Not only has Samsung maintained a high market share in the smartphone industry, it has also dominated the TV market for 14 consecutive years.
According to the latest report of the statistics agency Omdia, in the first quarter of this year, Samsung’s share of the global TV market reached a new high, accounting for 32.4%, an increase of 3.1% year-on-year, and maintained a share of more than 30% in the global TV market for four consecutive quarters. Not only has Samsung maintained a high market share in the smartphone industry, but it has also ranked first in the TV industry in terms of sales volume for 14 consecutive years.
Analysts said the market share was driven by rising sales of Samsung’s QLED TVs and other high-end TVs, with the South Korean company shipping more QLED TVs in the quarter, up 10.8 percent, to a total value of 2.05 billion. Dollar. Samsung currently has a 50.4% market share in the 75-inch (or larger) TV segment.
Due to the development of mobile devices such as smartphones, the TV industry is also gradually showing a downward trend.
The report shows that in the first quarter of 2020, global TV shipments were 46.5 million units, down 10.2 percentage points; total revenue was $20.6 billion, down 17.9 percent. It is worth noting that Samsung TV’s performance in North America and Europe is quite strong, with its market share accounting for 42.5% and 41.1% respectively. Among them, Samsung’s share of TV products above 75 inches is as high as more than half.
The data shows that LG Electronics, a brand also from South Korea, has a global market share of 18.7% in the first quarter of 2020, a year-on-year increase of 2.2 percentage points, ranking second. In addition, Sony TV sales ranked third.
Researchers recently discovered a new type of Android malware in Google Play that has affected more than a hundred banking and cryptocurrency apps.
Researchers at Dutch security firm ThreatFabric named the malware Vultur. The malware records the screen when the target application is open, and Vultur uses VNC screen sharing to mirror the compromised host’s screen to an attacker-controlled server.
A new era of fraud
The typical method of Android stealing malware is to overlay a transparent window or the same interface window as the target application on the login window of the target application. Collect users’ private information and transfer funds to another place.
Researchers at ThreatFabric found in Vultur:
“The stealth threat on mobile platforms is no longer based solely on the well-known overlay attack, but has evolved into remote-control-like malware that also inherits the traditional way of detecting foreground apps and starting screen recordings.”
This continues to push the threat to another level, Vultur’s attacks are scalable and automated, and fraudulent tactics can be scripted in the backend and delivered to the victim device.
Like many Android banking Trojans, Vultur relies heavily on accessibility services built into the mobile operating system. When first installed, Vultur abuses these services to gain the required permissions. Once installed, Vultur monitors all requests that trigger accessibility services.
Vultur uses these services to monitor requests from target applications, and malware also uses these services to remove and clean malware by general means. Vultur automatically clicks the back button whenever the user tries to access the application details page in Android settings. This prevents users from hitting the uninstall button, and Vultur also hides its own icon.
Another way Vultur stays hidden: The app that installs it is a full-featured app that actually offers real services, like fitness tracking or two-factor authentication. However disguised it is, the Vultur appears as a projected screen in the Android notification Panel, which exposes it.
After successful installation, Vultur will start screen recording using Alpha VNC’s VNC. To provide remote access to VNC servers running on infected devices, Vultur uses ngrok, an application that exposes local systems hidden behind firewalls to the public internet using an encrypted tunnel.
Vultur will be installed by the Dropper program, and ThreatFabric has found two dropper applications that install Vultur in Google Play. In total, over 5,000 devices were affected, and unlike other Android malware that relies on third-party droppers, Vultur uses a custom dropper known as Brunhilda.
Brunhilda was developed by the same group as Vultur, and Brunhilda has been used to install different Android banking malware in the past. In total, Brunhilda is estimated to have infected more than 30,000 devices.
Vultur targeted 103 Android banking apps or cryptocurrency apps, with Italy, Australia and Spain the most attacked.
In addition to banking apps and cryptocurrency apps, the malware collects credentials for Facebook, WhatsApp Messenger, TikTok, and Viber Messenger.
Google has removed all Googel Play apps known to contain Brunhilda, but Google says new Trojan apps may still appear. Android users should only install apps that provide a useful service, and whenever possible, only apps from well-known publishers.
Unmanned driving (aka autonomous driving) is humanity’s next decade’s plan. Achieving this dream requires a unique combination of technologies to overcome the overarching challenges of autonomous driving.
Autonomous vehicles (AVs) need to process large amounts of information in real time. For example, to avoid collisions, detect obstacles and pedestrians, and notify free parking spaces, vehicles need to exchange large amounts of metadata with urban infrastructure (e.g., traffic lights, public safety systems), fog/cloud service providers, and even car manufacturers. According to Intel statistics, the amount of data that such a car needs to process every day will be as high as 3.9TB, which is equivalent to the daily data usage of 2,666 netizens. Auto parts such as ultrasound, radar, GPS, cameras and infotainment systems are all contributing factors to this surge.
To ensure the secure and scalable data exchange of vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P) technologies collectively referred to as vehicle-to-vehicle (V2X) New standards were developed with organizations led by the Institute of Electronic Engineers and the U.S. Department of Transportation.
However, the V2X standard alone is not enough. In order for vehicles to make complex, autonomous decisions in real time without compromising road safety, V2X systems must be equipped with a mobile communication ecosystem whose speed and data processing capabilities can match human responses. Accidents involving autonomous driving road tests reported in recent years have further underscored this requirement, for which the 3rd Generation Partnership Project (3GPP) developed the 5G wireless standard.
How 5G fits into V2X use cases
A common feature of AVs is the ability to continuously perceive the observed environment to select driving routes in real time. In bandwidth-constrained radio environments, they must be able to handle high levels of noise and interference as well as highly dynamic configurations of external entities. To support V2X use cases, increasing data throughput alone is not enough. In addition, the network infrastructure must be able to provide a highly reliable low-latency network and ensure data security across different communication ranges.
