Goodix BLE Wiki

• Development Guide
  • Goodix BLE Knowledge Base Usage Wizard
    • 1. Knowledge Categorization
    • 2. User Wizard
  • Goodix BLE Product Development Wizard
    • 1. Information List
    • 2. Access to Chip Product Information
    • 3. Get the chip SDK development kit
    • 4. Getting the Chip and Board
      • 4.1 Enterprise users
      • 4.2 Individual and Community Users
    • 5. Access to Chip Development Tools
      • 5.1 Standard Development Software
      • 5.2 Goodix Development Tools Collection
    • 6. Obtaining Chip Development Documentation
      • 6.1 GR551x Documents
      • 6.2 GR5525 Documents
      • 6.3 GR5526 Documents
      • 6.4 GR533x Documents
    • 7. Obtaining technical support
    • 7.1 Product Technical Solutions
      • 7.2 Eco-Technology Integration
    • 8. Technical Services
• Application Notes
  • System
    • Low power consumption
      • 1. Basic Function Introduction
      • 2. Application Notes
    • Memory application notes
      • 1. Introduction to Basic Functions
        • 1.1 Memory Resources Overview
        • 1.2 Memory Layout
        • 1.3 Typical Application Resource Usage and User Available Resources
      • 2. Application Notes
        • 2.1 Link Script Application Guide (ARMCC Scatter File as an example, other link scripts are similar)
        • 2.2 Calculate the RAM and firmware size used by the program (ARMCC compiler, other compilers can refer to the following method)
          • 2.2.1 GR551x (SDK V2.0.1, user unmodified link script)
          • 2.2.2 GR533x (SDK V1.0.5, user unmodified link script)
    • Introduction to Fault Trace module
      • 1. Fault Trace module introduction
      • 2. Precautions for using Fault Trace Module
    • APP LOG Module Application Notes
      • 1. APP LOG module basic function introduction
      • 2. Notes on APP LOG Module Usage
    • Suggestions for the use of Heap
    • Encryption and Signature
      • 1. Security Solution
      • 2. Tool-side workflow
      • 3. Device-side workflow
      • 4. Tool side (GProgrammer) encryption and signature operation
      • 5. GProgrammer Sign-Only Operation
      • 6. Uncheck Encrypt, only Sign will sign the target Firmware.
    • Introduction to FDS
      • 1. Introduction to FDS
      • 2. NVDS application notes
      • 3. APP FDS Application Notes
      • 4. APP LOG Store Application Notes
  • Peripherals
    • I/O
      • I/O Application Notes
        • 1. I/O Basic Functions Introduction
        • 2. I/O Application Notes
    • ADC
      • ADC Application Notes
        • 1. Introduction to ADC Basic Functions
          • 1.1 ADC Function Overview
          • 1.2 Single-Ended Mode Measurement
          • 1.3 Differential Mode Measurement
          • 1.4 How to Select External Reference Voltage for Measurement
          • 1.5 How to Measure Chip Supply Voltage
          • 1.6 How to Measure Internal Chip Temperature
          • 1.7 How to Perform Multi-Channel Measurement
        • 2. Typical ADC Applications
          • 2.1 How to Evaluate Whether the Measurement Range Meets the Requirements
          • 2.2 How to Evaluate Whether the Resolution Meets the Requirements
          • 2.3 How to Improve Measurement Accuracy
          • 2.4 Calibration Method for Selecting Special External Reference Voltage
      • ADC Sampling Rate Test
        • 1. ADC Sampling Clock
        • 2. Testing Sampling Rate
          • 2.1 Required Settings
          • 2.2 Main Test Code
          • 2.3 Testing Results
    • DMA
      • DMA
        • 1. Introduction to Basic Functions
        • 2. Application Notes
    • I2C
      • I2C Application Notes
        • 1. Introduction to GR5xx I2C Basic Functions
        • 2. Typical I2C Applications
          • 2.1 How to Set Slave Address
          • 2.2 I2C Circuit Pull Up Resistor Configuration Considerations
          • 2.3 I2C Working Mode Recommendations
    • I2S
    • SPI and QSPI
      • Topic for SPI and QSPI
        • 01. SPI-QSPI Protocol Special Topic (1) - Introduction to Basic Protocol Features
          • 1. SPI Protocol
            • 1.1 Pin Signals
            • 1.2 Roles
            • 1.3 Clock Frequency
            • 1.4 Clock Modes
            • 1.5 Timing Phase
            • 1.6 SPI Protocol Derived Timing
          • QSPI Protocol
            • 2.1 Overview
            • 2.2 Pin Signals
            • 2.3 Timing Phase
