VL53L0X [mm]: 304
Sensor resources are added on the device resource list in Pelion Device Management Portal. For example, distance resource. Clicking it, the value of the distance sensor on the IoT device is shown.
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Here shows OTA update steps with Mbed CLI, not online compiler. Supposed that the latest Mbed CLI is already installed into your PC. About Mbed CLI, please refer to GitHub repository of Mbed CLI.
Execute the following command from your command line. The $ at the head of lines are marker, and you don't have to input.
$ mbed import https://github.com/coisme/Pelion-DM-Workshop-Project
The target project will be imported with the directory name Pelion-DM-Workshop-Project. Move to this project root.
$ cd Pelion-DM-Workshop-Project
To interact with Pelion Device Management from Mbed CLI, you need an API key. Refer to Generating an API key page.
Set up your API key and build toolchain.
$ mbed config -G CLOUD_SDK_API_KEY <API_KEY>
$ mbed target DISCO_L475VG_IOT01A
$ mbed toolchain GCC_ARM
Next, generate necessary files to connect your IoT device to Pelion Device Management.
$ mbed dm init -d "example.com" --model-name "PELION_DEMO" -q --force
Please refer to the section Set Up Wi-Fi Access Point.
Create IoT device's firmware by building the project. Execute the following command and build the project. It may take a few minutes.
$ mbed compile
Once built successfully, you'll see the message like this:
| Module | .text | .data | .bss |
|-------------------------------------------------------|----------------|------------|-------------|
| VL53L0X/VL53L0X.o | 26(-12402) | 0(-697) | 0(+0) |
| [fill] | 766(+2) | 13(+1) | 108(+4) |
| [lib]/c.a | 56430(+0) | 2548(+0) | 127(+0) |
| [lib]/gcc.a | 7460(+0) | 0(+0) | 0(+0) |
| [lib]/misc | 252(+0) | 16(+0) | 28(+0) |
| [lib]/nosys.a | 32(+0) | 0(+0) | 0(+0) |
| [lib]/stdc++.a | 8478(+0) | 44(+0) | 204(+0) |
| main.o | 2313(-830) | 4(+0) | 232(-724) |
| mbed-os/components | 5694(+70) | 0(+0) | 0(+0) |
| mbed-os/drivers | 3594(-452) | 4(+0) | 184(-44) |
| mbed-os/events | 1855(+0) | 0(+0) | 3144(+0) |
| mbed-os/features | 120419(+22) | 191(+0) | 7842(+0) |
| mbed-os/hal | 2061(+0) | 4(+0) | 68(+0) |
| mbed-os/platform | 5351(+0) | 272(+0) | 646(+0) |
| mbed-os/rtos | 13512(+0) | 168(+0) | 6969(+0) |
| mbed-os/targets | 19806(-5065) | 8(+0) | 1457(-20) |
| mbed_cloud_dev_credentials.o | 1525(+0) | 0(+0) | 0(+0) |
| simple-mbed-cloud-client/mbed-cloud-client | 123464(+0) | 416(+0) | 5865(+0) |
| simple-mbed-cloud-client/mbed_cloud_client_resource.o | 1298(+0) | 0(+0) | 0(+0) |
| simple-mbed-cloud-client/resource.o | 699(+0) | 0(+0) | 0(+0) |
| simple-mbed-cloud-client/simple-mbed-cloud-client.o | 3364(+0) | 0(+0) | 8(+0) |
| simple-mbed-cloud-client/update_ui_example.o | 456(+0) | 0(+0) | 6(+0) |
| update_default_resources.o | 460(+0) | 0(+0) | 0(+0) |
| wifi-ism43362/ISM43362 | 7734(+0) | 0(+0) | 0(+0) |
| wifi-ism43362/ISM43362Interface.o | 4189(+0) | 0(+0) | 964(+0) |
| Subtotals | 391238(-18655) | 3688(-696) | 27852(-784) |
Total Static RAM memory (data + bss): 31540(-1480) bytes
Total Flash memory (text + data): 394926(-19351) bytes
Update Image: ./BUILD/DISCO_L475VG_IOT01A/GCC_ARM/Pelion-DM-Workshop-Project_update.bin
Image: ./BUILD/DISCO_L475VG_IOT01A/GCC_ARM/Pelion-DM-Workshop-Project.bin
The last two lines are the relative path of generated firmware images. The first one is for firmware update. The second one, contains boot loader, is for initial setup.
The same steps as online compiler. Refer to the links below. Use ./BUILD/DISCO_L475VG_IOT01A/GCC_ARM/WS_ET-IoT-Expo-2018.bin as the downloaded firmware image.
- Connect Board to PC
- Connect Serial Monitor
- Write Firmware Image
- Run IoT Device
- Confirm on Pelion Device Management
The same steps as online compiler. Refer to the link below.
Rebuild the project and create firmware image for update. Execute the following command:
$ mbed compile
Let's perform OTA firmware update. Here, you need replace <device ID> with the device ID of your connected device.
$ mbed dm update device -D <device ID> -m DISCO_L475VG_IOT01A
Progress of firmware download appears on your serial monitor.
Firmware download requested
Authorization granted
Downloading: [+++| ] 6 %
Once download done and verify the download stuff, the IoT device reboots automatically.
To check if the IoT device is update successfully, please refer the section Check Updated