The realization of the following common V2X use cases will eventually lead the car into the era of fully connected automation:
Co-awareness (eg, emergency vehicle alerts);
Collaborative perception (exchange original perception data);
Cooperative maneuvering (coordinating vehicle routes in lane changing, queuing, intersection control, etc.);
Notifying vulnerable road users, i.e. pedestrians, cyclists, etc.;
To support these use cases, more than one wireless technology may be required, such as short-range direct communication between devices (V2V, V2I, and V2P) without scheduling over the network. Device-to-device interfaces with 3GPP Release 12/13 LTE Proximity Services technology can be used to reliably transmit large amounts of data between adjacent vehicles with ultra-low latency. For vehicle-to-network (V2N) communications, not only traditional cellular cloud services, but also new 5G wireless technologies are needed.
Connectivity and Network Performance
Large-scale data and devices are the biggest challenges in the era of autonomous driving. Compared with 4G/LTE, 5G has a 1,000-fold increase in bandwidth per unit area, a 10,000-fold increase in traffic, and a 100-fold increase in the number of connected devices per unit area. 5G small cell technology using mmWave has higher spectral efficiency, which is a big advantage for bandwidth-constrained V2X environments.
5G promises ultra-low latency >1ms, meeting reliability expectations for mission-critical V2X use cases. Relatively speaking, wireless data is easier to intercept and more vulnerable to man-in-the-middle attacks. 5G promises to improve the security of 5G electronics by including mutual authentication, local secure elements, transport layer security, 99.999% network availability, and firmware over-the-air updates.
Like virtual machines on virtualized hardware platforms, 5G’s network slicing capabilities allow different vendors to offer different classes of automotive services over the same infrastructure. For example, it will allow telecom operators, road operators and automakers to offer different services to vehicles and their passengers on the same 5G infrastructure.
5G V2X Requirements and Design Considerations
In order to connect vehicles and back-end infrastructure, 5G V2X applications impose new design requirements on communication systems, so the 5G V2X specification was developed in 3GPP Release 16.
Industry forums such as 3GPP and the 5G Automotive Association have identified use-case-specific performance requirements for 5G V2X systems in terms of latency, reliability, and data rates. 3GPP has identified the following five categories of requirements for 5G V2X:
General purpose: applicable to interconnection and communication related requirements of all V2X scenarios
Vehicle queuing: Vehicles traveling slowly with ultra-fine spacing
Advanced driving: semi-autonomous or fully autonomous driving
Extended sensors: information exchange between all V2X-enabled devices and network elements
Remote driving: controlled remotely by the driver (e.g. in hazardous environments)
It is important to note that the requirements for a 5G V2X system depend on the use case scenario (Figure 1). Routine lane change maneuvers require far less latency and reliability than coordinated maneuvers in emergency situations.
Figure 1: This graph shows V2X latency and data rate requirements for 5G as defined in 3GPP guidelines, fine-tuned based on input from automotive OEMs (Source: Use Cases, Requirements, and Design on arxiv.org Considerations for 5G/V2X)
AVs are essentially mobile data centers; they rely heavily on edge computing Power. It would take about 230 days to transmit a week’s worth of data from a self-driving car over an advanced Wi-Fi connection. Therefore, disruptive innovations in product and application-specific integrated circuit processing technologies for new radio and antenna architectures are critical to support 5G V2X.
The digital Power controller UCD3138 integrates 4 digital comparators, which can flexibly configure its input terminals and reference values. The absolute value of the analog front end (AFE) module and the output of the EADC can be used as the input of the digital comparator, so the use of the digital comparator can realize the fault response and protection of the system output voltage. UCD3138 integrates 16 analog-to-digital converters (ADCs), among which the analog-to-digital converter named ADC15 is not open to the outside, and can be used to detect the EAP or EAN pins of any one of the three AFE modules to realize the system output voltage The accurate acquisition of the output voltage can finally realize the fault response and protection of the output voltage.
1,UCD3138 the digital comparator
The UCD3138 integrates 4 digital comparators, which can use the absolute value or error value of the AFE as the input terminal to configure the reference value flexibly, and finally achieve fast response and protection to system output voltage faults (overvoltage, undervoltage, etc.).
1.1 Introduction to the hardware circuit of the digital comparator
Figure 1 shows the block diagram of the analog front end (Analog Front End, AFE) inside the UCD3138 chip. The output voltage enters the AFE module in the form of a differential signal after voltage division, and compares it with the reference voltage (the output value of DAC0) to obtain an error signal (analog quantity); the error signal becomes a digital quantity after analog-to-digital conversion, and then input to the digital loop compensation module (Filter).
Figure 1. UCD3138 AFE Block Diagram
In order to enrich the flexibility of the application, the reference value (digital value) set by the user is added to the output value (digital value) of the EADC to generate a digital signal called “absolute value”, which can represent the actual collected value. Voltage information (ie the value of Vd).
The digital comparator of UCD3138 is composed of digital error signal (point B value) or absolute value (point C value) as one input, and reference voltage value (can be set by the user) as another input, which can be configured after triggering It shuts down any DPWM.
There are 3 AFE modules in UCD3138, and similarly, there are 4 digital comparators.
1.2 Key registers involved in digital comparators
1.2.1 EADC output
The output of EADC is the information amount after digitization of the value after subtracting the reference voltage and the input analog amount, that is, the digital error amount, the range of which is directly related to the gain of the AFE itself. For example, when the gain value is set to 1, the output range is +248~-256; and when the gain value is set to 8, the output range is +31~-32.
The 0~8th bits (9 bits in total, named RAW_ERROR_VALUE) of the register EADCRAWVALUE save the output of the EADC with a resolution of 1mV/bit.
1.2.2 Input of DAC
The output of the DAC is the reference voltage of the system. In the practical application of UCD3138, the user can set the input value of the DAC to be a digital signal. The 4th to 13th bits of the register EADCDAC (10 bits in total, named DAC_VALUE) save the user’s setting value. The resolution is 1.5625mV/bit.
1.2.3 Absolute value quantity
The 16th to 25th bits of the register EADCVALUE (10 bits in total, named ABS_VALUE) store the absolute value with a resolution of 1.5625mV/bit.