            • 2.4 Instruction Addressing Mode
            • 2.5 QPI Modes
            • 2.6 SIOO Modes
            • 2.7 Efficiency Calculation
        • 02. SPI-QSPI Protocol Special Topic (2) - Fundamentals of Building GR55xx (Q)SPI High-Speed Transmission Interface
          • 1. Basic Application Background Supplement
            • 1.1 System Master and Slave
            • 1.2 Synchronous and Asynchronous Access
          • 2. Data Transmission Behavior
            • 2.1 Writing Data from CPU to Screen via QSPI
            • 2.2 Writing Data via DMA Directly to Screen through QSPI
            • 2.3 Reservoir Problem in Transmission (Producer & Consumer Problem)
        • 03. SPI-QSPI Protocol Special Topic (3) - GR552x Chip’s DMA and QSPI Module Features
          • 1. Typical DMA Features
            • 1.1 Typical DMA Applications
              • 1.1.1 DMA Base Data Transmission
              • 1.1.2 DMA Chain Data Transmission
              • 1.1.3 DMA Scatter Transmission
              • 1.1.4 DMA Gather Transmission
              • 1.1.5 DMA Scatter and Gather Transmission
            • 1.2 Features of DMA Transmission Channel
          • 2. Typical QSPI Features
            • 2.1 QSPI Working Modes
            • 2.2 QSPI Data Endian
              • 2.2.1 Data Endian in Write Operations
              • 2.2.2 Data Endian in Read Operations 2.2.2
              • 2.2.3 Read Rule for Static Data Endian in Memory Mapping Mode
              • 2.2.4 Read Rule for Dynamic Data Endian in Memory Mapped Mode 2.2.4
        • 04. SPI-QSPI Protocol Special Topic (4) - Color Formats and Common Exceptions
          • 1. Screen Color Format
            • 1.1 Common Color Code Formats
            • 1.2 Color Code Format Storage and Usage
          • 2. Analysis of Possible Causes of Out-of-Order Execution
            • 2.1 Inconsistent Read/Write Width of External Flash Leading to Reversal
            • 2.2 Abnormal Byte Order Configuration in Memory Mapped Read of External Flash
            • 2.3 Out-of-Order Due to Unaligned Address in DMA Access
          • 3. Common Display Issues
      • SPI Application Notes
        • 1. Introduction to Basic Functions
        • 2. Application Notes
      • QSPI Application Notes
        • 1. Basic Function Introduction
        • 2. Application Notes
        • 3. Typical Application Scenarios
          • 3.1 GR5526 supports the use of external flash as firmware cache for OTA upgrade.
    • Timer
      • Application Note for Timer and Dual Timer
        • 1. Introduction to Timer and Dual Timer Basic Functions
        • 2. Application Notes for Timer and Dual Timer
      • APP RTC Application Note
        • 1. Introduction to RTC Basic Functions
        • 2. APP RTC Application Note for GR5xx
      • Typical WDT Applications
        • 1. Introduction to GR5xx WDT Basic Functions
        • 2. Typical GR5xx WDT Applications
      • GR5xx Timers
        • 1. Overview of GR5xx Timers
        • 2. Clock configuration of GR5xx slow clock timers
        • 3. RTOS tick implementation of each chip
    • UART
      • UART Application Notes
        • 1. Introduction to UART Basic Functions
        • 2. UART Application Notes
    • USB
      • USB Introduction
        • 1. Introduction to USB
        • 2. Typical USB Applications
    • X-QSPI
      • X-QSPI Application Note
        • 1. Introduction to Basic Functions
        • 2. Application Notes
    • GPU
      • GPU Application Notes
        • 1. Introduction to Basic Functions
          • 1.1 Main Features of GPU
          • 1.2 GPU Usage Key Points
            • 1.2.1 Frame Buffer
            • 1.2.2 Memory Allocation and Usage
            • 1.2.3 Reference Recommendations
        • 2. Application Notes
      • OSPI PSRAM Application Notes
        • 1. PSRAM Address Space Layout and Management
        • 2. Initialization and Usage of PSRAM
        • 3. PSRAM Working Mode
        • 4. PSRAM Sleep Strategy
          • 4.1 Hibernation Strategy in Bare Metal Environment
          • 4.2 Sleep Strategy in RTOS Environment
      • DC Application Note
        • 1. Introduction to Basic Functions
        • 2. Application Notes
  • BLE
    • BLE Basicals
      • BLE Broadcasting
        • 1. Introduction to the basic functions of BLE broadcasting
        • 2. Broadcast Application Notes
        • 3. FAQ
          • 3.1 Can the broadcast data be modified all the time?
