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STM32
Not long after WiFi6.0 (IEEEax) introduced 1024QAM modulation + downlink OFDMA + TWT + 160MHz bandwidth, its successor WiFi7.0 (IEEE802.11be) came with 4096-QAM + 320MHz bandwidth + 6GHz, setting off a new round. IoT revolution.
As a 2.4G wireless technology standard, Bluetooth is
also changing with each passing day. Bluetooth 5.0 introduces 2M PHY+247B MTU, Bluetooth 5.1 introduces AoA/AoD antenna I/Q angle positioning, and Bluetooth 5.2 introduces the LC3 encoding for LEAudio that has been used in hearing aids for ten years. , Bluetooth 5.3 introduces enhanced GATT, and the recent Bluetooth 5.4 introduces periodic broadcast features for ESL electronic price tags. Each development is a very interesting topic. Therefore, in addition to separate WiFi and Bluetooth chips, there are also many WiFi+Bluetooth coexistence SoC, STM32WB series is officially such a new generation of wireless SoC.
As a result, Bluetooth can be seen everywhere in shared bicycles, QR code-scanning washing machines, subway indoor maps, turnstiles, car keys, etc. Bluetooth SIG has also released many profiles, such as heart rate, blood oxygen, pedometer, blood pressure, etc. in the health field, and is close to the service field. , location, time, power, etc. The emergence of mesh breaks the traditional one-to-eight Piconet and Scatternet, and introduces Ad-Hoc routing and publish/subscribe mechanisms, which greatly broadens the breadth of the Internet of Things.
Why use STM32WB55 to experience power Internet of Things applications?
Engineers who have worked in industrial control are familiar with STM32, and are involved in general computing, industrial control, AI, MPU, security, etc. The wireless product
S
TM32WB55
appeared as early as the 2019 Shenzhen Bluetooth Asia Conference.
As an engineer in the power industry, recent R&D projects are highly relevant to the power Internet of Things industry. In addition to the topics of carbon neutrality, green new energy, smart grids, and electric vehicles, various AMI meter reading meters, meter reading terminals, etc. are all State Grid standard equipment requiring local maintenance of Bluetooth, infrared, RS485, HPLC carrier and other channels, among which Some power equipment does not provide external communication interfaces for safety reasons. At this time, meter reading and upgrading through Bluetooth come in handy. For example, the recently developed IoT meter integrates metering, ESAM security and cost control, storage, clock, display, communication, etc. It adopts the DLT698.45 protocol and can be upgraded or maintained through Bluetooth to facilitate debugging and maintenance. This article uses the STM32WB55 Bluetooth board to experience its Bluetooth features, transplant the IAP upgrade framework, experience its speed, capture packets, and then experience interoperability and mesh performance with existing Realtek or other Nordic platforms.
DTM RF & ACI Event Testing
This evaluation involves the controller's HCI instructions, scripts, Bluetooth protocol stack, CW carrier frequency, signal noise, etc., mainly from the ACI Utilities master-slave test, RF Test transceiver error test, Beacon connectionless test, script test ( Issuing HCI commands) a series of STM32CubeMonitor-RF radio frequency integration toolset to expand, I will not go into details.
Test environment preparation
The STM32Cube series tools are fully functional:
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name
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Function
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STM32CubeProgrammer
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Writer
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STM32CubeMonitor
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Graphical low-code process editor
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STM32CubeMonitor-RF
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RF testing
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STM32CubeIDE 1.12.1
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editor
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STM32CubeMX
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Graphical code generator
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Since this evaluation requires burning transparent mode HCI firmware and radio frequency testing, the software environments STM32CubeProgrammer and STM32CubeMonitor-RF must be installed first. The hardware environment is as follows:
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board
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serial number
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serial port
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P-Nucleo-WB55
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MB1355C-02 Nucleo board
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ST-Link Virtual COM
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P-Nucleus-WB55
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MB1293C-02 dongle
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USB serial port COM
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Figure 1
STM32WB55 Dongle and Nucleo board
After installation, the STM32WB Nucleo Board needs to burn the transparent mode firmware. For the path, see STM32Cube_FW_WB_V1.16.0\Projects\P-NUCLEO-WB55.Nucleo\Applications\BLE\BLE_TransparentMode\Binary\BLE_TransparentMode_reference.hex; similarly, the STM32WB Dongle also needs to be burned. Transparent mode firmware, see STM32Cube_FW_WB_V1.16.0\Projects\P-NUCLEO-WB55.USBDongle\Applications\BLE\BLE_TransparentModeVCP\Binary\BLE_TransparentModeVCP_reference.hex for the path. Since the STM32WB55 dongle does not lead to an interface such as Jlink ISP, IAP programming is required. Specifically, unplug the power, turn the SW2 toggle switch to the boot0 position and plug it in again. Open the STM32CubeProgrammer. Although there is a serial port, you should switch to USB and select The above files can be burned; STM32WB55 has on-board ST-Link, which makes burning much simpler. You can use the early ST-link Utility or the later replacement STM32CubeProgrammer to burn. You only need to select the ST-Link connection method, or you can For project burning, see the project folder.