As mentioned above, the absolute value is obtained by adding the output information of the EADC and the input information of the DAC, but it is not the direct addition of the two digital quantities because their resolutions are different. In fact, there is an equality relationship between the analog quantities represented by the above three digital quantities.
For example, under certain conditions, the output of EADC (ERROR_VALUE) is 192; the input of DAC is 747; the absolute value (ABS_VALUE) is 624, as shown in Figure 2 below.
Figure 2. Memory Debugger register value read in
Obviously, 747-624=123≠192. However, the respective analog quantities satisfy the equation relationship as follows:
► The analog quantity corresponding to the output 192 of the EADC is 192×1mV/bit=192mV;
► The analog quantity corresponding to the input 747 of the DAC is 747×1.5625mV/bit=1167.1875mV;
► The analog quantity corresponding to absolute value 624 is 624×1.5625mV/bit=975mV;
◎Finally, 1167.1875-975=192.1875≈ 192.
Alternatively, the three digital quantities can have the following equation relationship after increasing the attenuation coefficient:
1.3 Software Configuration of Digital Comparator
During the initialization phase of the program, the configuration of the digital comparator can be completed. Taking the configuration of digital comparator 0 as an example, the main code is as follows:
FaultMuxRegs.DCOMPCTRL0.bit.CNT_THRESH = 1;
The above code configuration only needs to trigger the digital comparator once to generate a fault.
FaultMuxRegs.DCOMPCTRL0.bit.FE_SEL = 0;
The above code configures the input of the digital comparator to be the absolute value of AFE0. Can also be configured as an EADC output. In addition, the absolute value of the remaining two AFEs and the output of the EADC can also be configured as digital comparator 0 inputs.
FaultMuxRegs.DCOMPCTRL0.bit.COMP_POL = 1;
The above code is configured to trigger when the input of the digital comparator is higher than the reference.
FaultMuxRegs.DCOMPCTRL0.bit.THRESH = 850;
The reference volume is set to 850. If the input quantity is selected as the absolute value quantity, the digital comparator will be triggered when the Vd voltage is greater than 850×1.5625mV/bit=1.33V.
The above code is configured to shut down DPWM0A and DPWM0B immediately after the digital comparator is triggered.
1.4 Practical Application Results of Digital Comparator
During actual debugging, an external adjustable voltage is connected to Vd in Fig. 1, and gradually increases from 0V. It can be observed that when the voltage exceeds 1.33V, the driving signal is immediately turned off, as expected, as shown in Figure 3 below (CH3 is Vd voltage, CH2 is DPWM0B).
Figure 3. Digital Comparator Closes After TriggeringDPWM0B
1.5 Practical Application Results of Digital Comparator
Need to pay attention to the saturation problem of EADC in practical application.
As mentioned in Section 1.2 above, the output of the EADC has a certain range. When the input is too large or too small, the output of the EADC will be fixed at its upper or lower limit. At this time, the EADC is in a saturated state. Still in the context of the experiment mentioned above, where the gain of the AFE is set to 1.
When the Vd voltage is 554mV, the absolute magnitude is expected to be 355 (since 554/1.5625 ≈ 355) and the output of the EADC is expected to be 613 (refer to the equation at the end of Section 1.2). The actual reading found that the absolute value is 588, and the output of the EADC is 248, which is completely different from the assumption. Analysis of the reasons shows that the EADC is already in positive saturation at this time, and the upper limit of the output is 248.
Figure 4. EADC positive saturation
Likewise, when the Vd voltage is 1.64V, the absolute magnitude is expected to be 1050 (since 1640/1.5625 ≈ 1050) and the output of the EADC is expected to be -473 (refer to the equation at the end of Section 1.2). The actual reading found that the absolute value is 911, and the output of the EADC is -256, which is completely different from the assumption. It can be known from the analysis of the reason that the EADC is already in negative saturation at this time, and the lower limit of the output is -256.
Figure 5. EADC negative saturation
Based on the above analysis, it can be seen that after the value of the DAC is fixed, there is a range of absolute value, which is directly related to the gain of the AFE, as shown in the following table.
Table 1. Absolute value range andAFE gain relationship
It can be observed that if the gain of AFE is set to 8 and the value of DAC is 747, the range of absolute value is 727~767. At this point, if you plan to have the digital comparator trigger when Vd is 1.33V, its reference needs to be set to 850. However, the other end of the digital comparator (where the input is an absolute value) only maxes out at 767, so the digital comparator will have no chance to be triggered.
In practical applications, the gain of the AFE needs to be considered when setting the reference value of the digital comparator to prevent the digital comparator from being unable to trigger due to the early saturation of the EADC, which causes its output to be clamped.
2,UCD3138 The internal analog-to-digital converterADC15
There are 16 analog-to-digital converters in the UCD3138 chip, of which ADC15 can be connected to the EAP or EAN pins of the AFE module inside the chip. In practical applications, ADC15 can be used to detect the feedback voltage of the system, and the actual output voltage can be restored in software.
2.1 ADC15 Configuration
The ADC15 inside the UCD3138 chip can be connected to the EAP or EAN pins of any AFE module to complete the digitization of the analog signal. In application, the configuration is very similar to other ADCs, the only difference is that ADC15 needs to be configured to the specified AFE.
The following three lines of code complete the association between ADC15 and AFE. Among them, AFE_MUX_CH_SEL is 1 means ADC15 is connected to AFE0; AFE_VIN_MUX is 0 means ADC15 is connected to EAP pin.
Combining the above configuration, ADC15 is connected to the EAP pin of AFE0, that is, the Vd voltage in Figure 1 can be detected.
2.2 Experimental results
As shown in Figure 4, when Vd is 554mV, the result of ADC15 (adc_values.Vout) is 902. The two approximately conform to the following equation:
As shown in Figure 5, when Vd is 1.64V, the result of ADC15 (adc_values.Vout) is 2681. The two approximately conform to the following equation:
The difference between the above physical values and digital quantities is mainly caused by measurement errors.