          • 3.2 How do I turn on two broadcasts at the same time?
          • 3.3 How to enable multi broadcast?
          • 3.4 Is dynamic modification of the broadcast interval supported?
          • 3.5 How to set the broadcast power?
          • 3.6 How to set broadcast for HID device to make system bluetooth display device name?
          • 3.7 How to set the broadcast packet can use 31 Bytes instead of 28 Bytes?
      • BLE Profile
        • 1. Introduction to the basic concept of BLE Profile
        • 2. BLE Profile Application Notes
        • 3. FAQ
          • 3.1 I didn’t add any Service in the sample project, but I can see two Services after connecting to the phone, where do these two Services come from? What are they used for?
          • 3.2 Is there a limit to the number of BLE services that can be created by the chip? What is the maximum number of services that can be supported to be created?
          • 3.3 Execute ble_gattc_prf_read and the callback status is 0x0005, what does it mean?
          • 3.4 Is there any example of file transfer in SDK and what is the suggested method to realize this function?
          • 3.5 Regarding the static void samples_cccd_set_cb(uint8_t conn_idx, uint16_t handle, uint16_t cccd_value) function, when connecting it will always report a cccd_value = SAMPLES_EVT_TX_ NOTIFICATION_DISABLED event when connecting. What is the meaning of this value?
      • BLE Master
        • 1. Introduction to the basic functions of BLE Master scanning
        • 2. BLE Master Scanning Application Notes
        • 3. FAQ
          • 3.1 Do I need to stop scanning when I initiate a connection?
          • 3.2 Does it support to connect to multiple devices at the same time?
          • 3.3 Does it support to set scanning power?
          • 3.4 How to use the scanning whitelist function?
          • 3.5 Can Master act as Server and Slave act as Client?
      • BLE Multi Slave
        • 1. Introduction to GR5xx Multi Slave Basic Concepts
        • 2. GR5xx Multi-slave Application Notes
        • 3. FAQ
          • 3.1 BLE slave devices originally support multiple connections, so what is the difference between multiple connections and multiple slaves? What are the specific application scenarios of dual or multiple slaves?
          • 3.2 In the actual application of dual-slave project, the broadcast of each link is independent, if there are frequent modification of the broadcast address of the application scenarios, how should it be realized?
          • 3.3 The same phone can connect to both slaves normally, but why does each slave find services that are not as expected after the connection is established?
          • 3.4 The dual slaves are connected normally, and the service discovery is normal, but when I send a message from the device to the cell phone, why can’t the cell phone receive it?
      • BLE Multi Role
        • 1. Introduction to GR5xx Multi-Master-Multi-Slave Concepts
        • 2. GR5xx Multi-Master Multi-Slave Application Notes
        • 3. FAQ
          • 3.1 What is the maximum number of connections that GR5xx can support when designing a master-slave application scenario?
          • 3.2 In ble_app_uart_multilink master-slave example, how to differentiate the slaves? How do I change the slave device settings for the default connection?
          • 3.3 Common problem analysis of open broadcast or scanning failure in BLE multi-service scenarios.
          • 3.4 In a master-multi-slave scenario, there is no problem with master-slave communication of one pair of one device, but when master-slave communication of one pair of ten devices, commands are sent to the slaves one by one via conn_idx, and the slaves can’t receive the data in case of a large amount of data, which is because of Bluetooth transmission scheduling problem?
      • BLE Multi-Connect
        • 1. GR5xx BLE Multi-connections Basic Function Introduction
        • 2. GR5xx Multi-connections Application Notes
        • 3. FAQ
          • 3.1 How many connections can the GR5xx chip communicate stably?