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Figure 2.1 STM32WB55 Nucleo board (MB1355C-02) burning test firmware
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Figure
2.2 STM32WB55 Dongle (MB1293C-02) burning test firmware
Open STM32CubeMonitor-RF and you can see that it supports IEEE 802.15.4 (ZigBee/Thread) and BLE. This article only discusses BLE. Just click on BLE. After entering, if the firmware is not burned correctly and the connection is made, the error "STM32Cube device under test not responding" will be reported:
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Figure 3 STM32CubeMonitor-RF Lanuch Splash page
ACI Utilities master and slave test
1. Broadcast test
Check Advertising, you can see the baseband fixed frequency, MAC address, broadcast channel parameters, etc. in the Bluetooth controller. Keep the default. After selecting, click START ADVERTISING. You can see the dongle's broadcast packet just now in the ST BLE Toolbox on the mobile phone. Also because the connection is an empty package, the Android side cannot read the attribute database and cannot connect. iOS can establish a connection:
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Figure 4.1 Broadcast test
2. Scan test
Check Discover remote service, you can see the transmission power, MAC address, etc. in the Bluetooth controller. Keep the default. After selecting, click STCAN to start capturing ADV_REPORT events. After stopping, you can select the scanned device connection in the Select Device drop-down box. , the connection here always prompts Could not connect peer error, it should be rejected by the server:
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Figure 4.2 Scan test
RF Test transceiver error test
1. Transceiver test
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Figure 5 Two STM32CubeMonitor-RF control interfaces for both sending and receiving parties
Open two STM32CubeMonitor-RF, connect one serial port to the STM32WB55 dongle to act as the sender, and connect the other serial port to the STM32WB55 Nucleo board to act as the receiver. Then click on the default configuration and click the START RX button of the receiver first, and then click the START of the sender. TX button. After finishing, click the STOP TX button on the sender first, and then click the STOP RX button on the receiver. Then you can see the statistics of sending and receiving packets displayed on it:
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Figure 6 Statistics of sending and receiving test packets
2. Error test
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Figure 7 An STM32CubeMonitor-RF display bit error rate interface on both sides of the sender and receiver
The result is the same as the above transceiver test, there is also a bit error rate of 0.81%, which needs to be investigated.
Beacon no connection test
iBeacon was very popular a few years ago, but now it is basically rare. You might as well fill in the Shake peripheral UUID, Major, and Minor that WeChat initially exited:
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UUID
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Major
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Minor
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FDA50693A4E24FB1AFCFC6EB07647825
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000A
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0007
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Figure 8 ibeacon no connection package test
script test
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Figure 9 Loading script file execution command
Those who have worked on the BlueZ protocol stack should be familiar with this. It mainly issues HCI commands to the lower layers, such as OCF and OGF domain settings. The first letter of the script command must be capitalized, otherwise an error will be reported. For detailed format, check the software manual, and for detailed instructions, check Core Spec. For example, if you set the device name to "Fengyun", you can fill in "0709E9A38EE4BA91" (little endian storage here), the effect is shown in the picture above.
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Figure 10 Example of script command parsing
The script content is as follows:
Send(HCI_RESET)
Wait(1000)
Send(ACI_HAL_SET_TX_POWER_LEVEL;0x00;0x1F)
Wait(1000)
Send(ACI_HAL_WRITE_CONFIG_DATA;0x00;0x06;0x665544332211)
Wait(1000)
Send(ACI_GATT_INIT)
Wait(1000)
Send(ACI_GAP_INIT;0x03;0x00;0x00)
Wait(1000)
Send(HCI_LE_READ_ADVERTISING_CHANNEL_TX_POWER;0x01;0x07;0x20;0x00)
Wait(1000)
Send(HCI_LE_SET_ADVERTISING_PARAMETERS;0x0800;0x0800;0x00;0x00;0x00;0x665544332211;0x01;0x00)
Wait(1000)
Send(ACI_GAP_SET_DISCOVERABLE;0x00;0x0080;0x00A0;0x00;0x00;0x07;0x91BAE48EA3E909;0x03;0x180d02;0x0000;0x0000)
Wait(1000)
Send(ACI_GAP_UPDATE_ADV_DATA;0x03;0x000A02)
Source: STM32 forum user MingXJ Copyright belongs to the original author
© THE END
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Figure 2.1 STM32WB55 Nucleo board (MB1355C-02) burning test firmware
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Figure
2.2 STM32WB55 Dongle (MB1293C-02) burning test firmware
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Figure 4.2 Scan test
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Figure 5 Two STM32CubeMonitor-RF control interfaces for both sending and receiving parties
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Figure 6 Statistics of sending and receiving test packets
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Figure 8 ibeacon no connection package test
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Figure 9 Loading script file execution command
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