3,UCD3138 The internal analog-to-digital converterADC15
Both the digital comparator and the analog-to-digital converter ADC15 in the UCD3138 chip can be used to deal with the work related to the output voltage.
Among them, after the digital comparator is configured, it can realize fast response and protection to the output voltage overvoltage or undervoltage; after the ADC15 is configured, the output voltage information can be accurately collected, and then the fault protection of the output voltage can also be realized with the help of software design.
1. UCD3138 datasheet, Texas Instruments Inc.
2. UCD31xx Fusion Digital Power Peripherals Programmer’s Manual, Texas Instruments Inc.
3. UCD31xx Miscellaneous Analog Control _MAC_, Texas Instruments Inc.
Leon Micro recently announced that according to the company’s overall business development strategic plan, the company signed the “About Microwave Radio Frequency Integrated Circuit” on December 24, 2020 in Haining City, Zhejiang Province with the People’s Government of Haining City, Zhejiang Province and the Management Committee of Haining Economic Development Zone, Zhejiang Province. Chip Project Investment Agreement”, the name of the investment project is “Microwave Radio Frequency Integrated Circuit Chip Project”.
The company plans to register and establish Haining Leon Dongxin Microelectronics Co., Ltd. (tentative name, subject to the approval of the market supervision department, “Haining Company”) in Haining Economic Development Zone, Zhejiang Province, with a registered capital of 500 million yuan, and is specially responsible for promoting , to implement the investment projects.
According to reports, the total investment of the microwave radio frequency integrated circuit chip project is about 4.3 billion yuan, of which equipment investment is 3.605 billion yuan. After completion, it will produce 360,000 6-inch gallium arsenide/gallium nitride microwave radio frequency integrated circuit chips annually. These include an annual output of 180,000 gallium arsenide HBT and pHEMT chips, an annual output of 120,000 vertical cavity surface emitting laser VCSEL chips, and an annual output of 60,000 gallium nitride HEMT chips.
The project is implemented by Haining Company, a wholly-owned subsidiary of the company, in phases within five years, of which 180,000 pieces/year are constructed in the first phase and 180,000 pieces/year are constructed in the second phase. The product structure and implementation progress should be adjusted appropriately according to the market.
Home networking expert Devolo has added a new update to his Android Home app to control home controls. Devo Home Control System provides DIY solutions for people who want to use practical, safe and energy efficient home automation products. With the latest app update, Android users can easily control their smart home. With the latest update, the app can be configured to install the Home Control widget on the Android home screen, allowing faster access to Home Control’s main functions.
Topics of this press release:
New Android widgets improve speed and convenience
Improved feedback feature
devolo home control: more comfort, convenience, safety and energy saving
Now faster and more convenient
The latest update to the Android app makes the operation of your home control system faster and more convenient. Now, users don’t even need to launch the Home Control app to access many features.
Swiping from top to bottom, users can access device, scene, rule, group and time control settings directly from the home screen dashboard. In the Home Control widget, Android users can turn these icons on or off by simply touching the corresponding icons or functions of the smart device (scene, rules, time control settings), or quickly adjust the radiator to the desired temperature, for example. .
Users can decide which devices, scenes, rules, groups, or time control settings are displayed on the widget to quickly access multiple functions, such as adjusting the thermostat, activating an alarm, turning off all light bulbs for sleep or checking if any windows are closed.
The operation of the widget does not require much battery Power. If it is not used for a long time, it will switch to sleep mode and use less energy.
Last but not least, widgets can be permanently displayed on the screen. This is very useful, especially when combined with an Android tablet. If the tablet is installed in a central location in an apartment or house, all users can quickly and easily access Home Control.
Improved feedback feature
With the new update, users can easily, quickly and conveniently turn on or off desired elements, including adapters, scenes, rules, groups and time control settings, by clicking on the icons. The Android app also now provides better feedback when playing home control scenes. Users will also receive visual feedback in the app during scene playback.
devolo home control: more comfort, convenience, safety and energy saving
devolo home control is a comprehensive smart home solution developed in Germany. Currently, it consists of twelve different components. The starter kit with home control central unit, door/window contacts and smart metering plug is priced at £179.99 (RRP) (€203.87).
Compatible products from third-party vendors can also be integrated into the system. In principle, this includes all Z-Wave certified devices and Philips HUE smart lighting controls. This means that users can use hundreds of products to make a personalized smart home. Home Control can be controlled from the Home Control app and my devolo online portal.
The first RISC-V World Conference China (RISC-V World Conference China) will be held at ShanghaiTech University from June 21 to 27, 2021. Qinheng Microelectronics was invited to participate in this summit.
As a strategic member of the RISC-V International Foundation, Qinheng Microelectronics provides a wide range of RISC-V series MCUs based on self-developed technologies such as “one core and three interfaces”, aiming at the application of interconnection of all things and upper and lower interconnection.
• Booth: A3
• Time: June 22~24, 2021
•Keynote speech: RISC-V for embedded MCU and its development – June 22, 2021 14:40
Introduction to RISC-V China Summit
The summit is jointly sponsored by ShanghaiTech University and the Institute of Software, Chinese Academy of Sciences, co-organized by China RISC-V Industry Alliance (CRVIC), China Open Command Ecosystem Alliance (CRVA), and CNRV Community. The World Conference with the theme of RISC-V. This is also the first time RISC-V has hosted a summit of this scale outside of North America.
Qinheng Microelectronics’ RISC-V implementation and development for embedded MCU
Since its establishment, Qinheng Microelectronics has developed MCU for more than ten years, from self-developed 8-bit RISC core, self-developed E8051 to MCU with ARM and other cores.
In recent years, combined with the design experience of USB3.0, low-Power Bluetooth, Gigabit Ethernet and other interfaces, in-depth research on the RISC-V instruction set, optimization in practical application directions such as compressed instruction set, hardware stacking, fast interrupt, etc. Developed a variety of RISC-V core IP, and launched an enhanced version of MCU+ based on 32-bit general-purpose MCU architecture plus professional interface modules such as USB high-speed phy, Bluetooth transceiver, Ethernet phy, etc., further expanding RISC-V in low power consumption, wireless communication , high-speed transmission and other applications in embedded environments.