          • 3.2 How to optimize the stability of multiple connections?
          • 3.3 Does broadcasting need to be re-enabled after the connection is established in the “one-slave-many-hosts” scenario?
      • BLE Security
        • 1. Introduction to basic BLE SM concepts
        • 2. GR5xx BLE SM Application Notes
        • 3. FAQ
          • 3.1 There is a problem with BLE pairing, what should I do to solve it?
          • 3.2 BLE Bluetooth connection, how to connect directly without prompting pairing request?
          • 3.3 Which part of the code in the routine ble_app_hids_keyboard knows the Bluetooth pairing code? How to enter the Bluetooth pairing code? The key pairing routine?
          • 3.4 Every time the device connects, the pairing box pops up, and it is reasonable to say that only the first pairing will pop up the box, but not the subsequent ones. How to solve this problem?
          • 3.5 How to prevent GR5xx Bluetooth peripheral from being captured? How is the communication data encrypted?
          • 3.6 How to get the MAC address of the opposite device (e.g. cell phone) after pairing?
          • 3.7 After device bonding, the iOS device address will change, how to make sure the device with changed address can connect?
      • BLE Data Rates
        • 1. Theoretical Transmission Rate
        • 2. Factors affecting BLE data transfer rate
        • 3. FAQ
          • 3.1 I want to modify the PDU parameters in cell phone, but I didn’t find the API interface, how can I do it?
          • 3.2 Why is the throughput rate of Apple phone low during throughput rate test?
    • BLE Application
      • Conflict handling between BLE and XIP-Flash
        • 1. How to avoid conflicts between BLE and Flash operations
        • 2. So when is each Sector Delay needed and when is it not?
      • BLE exception code
        • 1. BLE disconnected reason introduction and analysis
        • 2. Common causes of disconnection
          • 2.1 0x98 Timeout Disconnection
          • 2.2 0xB8 Immediate Instruction Misses
          • 2.3 0xB2 Response Timeout
          • 2.4 0xCE Failure to establish connection
          • 2.5 0xA3 Remote Active Disconnection
          • 2.6 0xA6 Local active disconnection
          • 2.7 0xCD Crypto related disconnection
          • 2.8 Other Disconnects
      • BLE HID Applications
        • 1. Introduction to BLE HID
        • 2. BLE HID Application Notes
        • 3. FAQ
          • 3.1 After the HID device is successfully connected to the iOS device, the device does not respond, what is the reason?
          • 3.2 After the HID device is successfully paired with the host side, there is no response from the device side to send data, what is the reason?
          • 3.3 The product application needs to integrate multiple Keyboard and Mouse functions, how to realize it?
      • BLE Mesh
        • 1. Introduction to BLE Mesh Basic Concepts
        • 2. BLE Mesh Application Notes
        • 3. FAQ
          • 3.1 Where can I find the introduction of Mesh principle and protocol?
          • 3.2 Are BLE legacy features and BLE Mesh already included in the BLE stack library file? Or is BLE Mesh a separate protocol stack library file? Is there some documentation and information related to BLE Mesh development?
          • 3.3 How many operating modes does GR533x Mesh low power support? What is the power consumption of different operating modes?Does GR533x support specific micro-operating system?
          • 3.4 What is the maximum number of BLE nodes that can be connected to the mesh? Is there any kind of mesh topology, or is it just a star structure?
          • 3.5 Is there a Goodix Mesh SDK application development brief?
    • DFU Application
      • DFU Application Introduction
        • 1. GR5xx DFU Introduction
        • 2. DFU Program Selection
        • 3. Flash Layout Division
          • 3.1 Upgrade Mode
          • 3.2 App Bootloader Description
          • 3.3 Introduction to Important Details
          • 3.4 Third Party DFU Adaptation
        • 4. FAQ
          • 4.1 How to enable Fast DFU mode?
          • 4.2 Where is the Fast DFU rate limitation and how much rate can be reached?
          • 4.3 How is DFU low-power under RTOS?
