TIDUE59A May   2018  – September 2020

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5. 1System Description
    1. 1.1 Key System Specifications
  6. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 CC3220
      2. 2.3.2 CC2640R2F
      3. 2.3.3 DRV8837
    4. 2.4 System Design Theory
      1. 2.4.1 CC3220S to CC2640R2F Interface
      2. 2.4.2 CC3220S to DRV8837 Interface
      3. 2.4.3 Software Architecture
      4. 2.4.4 Network Connection Management
      5. 2.4.5 Provisioning
        1. 2.4.5.1 AP Provisioning and SmartConfig™
        2. 2.4.5.2 Wi-Fi Provisioning Over BLE
      6. 2.4.6 Sending and Receiving Messages Through Cloud
        1. 2.4.6.1 Message Queue Telemetry Transport Protocol
        2. 2.4.6.2 MQTT Client Implementation
      7. 2.4.7 Over-the-Air Updates
        1. 2.4.7.1 HyperText Transfer Protocol
      8. 2.4.8 Security Enablers
        1. 2.4.8.1 Secure Boot
        2. 2.4.8.2 Secure Sockets
          1. 2.4.8.2.1 Hardware Accelerators
          2. 2.4.8.2.2 Simple Network Time Protocol
        3. 2.4.8.3 File System Security
          1. 2.4.8.3.1 Failsafe Files and Bundle Protection
      9. 2.4.9 Low-Power Consumption
  7. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
        1. 3.1.1.1 CC3220S LaunchPad™ Development Kit
        2. 3.1.1.2 CC2640R2F LaunchPad™ Development Kit
        3. 3.1.1.3 Sensor BoosterPack™ Connections (BMI160)
        4. 3.1.1.4 DRV8837EVM Modifications and Connections
        5. 3.1.1.5 Assembling EVMs
      2. 3.1.2 Software
        1. 3.1.2.1 Getting Started With Software
          1. 3.1.2.1.1 Build simple_np Application and Flash CC2640R2F
          2. 3.1.2.1.2 Use Premade UniFlash ImageCreator Project
          3. 3.1.2.1.3 Importing Project Source Files Into CCS
        2. 3.1.2.2 User Files
        3. 3.1.2.3 Run Wi-Fi® Doorlock Demo
          1. 3.1.2.3.1 Connect CC3220 to Network
          2. 3.1.2.3.2 Networking Functions
            1. 3.1.2.3.2.1 Get Current Date and Time (SNTP)
            2. 3.1.2.3.2.2 Send and Receive Messages (MQTT)
            3. 3.1.2.3.2.3 Perform Software Update Using Dropbox (OTA Update)
    2. 3.2 Testing and Results
      1. 3.2.1 Pass or Fail Tests
      2. 3.2.2 Power Measurements
      3. 3.2.3 Test Setup
        1. 3.2.3.1 CC3220S
        2. 3.2.3.2 CC2640R2F
        3. 3.2.3.3 DRV8837
      4. 3.2.4 Test Results
      5. 3.2.5 Battery Life Estimate
  8. 4Design Files
  9. 5Software Files
  10. 6Related Documentation
    1. 6.1 Trademarks
  11. 7Terminology
  12. 8About the Author
  13. 9Revision History

1 System Description

This reference design demonstrates how to create a battery-powered, electronic smart lock with integrated Wi-Fi. The design demonstrates how the SimpleLink Wi-Fi CC3220S wireless MCU (SoC) can be used as the main system controller and network processor to create a highly integrated design. The TIDC-01005 reference design combines the CC3220S with a DRV8837, 1.8-A, low-voltage, brushed DC motor driver, to form the core of a Wi-Fi enabled electronic smart lock design. The design also features the SimpleLink Bluetooth® low energy CC2640R2F wireless MCU to demonstrate Wi-Fi provisioning over BLE. The design leverages LaunchPad™ Development kits and the DRV8837EVM, which makes it easy to reproduce and evaluate. The software for the TIDC-01005 is based on the SimpleLink SDK to enable maximum portability within the SimpleLink Platform.

The TIDC-01005 can be connected to a Wi-Fi access point (AP) using either the SimpleLink SDK Explorer or SimpleLink Wi-Fi Starter Pro mobile application. When connected to the AP, the design establishes a secure connection to the cloud, which lets the user remotely control and monitor the state of the lock system. Integrating Wi-Fi into the lock eliminates the need for the user to have a wireless bridge to connect the system to their Wi-Fi network and IoT ecosystem. In addition to demonstrating remote access to the lock system, the TIDC-01005 design also demonstrates how the CC3220S can be used to implement a fast OTA software update for the lock, while demonstrating the use of multiple CC3220S security enablers.

The two main design considerations for the TIDC-01005 were low-power capability and integrated security features. The ability to support a Wi-Fi connection with very low-power is critical for Wi-Fi-enabled electronic smart locks, because they are often battery powered. Additionally, many security features must be supported by an electronic smart-lock design for it to be robust and function as a reliable component in an access control system. The TIDC-01005 demonstrates how to achieve very low-current consumption with the CC3220S when creating a system that is always connected to the network. The design also demonstrates the following key security features:

  • Secure boot of application code
  • AP provisioning using WPA2 authentication and HTTPS
  • Wi-Fi provisioning over BLE, with secure simple pairing
  • Secure socket connections to the cloud for messaging and OTA updates
  • OTA update using multiple security enablers:
    • File integrity check
    • Signature verification
    • Failsafe files
    • Bundle protection

Many of the features demonstrated in the TIDC-01005 application are based on the networking application libraries available in the SimpleLink SDK, including SNTP, MQTT, and HTTP. These protocols and the features they are used to implement in the software are applicable to many other building automation systems that integrate Wi-Fi connectivity. In particular, multiple aspects of the TIDC-01005 design may also apply to door keypad and reader designs.