Qinheng Microelectronics is looking forward to meeting you at the first RISC-V China Summit!
June 25, 2021 – Mouser Electronics, a distributor of Electroniccomponents focused on introducing new products and offering extensive inventory, announced the signing of a global distribution agreement with M5Stack. M5Stack is a technology company dedicated to developing stackable open source Internet of Things (IoT) development kits. Under the agreement, Mouser will provide customers with M5Stack’s innovative development kits and tools to help designers quickly realize ideas and build new IoT prototypes. M5Stack’s development kit supports applications such as wearables, smart home devices, and IoT end controllers.
The Core2 ESP32 IoT Development Kit integrates an Espressif ESP32 microcontroller with Wi-Fi and Bluetooth, which houses two individually controllable Tensilica Xtensa 32-bit LX6 microprocessors. Featuring 16MB of onboard flash and 8MB of PSRAM memory, the Core2 kit supports a range of IoT applications including smart home devices. The versatile Core2 development kit features a built-in speaker, vibration motor, Power indicator, I²S amplifier, RTC and capacitive touchscreen.
Also powered by the Espressif ESP32 microcontroller, the M5StickC development tool is an easy-to-use, portable, open-source development tool that helps reduce development hurdles and shorten time-to-market for IoT devices. The M5StickC device has a built-in 6-axis inertial measurement unit (IMU), infrared transmitter, red LED, microphone and other peripherals. This development tool supports applications such as science, technology, engineering and math (STEM) education and DIY projects.
The ATOM Matrix ESP32 Development Kit features a 240 MHz dual-core ESP32 Pico with integrated Bluetooth and Wi-Fi technology in a compact 24 mm × 24 mm package. This ATOM kit features a built-in MPU6886 inertial sensor, 4MB of integrated SPI flash, and extensive customizable GPIOs, enabling rapid development of tiny embedded devices.
M5Stack’s BASIC ESP32 Development Kit is a modular, stackable and scalable development tool that provides an affordable solution for full-featured product development at all stages. Featuring built-in speakers, buttons, color LCD, power/reset buttons and a 16 GB TF card slot, the kit supports multiple applications such as IoT terminal controllers and DIY creations.
As a global authorized distributor, Mouser Electronics has a rich inventory of semiconductors and electronic components, and actively introduces new products from the original factory to support shipments at any time. Mouser aims to supply customers with fully certified OEM products with full manufacturer traceability. To help customers accelerate their designs, the Mouser website provides a rich library of technical resources, including technical resource centers, product data sheets, vendor-specific reference designs, application notes, technical design information, design tools, and other useful information.
“Bluetooth is a short-range radio frequency communication connection originally designed to replace the cables used to connect fixed or portable Electronic devices. Bluetooth devices operate in the Industrial, Scientific and Medical (ISM) frequency band of 2.4GHz which does not require a license. The Bluetooth baseband protocol supports both circuit-switched and packet-switched communications, and uses Frequency Hopping Spread Spectrum (FHSS) technology for transmission. In most areas of North America and Europe, Bluetooth devices work in the frequency band of 2.402 to 2.480 GHz, and the entire frequency band is divided into sub-channels with a bandwidth of 79.1 MHz.
Author: Lu Jiawei
1 Background of Bluetooth technology
Bluetooth is a short-range radio frequency communication connection originally designed to replace the cables used to connect fixed or portable electronic devices. Bluetooth devices operate in the Industrial, Scientific and Medical (ISM) frequency band of 2.4GHz which does not require a license. The Bluetooth baseband protocol supports both circuit-switched and packet-switched communications, and uses Frequency Hopping Spread Spectrum (FHSS) technology for transmission. In most areas of North America and Europe, Bluetooth devices work in the frequency band of 2.402 to 2.480 GHz, and the entire frequency band is divided into sub-channels with a bandwidth of 79.1 MHz.
The architecture of the Bluetooth protocol is divided into three parts: the underlying hardware module, the intermediate protocol layer and the high-level application. The underlying hardware part includes radio frequency hopping (RF), baseband (BB) and link management (LM) parts. They respectively define the requirements that the bluetooth transceiver must meet in the 2.4GHz frequency band to transmit information frames in a frequency hopping manner, and to establish or dismantle the transmission link connection, as well as the security and control of the link. The middle protocol layer includes Logical Link Control and Adaptation Protocol (L2CAP), Service Discovery Protocol (SDP), Serial Port Emulation RFCOMM and Telephone Communication Protocol (TCS). They respectively complete data disassembly, service quality control, protocol multiplexing, discovery of available services and service characteristics in the network, emulation of R-232 serial ports, and call control signaling for voice and data between Bluetooth devices. A Host Controller Interface (HCI) is defined between these two layers. This is the interface between software and hardware in the protocol. The protocol software entities above this layer run on the host, and the functions below the HCI are completed by the Bluetooth device. At the top of the protocol architecture is the high-level application framework (Profiles). At present, only conventional applications such as dial-up networking, headsets, LAN access, and file transfer are specified, and will continue to increase in the future. Various applications can realize wireless communication through their corresponding Profi1e.
Under the support of this standard, the Bluetooth system supports point-to-point and point-to-multipoint connections, and each Bluetooth system can connect more than 200 Bluetooth devices. The transmission characteristic of the Bluetooth system is to transmit information in a simplex or full-duplex manner in the ISM 2.4GHz frequency band that is freely used in the industrial, scientific and medical fields. The bandwidth of each Bluetooth channel is 1MHz, and it supports three synchronous data channels or one synchronous data channel and one asynchronous data channel at the same time. The data transmission rate of each synchronous data channel is 64kb/s, which is used for the transmission of voice data; the transmission rate of the asynchronous data channel is 721 kb/s downstream and 57.6 kb/s upstream, which is used for the transmission of digital data. If the transmission mode is set to be symmetrical between uplink and downlink, the transmission rate of uplink and downlink is 432.6 kb/s. Under normal circumstances, the transmission distance is 10m (30FEET), and the maximum can reach 100m, which is automatically adjusted.