  • Tools
    • GRPLT Tool
      • 1. GRPLT basic function introduction
      • 2. GRPLT Application Notes
    • GRPLT Lite Tool
      • 1. GRPLT Lite basic function introduction
      • 2. GRPLT Lite Application Notes
    • IAR Application Notes
      • 1. Basic Introduction
      • 2. Using GR5xx SDK in IAR
        • 2.1 Generating an IAR project based on a Keil project
        • 2.2 Configuration Debugging and Downloading
    • Ellisys User Guide
      • 1. Important Note
      • 2. Preface
      • 3. About the hardware
      • 4. Getting Started
        • 4.1 Main Interface
        • 4.2 Quick Start
        • 4.3 Packet Catching Configuration
        • 4.4 Only lip packet filtering
  • Hardware
    • ESD Application Notes
      • 1. GR5xx Series Chip ESD Performance Introduction
      • 2. ESD Application Notes for GR5xx Series Chipsets
    • RF Application Notes
      • 1. Introduction to GR5xx RF
      • 2. GR5xx RF Application Notes
    • Minimal System Application Notes
      • 1. Introduction to the GR5xx Minimum System
      • 2. GR5xx Minimum System Application Notes
  • Application
• Tech Case
  • Smart Wearable Technology Solution
    • Wearable (Watch) Solutions Technical Wizard
      • 1. Suggestions on the use of series chips in wearable products
        • 1.1 GR551x Series
          • 1.1.1 Key performance parameters
          • 1.1.2 Material number
        • 1.2 GR5526 Series
          • 1.2.1 Key performance parameters
          • 1.2.2 Material number
        • 1.3 GR5525 Series
          • 1.3.1 Key performance parameters
          • 1.3.2 Material number
        • 1.4 Selection reference
          • 1.4.1 Parameter comparison
          • 1.4.2 GR5525 vs GR551x
          • 1.4.3 GR5526 vs GR5525
          • 1.4.4 General reference for type selection
      • 2. Reference to the scheme
    • GR5526 (1)-User Guide for watch reference scheme
      • 1. GR5526 Wear (Watch) Ref.
        • 1.1 Example Project
        • 1.2 Drive reference
        • 1.3 LVGL GUI Framework Instructions
      • 2. Instructions for use of the migration
        • 2.1 typical peripheral adaptation
          • 2.1.1 Adaptation of screen driver
          • 2.1.2 Touch adaptation
          • 2.1.3 Data Nor Flash Adaptation
        • 2.2 Lvgl related
          • 2.2.1 Resolution Configuration
          • 2.2.2 Color configuration
          • 2.2.3 Frame Buffer
          • 2.2.4 Definition of frame format
        • 2.3 User Task Description
    • GR5526 (2)-Generate image resources for Lvgl specification
      • 1. Tool introduction
      • 2. Generate a picture resource
        • 2.1 Prepare picture resource data
        • 2.2 Organize image directory format
        • 2.3 Perform resource generation
      • 3. Use of build resource files
        • 3.1 Burn the.bin file
        • 3.Adjust the source code descriptor file according to the actual situation of the project
        • 3.3 Embed the source code.c/.h file into the Lvgl project
        • 3.4 Download address of related tools
    • GR5526 (3)-Generate font resources for Lvgl specification
      • 1. Tool introduction
      • 2. Use of tools
        • 2.1 Prepare Tools and Font Resources
        • 2.2. Generate bitmap source code files according to application requirements
        • 2.Embed the generated.c source code into the lvgl application project
      • 3. Other considerations
        • 3.1 Appendix
    • GR5526 (4)-Merge Lvgl font bitmaps into bin
      • 1. Use background and description
      • 2. Lvgl format bitmap data to bin films
        • 2.1How to generate fonts for Lvgl
        • 2.2 Generates font resources that conform to the Lvgl specification for GPU adaptation
        • 2.Method of generating font bitmap bin file
        • 2.4 Script Tool Download
    • GR5526 (5)- Build a reference application for Lvgl
      • 1. Foreword
      • 2.Download the sample project for a taste
      • 3. Write the first LVGL interface
        • 3.1 Find the GUI entry point
        • 3.Write a LVGL interface
      • 4. LVGL basic concepts
        • 4.1 LVGL object
        • 4.2 LVGL style
      • 5. Revamping the first LVGL interface
    • GR5526 (6)-Power Debug Reference for Watch Demo
      • 1. Refer to the engineering description
      • 2. Low Power Mode Background
      • 3. Low Power Debugging Based on Watch Demo
        • 3.1 Principle
        • 3.2 Test environment setup
        • 3.3 The main tasks of the Watch Demo project related to hibernation
        • 3.4 Working mode design of Watch Demo
        • 3.5 Sleep Mode Debugging
          • 3.5.1 Principles
          • 3.5.2 General conditions
          • 3.5.3 Method for determining whether the peripheral is in working state
          • 3.5.4 Examples
        • 3.6 Current waveform of each operation mode
          • 3.6.1 Current waveform of working mode switching
          • 3.6.2 Current Waveform with BLE Broadcast Sleep
    • GR5526 (7)-Debugging rendering exceptions using savebin
      • 1. Background
      • 2. Analyze Frame Buffer
        • 2.1 Get Frame Buffer Parameters
        • 2.2 Capture frame buffer data in debugging state
        • 2.3 Check buffer exception
    • GR5526 (8)-Graphical FAQ and Solution Reference
      • 1. Lvgl display class problem
        • 1.1 Lvgl When rotating an image, the image appears to be foldover at some rotation angles.
    • GR5526 (9)-Display Controller Driver Configuration Reference
      • 1. Display controller
        • 1.1Initialization function parameter
        • 1.2 Frame data sending interface parameters
      • 2. Other DC Interface Timing Diagram
        • 2.1 app_graphics_dc_spi_send
        • 2.2 app_graphics_dc_dspi_send_cmd_in_3wire_1lane
        • 2.3 app_graphics_dc_dspi_send_cmd_data_in_3wire_1lane
        • 2.4 app_graphics_dc_dspi_send_cmd_data_in_4wire_2lane
        • 2.5 app_graphics_dc_dspi_send_cmd_datas_in_4wire_2lane
  • Find My Technology Solution
    • Apple Find My Technical Solution
      • 1. Introduction to Apple FMNA
      • 2. Overall process of FMNA project of third-party brand manufacturer
      • 3. Apple Search Network Features and Principles
      • 4. Apple Find My Solution Based on Goodix GR551x & GR533x Series
      • 5. GR5xxx Apple Find My Development Case Experience Sharing
      • 6. Frequently Asked Questions (FAQ)
• FAQ
  • FAQ for System
    • FAQ for Low Power
      • 1. Why does the system still not go to sleep when I configure Sleep mode?
      • 2. Does the system not go to sleep after a UART call app_uart_receive_async?
      • 3. J-Link connection failed, SK board cannot download firmware, why?
      • 4. The wake-up time is not set in the program, and the Bluetooth is not turned on. After directly entering the sleep mode, why does it wake up automatically every 30 seconds?
      • 5. J-Log is no longer output after a part of Log is output in the Link RTT Viewer. Why?
    • FAQ for Memory
      • 1. How does Keil limit the compiled firmware size?
      • 2. How to fix a variable at a specified address?
    • FAQ for Fault Trace
      • 1. How can I tell if my program is a HardFault?
      • 2. Why does my program get HardFault?
      • 3. Can I analyze the above without using the Cortex Backtrace component?
      • 4. If you don’t use the Fault Trace module, can you analyze HardFault?
      • 5. What’s going on when the PC points to an inexplicable place?
      • 6. What if I can’t read the data on the stack?
    • FAQ for LOG Module
      • 1. What is the maximum baud rate of UART for LOG?
      • 2. What should I do if I can’t see the output on the computer when I use the serial port to type LOG?
      • 3. How to type LOG with SEGGER RTT?
      • 4. Why does RTT print the log for a period of time and then stop printing, and the system is stuck?
      • 5. What should I do if I can’t see the LOG after J-Link RTT Viewer is connected?
      • 6. How to export the stored LOG?
      • 7. When using GRToolbox to export the storage LOG, what should I do if the LOG is incomplete?
      • 8. When using GRToolbox to export logs, I find that only the most recent logs are available, and I can’t get earlier logs. What should I do?
  • FAQ for Peripherals
    • I/O
      • FAQ for I/O
        • 1. How to deal with the problem of high sleep power consumption due to IO leakage (how to properly configure and detect IOs before sleep)?
        • 2. How to deal with IO interrupt loss?
        • 3. Does IO have push-pull output mode?