2 HCI overview
The Host Controller Interface (HCI) is the interface between software and hardware in the Bluetooth protocol. It provides a unified command interface for calling hardware such as baseband, link management, status and control registers. When communicating between Bluetooth devices, the protocol software entities above the HCI run on the host, while the functions below the HCI are completed by the Bluetooth device, and the two interact through a transport layer that is transparent to both ends.
As shown in Figure 1, the Bluetooth standard defines the machine controller interface (HCI) as follows: HCI provides a command interface for calling and accessing the baseband controller and link controller, as well as hardware status and control registers. This interface provides a unified method of accessing Bluetooth baseband functionality. There are several intermediate layers that are not closely related to the Bluetooth protocol between the HCI software on the host side and the HCI firmware on the Bluetooth hardware. We call it the machine controller transport layer, which provides transparent data transmission.
HCI consists of two parts, the software implementing the command interface and the physical hardware used to connect the Bluetooth subsystem and the host. The purpose of HCI software is to make the hardware that makes up the interface appear transparent to the higher-level software of the system.
The Bluetooth software architecture includes two types of components. The data-related components are responsible for the transmission of data through the link. Control-related components are responsible for link control and management. Figure 2 shows the HCI software structure and the relationship with the Bluetooth host interface hardware.
3 HCI flow control
The flow control is between the host and the host controller to prevent the ACL data to be transmitted to the unanswered remote device from overflowing the host controller’s data buffer, which is managed by the host.
The host is initialized by issuing the Read_Buffer_Size command. The return parameter of this command can determine the maximum length of the HCI ACL and SCO packets (excluding the header) sent by the host to the host controller. The other two return parameters indicate the number of HCI ACL and SCO data packets that the host controller can buffer for pending transmission. When there is only one connection to the other device or the device is in loopback mode, the master controller uses the completed data packet event to control the flow of data from the master. The event grouping includes a list of link handles and the number of HCI packets completed on the corresponding connection since the last event; completion refers to sending, flushing, or looping back to the host. According to the return parameter of this event and the return parameter of the read buffer size command, the master controller can perform flow control. Whenever the host sends an ACL or SCO packet, the host should record that the remaining space in the corresponding link buffer of the master controller is reduced by one packet. When the host receives the completion packet number event, the host knows how much buffer space there is. After being released, the host can count the number of packets that can be received by the present host controller. When the main controller has data, it must periodically send the completion packet number event to the host until it reports to the host that all packets are sent or cleared, and the sending interval is defined by each manufacturer. Note that if SCO flow control fails, the completed packet event number cannot be reported in the SCO link handle.
Corresponding to each link handle, the data must be sent to the main controller in the HCI packet in the order in which they were generated by the host. The host controller also sends these data to the air in the same order. When received, the server must also send it to its host in order, which means that the order of data on the same connection handle does not change since it was generated.
In some cases, the flow control from the main controller to the host is necessary. Generally, the Set_Host_Controller To_Host_Flow_Control command is used to switch the flow control in this direction. The flow control method in this direction is similar to the method described above. Initially, the host issues the Host_Buffer_Size command to inform the host controller of the maximum length of ACL and SCO packets sent to the host and the number of ACL and SCO packets that can be stored in the host buffer. The host uses the host Host_Number_Of_Completed_ Packets command similar to the master controller’s number of completed packets event. The host completes packet number command is a special command that does not require command flow control and can be sent at any time when there is a connection or in local loopback mode, which allows both directions The flow control works the same, and the normal command flow is not interrupted.
When the host receives the unchaining completion event, it can be determined that all the data sent to the main controller on the connection handle is cleared, and the corresponding data buffer is released. The main controller does not need to use the completion packet number event to inform the host. If the flow control from the main controller to the host is also adopted, the main controller assumes that the host also clears all the data on the connection handle after receiving the event after sending the disconnection completion event, and the host does not need to This is communicated to the host controller with the host complete packet number command.
4 HCI commands and events
The host controls the Bluetooth network interface through a series of commands provided by the HCI driver. In addition to these commands, the Bluetooth standard also defines a level of events generated by the HCI firmware in the Bluetooth network interface to indicate a state change of the interface.
HCI commands and events are transmitted through the HCI transport interface hardware along with data from connectionless and isochronous connections. The way in which these data are multiplexed is determined for the interface. Figure 3 shows its operation.
HCI provides a unified method to access Bluetooth hardware. HCI link commands provide the ability for the host to control link layer connections with other Bluetooth devices, typically these commands cause the link manager to exchange link manager protocol commands with the remote device. HCI policy commands are used to influence the behavior of a local or remote link manager. These commands provide a method for the host to influence how the link manager manages the piconet. The host controller and baseband commands, information commands and status commands are used by the host to access different registers on the host controller.
HCI commands take a certain amount of time to complete, so the processing results of these commands are returned to the host in the form of events. For example, for most HCI commands, the host controller generates a command completion event after completion, and this event includes the return parameters of the completed command. In order to enable the host to have the ability to detect errors in the HCI transport layer, we judge whether it times out between the host sending a command and receiving the response from the host controller. Due to differences in different HCI transport layers, it is recommended to use one second as the default value of this timer.
HCI transmits data, commands and events by means of packets, and all communication between the host and the main controller is carried out in the form of packets. The return parameters, including each command, are transmitted through specific event packets. HCI has three types of packets: data, command and event, in which data packets are bidirectional, command packets can only be sent from the host to the main controller, and event packets are always sent from the main controller to the host. Most command packets sent by the host will trigger the host controller to generate corresponding event packets in response. The format of the package is shown in Figure 4.
(1) The command package is divided into six types:
● link control commands; ● link policy and mode commands; ● Host control and baseband commands; ● information commands; ● Status command; ● Test commands.