        • 4. What is the reason for the large frequency error when outputting a square wave using IO flip-flop?
    • ADC
      • FQA for ADC
        • 1. Calling the asynchronous acquisition interface keeps failing to generate a completion interrupt
        • 2. Some of the internal reference voltage stalls are captured with large errors in the results
        • 3. High sampling rate with large error in the result.
        • 4. Slow Asynchronous Acquisition Interface
        • 5. Synchronous capture interface fails to generate data
    • DMA
      • FAQ for DMA
        • 1. DMA transfers use the concept of beat, what is a beat?
        • 2. Can the same DMA channel of the same DMA instance be configured for use by different peripherals at the same time?
    • I2C
      • FAQ for I2C
        • 1. During I2C transmission, the SDA is abnormal and is forced down all the time by the slave and cannot be recovered, what is the reason?
        • 2. During I2C transfer, SCL is abnormal and stuck at low level.
    • I2S
    • QSPI
      • FAQ for QSPI
        • 1. What is the maximum frequency supported by QSPI?
        • 2. QSPI Operation Mode Introduction
        • 3. What is the reason for data end-sequence exception when using Memory Map mode to access external Flash?
        • 4. Using traditional API interface (non-Memory Map mode) to read external Flash, the data does not match the desired data endian order.
        • 5. How to support QSPI module to use Memory Map mode to access Flash larger than 16 MB 4-byte address?
        • 6. Accessing Flash using the QSPI sample project from the SDK fails, why?
        • 7. What are the reference programs for the QSPI peripheral?
    • SPI
      • FAQ for SPI
        • 1. What is the maximum frequency supported by SPI?
        • 2. What is software chip select, what is hardware chip select, and what is the difference in usage?
        • 3. A callback error event APP_SPI_EVT_ERROR occurs when SPI receives data, how should I handle it?
    • Timer
      • FAQ for GPTimer
        • 1. What is the difference between app_tim.c and app_timer.c? Which timers are low power timers? Which ones are not?
        • 2. Using Timer/Dual Timer timing, test the timing accuracy by flipping the IO in interrupt, and found the error is relatively large, what is the reason?
        • 3. Using Timer/Dual Timer timing, test the timing accuracy by flipping the IO in the interrupt, and found that the error of the first cycle is very large, and the later cycles meet the requirement, what is the reason?
      • FAQ for RTC
        • 1. What are the reasons for the large RTC timing errors?
        • 2. How to get the system runtime according to RTC?
        • 3. The RTC does not work, or call app_rtc_get_time(&time) and find that the time obtained remains the same, what is the reason?
      • FAQ for WDT
        • 1. What are the reasons why the watchdog does not work (or does not feed the dog for a predetermined period of time, but does not generate a reset)?
        • 2. The watchdog reset time is not correct, what is the reason?
    • UART
      • FAQ for UART
        • 1. GR5xx chip serial port no data output, print garbage, data reception abnormal, what may be the reason?
        • 2. GR5xx chip serial port easily trigger APP_UART_EVT_ERROR interrupt, what is the reason?
        • 3. How to configure GR5xx chip serial module?
    • USB
    • X-QSPI
  • FAQ for BLE
    • During BLE Connection，How to get remote RSSI？
  • FAQ for Tools
    • Build Tools
      • Usage of J-Link RTT
        • 1. How to turn on the RTT function in the sample project
        • 2. The Skill of Obtaining the Compiler Address of _ SEGGER _ RTT;
        • 3. When J-Link RTT prints the log, the log will not be printed after working for a while
      • Building Goodix BLE Development Environment Based on VSCode
      • FAQ for Ellisys
        • 1. How to judge the signal quality of air interface packets? How to improve the quality of captured packets?
        • 2. When I capture packets, I can only capture a small portion of the packet, and the packet capture device and software are running normally, but there are no more packets after that, what’s wrong?
        • 3. I can only catch classic broadcasts, but not extended broadcasts, what’s wrong?
        • 4. The program is running and I can see the broadcast packets on the packet grabber, but I can’t scan the device through the cell phone tool or the probability of connecting to the device is very low after I found the device, what’s the problem?
        • 5. How does a packet grabber pull signals from a program while grabbing empty packets?
        • 6. Why some encrypted packets can be decrypted while others cannot?
        • 7. What is the problem that the packet grabber is running very slow?
        • 8. After a long time of packet capturing, the packet capturing software is very laggy and fills up our system disk, what should I do?
        • 9. How to check the current broadcast period or connection period by empty packets, so as to check that our code is configured as expected?
        • 10. I want to make sure that my broadcast data is set up correctly, or I want to make sure that the connection data is sent out, where should I look at the sent out air port data?
    • Graphics Tools
      • FAQ for graphics tools
        • 1. How do I generate an image resource that conforms to the LVGL specification for GPU?
        • 2. How do I generate font resources that conform to the LVGL specification for GPU adaptation?
    • Product Line Tools
      • FAQ for GRPLT
        • 1. What is the principle of crystal calibration?
        • 2. What is the RSSI test method?
        • 3. Where is the.bin file for the new version of the online tool (after V1.5.0.0.4)?
        • 4. When do we need secondary development?
        • 5. How is custom encryption different from Goodix encryption?
        • 6. Report 0x1A badness (test firmware operation failure), what is the possible reason?
        • 7. The online tool reports 0xFC fault (test firmware download fails). What is the possible reason?
        • 8. 0x10 badness (abnormal crystal calibration) is reported. What is the possible reason?
        • 9. Report 0x 12 error (abnormal burning), what is the possible reason?
        • 10. After starting the GRPLT, when connecting the DUT, clicking “Start” does not respond. What is the possible reason?
        • 11. After opening GRPLT, 16 small windows are not displayed. What may be the reason?
      • FAQ for GRPLT Lite
        • 1. What is the principle of crystal calibration?
        • 2. What is the RSSI test method?
        • 3. How is custom encryption different from Goodix encryption?
        • 4. Test Firmware failed to run (0x39), what could be the cause?
        • 5. Test firmware download failed (0x37, 0x38), what could be the cause?
        • 6. Crystal calibration exception (0x3A, 0x3B, 0x3C), what could be the cause?
        • 7. How to solve the time-consuming problem of port self-starting test?
  • FAQ for Hardware
    • FAQ for ESD
      • 1. Why is the system-level ESD performance degraded when IO pins are near the edge of the PCB?
    • FAQ for RF
      • 1. Can the PI circuit for RF be simplified or removed?
      • 2. How does GR551x extend PA or FEM to improve transmission distance?
      • 3. What are the reasons for the low conducted sensitivity and transmit power of the GR5xx?
      • 4. Why are there two first matching capacitors in the GR5331/GR5330 series?
      • 5. Why are there small pF capacitors on the GR533x series VBAT _ RF and GPIO0/1?
      • 6. What about the poor modulation characteristics of GR533x series?
      • 7. What is the reason why the GR533x SK board power or sensitivity cannot be matched to the GR533x different PCB boards using reference design matching parameters?
    • FAQ for Minimum System
      • 1. DC-DC 2.2 μH Inductor Selection Requirements?
      • 2. Why does the peripheral interrupt need to access the IO of the AON domain?
      • 3. Can the 32 K external crystal be omitted?
      • 4. How to simplify BOM when GR533x is powered only in SYSLDO mode?
      • 5. Does a 32m, 32.768K crystal require additional external load capacitance?
      • 6. Can the 2.2 μH inductor of the DCDC be replaced with another inductor value?
      • 7. Can the output capacitance of DCDC be increased?
      • 8. What should we pay attention to in DCDC Layout?
      • 9. What does RF Layout need to pay attention to?
      • 10. What should I pay attention to when measuring high-speed signal waveforms such as QSPI?
      • 11. Why can’t some active probes detect the signal transformation of RTC clock signal?
      • 12. What are the 32m, 32.768K crystal PCB Layout requirements?
      • 13. What are the PCB Layout requirements for high-speed signals such as QSPI?
      • 14. Why is the power consumption during sleep high?
      • 15. Are there any precautions when using an external PA?
      • 16. What are the requirements for the LDO power chip when the GR5xx is powered by an LDO?
  • FAQ for Business
    • BLE Product Certification Guidelines
      • 1. BQB Certification
      • 2. SRRC Certification
      • 3. CE Certification
      • 4. FCC Certification
      • 5. Other Certifications
      • 6. Description of RSE Certification
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