(2) Event packages can be divided into three types:
● Common events, including Command Complete and Command Status; ● test events; ● Events that occur when an error occurs, such as Flush Occured and Data Buffer Overflow.
(3) Data packets can be divided into ACL and SCO packets.
5 HCI module structure
The HCI module completes the protocol function, encapsulates the HCI command and the data of the upper-layer protocol, and processes the lower-layer event according to the protocol.
The HCI command event processing module completes the encapsulation of the command and the analysis of the event. After receiving the call command request from the upper-layer protocol or application, the module completes the encapsulation of the command packet, and then calls the sending function to transmit the data to the data transceiver module. When the receiving function receives the HCI event, it calls the event processing function of the HCI command event processing module, and after processing, transmits the response to the upper-layer protocol or application according to the nature of the event.
The HCI data processing module completes the encapsulation processing of ACL and SCO data, but does not parse and process the payload. The transceiver function mainly completes the communication with the data transceiver module, and calls the command event processing module or the data processing module to process the received data according to the type of the data.
6 HCI transport layer
The transport layer of HCI defines how three types of data are transmitted between the Bluetooth network interface and the Bluetooth host. The HCI transport layer defines how each type of data is encapsulated and multiplexed through the interface hardware. At present, the Bluetooth specification defines three HCI transport layers: UART transport layer; RS232 transport layer; USB transport layer. The HCI transmission layer is specifically described below by taking the RS232 transmission layer as an example.
The goal of the HCI RS232 transport layer is to use Bluetooth HCI over the physical RS232 interface between the Bluetooth host and the Bluetooth host controller. Four HCI packets can be sent out through the RS232 transport layer, but the main controller interface cannot distinguish the four HCI types. An 8-bit group indicator must be added before the group to distinguish the group type. 0x01 represents an instruction packet, 0x02 represents an ACL data packet, 0x03 represents an SCO data packet, 0x04 represents an event packet, 0x05 represents an error message packet, and 0x06 represents a negotiation packet. Error message packets are used to report errors to the sender; while negotiation packets are used to negotiate communication settings and protocols. The baud rate, parity type, stop bits and protocol mode should be negotiated between the host controller and the host before sending any bytes on the RS232 link. An 8-bit sequence number is incremented by 1 each time more than one HCI packet is sent, unless an erroneous packet is retransmitted.
The synchronization mechanism can choose RTS/CTS or delimiter. When RTS/CTS cannot be used, frames with 16-bit CRC and delimiter 0x7e with COBS will be used as a means of error detection and resynchronization. The 16-bit CRC shall be appended to the end of the packet, before the closing delimiter 0x7e. The start delimiter 0x7e is followed by the packet type indication segment. COBS is an improvement of PPP, it will incur less than 5% overhead regardless of data mode. A simple error correction scheme is used here, and the sender will only retransmit the packets that contain errors.
[Introduction]If in 2020, GaN (gallium nitride) has become popular in the mobile phone fast charging market by virtue of its penetration into the mobile phone fast charging market, and has become a “net celebrity” in the wide bandgap (WBG) semiconductor industry. By 2021, the market will The focus turns to another wide-bandgap semiconductor “new favorite” SiC (silicon carbide). This is because Tesla, a cutting-edge new energy vehicle company, to a traditional old car company, has invariably announced that it will be pure The plan to upgrade the electric drive system of electric vehicles from silicon-based inverters to SiC inverters has triggered a global “core battle” for SiC devices.
As we all know, in the field of Power electronics, the performance of Si devices is getting closer and closer to the theoretical limit, and the “bonus” that the follow-up can provide to users is becoming more and more limited. The iterative upgrade of “quality” has become the general trend of the entire industry.
Figure 1: Comparison of Si, SiC and GaN material properties
(Source: ON Semiconductor)
As can be seen from Figure 1, as a member of the wide band gap semiconductor material family, the band gap of SiC is as high as 3.26 eV, which is 3 times that of Si material (1.12 eV), which means that the electrons of SiC material are removed from the valence band. The energy required to move to the conduction band is about 3 times that of Si material, so devices made with SiC can withstand higher breakdown voltages with 10 times the dielectric breakdown field strength of Si. And higher breakdown field strength is beneficial to reduce the “thickness” of the device under the same rated voltage, thereby reducing the on-resistance of the device and improving its current carrying capacity – these characteristics are exactly the dream of many power Electronic devices. of.
At the same time, the electron saturation speed of SiC is 2 times higher than that of Si material. The higher the value is, the faster the switching speed of power devices can be done, which makes the driving power required for high-frequency operation under high voltage smaller, and the corresponding energy Losses are also lower. And from the system point of view, the high-frequency switching circuit allows the use of smaller peripheral devices, making the entire power electronic system design more compact, which can be described as killing two birds with one stone.
Furthermore, the thermal conductivity of SiC is 3 times that of Si. At a given power consumption, higher thermal conductivity means lower temperature rise, which makes SiC devices have better thermal performance and can support more high power density. Compared to other materials, SiC can achieve a junction temperature of 600°C, so using bonding and packaging techniques to ensure high operating temperatures of 150°C to 200°C in commercial SiC devices is clearly a skill.
Figure 2: Advantages of SiC technology in power electronics applications
(Source: ON Semiconductor)
It is precisely because of these characteristics and advantages that SiC has become an ideal “candidate” for power electronic systems to achieve higher power density, higher switching speed, lower power loss, higher operating temperature, and smaller system size and cost.
Although currently due to the particularity of the manufacturing process, improving the yield and productivity of SiC devices is still a big challenge, and the cost of SiC devices is relatively high, but from a system point of view, after replacing Si devices, it is possible to achieve Smaller package size and cost, improve the overall energy efficiency of the system, so the overall cost assessment is still very cost-effective. For example, some people have estimated that the use of SiC power devices can reduce the power consumption of the vehicle by 5%-10%. Although the cost of the inverter module will increase, comprehensively speaking, the battery cost, Cooling costs, as well as space usage costs, will be significantly reduced, resulting in a total vehicle cost savings of about $2,000. It is not difficult to understand why the new energy vehicle circle is so enthusiastic about SiC.
Ideal power switching device
The purpose of the power electronic system is to efficiently control and transmit high-voltage and high-current high-power energy. Therefore, in people’s minds, an ideal power electronic switching device should meet three requirements: a sufficiently high withstand voltage, the lowest possible on-resistance, and a higher switching speed.
To this end, people use Si material to create two power switching devices: MOSFET and IGBT. These two devices have their own characteristics, but due to the material properties of Si, they are still far from the goal of “ideal” power switching devices.
Specifically, silicon-based MOSFETs have the advantage of higher switching speeds (up to several hundreds of kHz), but larger on-resistance and larger recovery losses. And due to the characteristics of Si material, its withstand voltage is generally limited to less than 1,000V, so it is difficult to be competent in high-voltage and high-power applications.
Compared with MOSFET, IGBT can achieve higher withstand voltage and lower on-resistance, so it has more advantages in high-power applications; however, due to the minority carrier accumulation effect, IGBT reverse recovery is slow, making it limited in high-speed switching applications.
Therefore, silicon-based MOSFETs are generally preferred for low-voltage, high-frequency switching applications, while IGBTs are more suitable for higher-voltage, higher-current, low-frequency applications. Compared with the above-mentioned Si devices, SiC MOSFET can combine many advantages such as high withstand voltage, high frequency, low power consumption, etc., coupled with outstanding high-temperature operating characteristics, it can be said that it is an “ideal” device in terms of performance. ” of the power switching device.
Figure 3: Suitable application range for different power switching devices
(Source: ON Semiconductor)
Figure 4 compares three different types of power switching devices under 1,200V withstand voltage. It can be seen intuitively that the on-resistance of SiC MOSFET devices is only 1/100 of that of SiMOSFET (SiC) and 1/1 of that of Si IGBT. 3 to 1/5, while lower switching losses can be achieved. Therefore, in the long run, in the field of power electronics from 650V to 1,700V, especially 1,200V and above – such as new energy vehicles, solar energy and power systems, etc. – SiC MOSFETs have unparalleled advantages.
Figure 4: Comparison of SiC MOSFETs and silicon-based power switching devices
(Source: ON Semiconductor)
Building reliable SiC MOSFETs
It is precisely because SiC MOSFET is an ideal choice for a wide range of power switching applications that in recent years, power semiconductor manufacturers have also taken it as an important market fulcrum in the future, and have continued to invest in creating commercially available SiC MOSFET devices. Among them, the M3S 1200V Si MOSFET launched by ON Semiconductor is a very good one.
Figure 5: 1200V SiC MOSFET based on M3S technology
(Source: ON Semiconductor)
In addition to the inherent advantages of SiC MOSFET devices mentioned above, M3S 1200V SiC MOSFETs have three distinct features:
First, based on M3S technology, the device achieves an on-resistance of 22mΩ and features low Eon and Eoff losses. According to data provided by ON Semiconductor, it can reduce power loss by 20% compared with competing products in hard switching applications.
Second, due to the TO247-4LD package, the device can achieve lower common-source inductance, which allows this SiC MOSFET to support higher slew rates in system design, effectively controlling switching while operating at high frequency loss.
Again, this SiC MOSFET has good drive compatibility. Be aware that SiC MOSFETs have lower drift layer resistance than Si devices, but their lower carrier mobility results in higher channel resistance, so SiC MOSFETs require higher gate-source voltages than Si devices (usually 18V to 20V) before entering saturation mode to get the lowest possible on-resistance and prevent accidental switching. That is to say, in general, SiC MOSFETs are incompatible with 10V standard Si MOSFET gate drivers and 15V IGBT gate drivers, and special drive devices are often required. The 1200V MOSFET with M3S planar technology can be used with 18V dedicated gate driver for excellent performance or with 15V IGBT gate driver and is reliable with negative gate voltage drive and turn-off spikes. Work.
In short, ON Semiconductor’s M3S 1200V SiC MOSFET not only maximizes the advantages of SiC materials, but also optimizes reliability and ease of use, effectively accelerating the application of SiC MOSFETs in energy storage, Solar inverters, new energy vehicles and other fields.
Improve the design ecology of SiC
Of course, as a latecomer, SiC wants to complete the replacement of Si power devices that have been developed for decades, not overnight, nor can it be accomplished by relying on a few devices with excellent performance, but a complete technology ecosystem to support. As a major manufacturer in the field of power semiconductors, ON Semiconductor is well aware of this, and has been actively improving its product layout around the SiC state circle.
On the one hand, it can be seen from Figure 6 that ON Semiconductor has formed a rich SiC device product portfolio, covering different withstand voltage levels and different package types; including SiC diodes, SiC MOSFETs, and SiC modules; in SiC modules, both Hybrid modules including IGBT + SiC diodes, as well as full SiC modules – this can meet the needs of different customer power electronics upgrade iterations at different stages.
Figure 6: ON Semiconductor’s SiC Product Line Portfolio
(Source: ON Semiconductor)
On the other hand, in addition to SiC devices themselves, ON Semiconductor can also provide technical resources supporting SiC devices, such as high-end gate driver ICs specially designed for SiC FETs, and SPICE physical models, which can facilitate developers to apply SiC devices. Circuits are simulated to simplify the design process and save development costs. All these efforts are making the iterative process of upgrading SiC technology smoother and faster.
According to IHS Markit’s analysis data, the market size of SiC power devices in 2020 is about 600 million US dollars, and by 2027 this figure will reach 10 billion US dollars. Faced with such a fast-growing market, how should we plan ahead and make adequate preparations? From the SiC device product portfolio to the supporting design ecology, where should more complete technical resources be obtained to support the next upgrade journey of power electronics technology?
How to take this step of SiC technology upgrade, the answer is as follows, come and see——
Related technical resources
M3S 1200V SiC MOSFET, learn more >>
ON Semiconductor Wide Bandgap SiC Technology Resource Center, learn more>>