TIDUEZ4 May   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 SimpleLink MCU
        1. 2.2.1.1 CC3235MODS
        2. 2.2.1.2 CC1352R LaunchPad
          1. 2.2.1.2.1 CC1352R
      2. 2.2.2 Power
        1. 2.2.2.1 TPS63802
        2. 2.2.2.2 TPS63900
        3. 2.2.2.3 TPS62825
        4. 2.2.2.4 TPS7A03
        5. 2.2.2.5 TPS7A20
        6. 2.2.2.6 TPS62840
        7. 2.2.2.7 TPS22919
        8. 2.2.2.8 LM66100
      3. 2.2.3 Peripherals
        1. 2.2.3.1 OPT3004
        2. 2.2.3.2 DRV8837C
        3. 2.2.3.3 TPA2011
        4. 2.2.3.4 TLV61048
      4. 2.2.4 OmniVision Video Encoder OA7000
      5. 2.2.5 OmniVision Image Sensor SP2329
      6. 2.2.6 YTOT Lens Module
    3. 2.3 Design Considerations
      1. 2.3.1  Input Power: Battery and USB
      2. 2.3.2  Power Requirements
      3. 2.3.3  Camera Wake-up and Day or Night Sensing
        1. 2.3.3.1 PIR and MSP430 Based Motion Detection Design for Low Cost and High Performance
      4. 2.3.4  Battery Gauging
      5. 2.3.5  IR LED Illumination
      6. 2.3.6  IR Cut Filter
      7. 2.3.7  Audio
      8. 2.3.8  System Operation
      9. 2.3.9  Wi-Fi and Host Subsystem
      10. 2.3.10 Firmware Control
        1. 2.3.10.1 Application Flow
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware
    2. 3.2 Software
    3. 3.3 Setup
      1. 3.3.1 Configuration Steps for Video over Wi-Fi
      2. 3.3.2 (Optional) Flash OA7000 With Latest Firmware or Stream Video Over USB
      3. 3.3.3 Audio Streaming
      4. 3.3.4 LPSTK-CC1352R Configuration Steps for Camera Module
    4. 3.4 Test Results
      1. 3.4.1 Power Supply Rails and Current Consumption
      2. 3.4.2 Battery Life Calculations
      3. 3.4.3 Video Streaming
      4. 3.4.4 IR LED Drive
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 Bill of Materials
    2. 4.2 Software
    3. 4.3 Support Resources
    4. 4.4 References
    5. 4.5 Trademarks
  10. 5About the Author

2.3.6 IR Cut Filter

A brushed DC motor driver DRV8837C drives the IR cut filter integrated in the lens module. DRV8837C supports up to 1 A maximum current and protection for short-circuit, shoot-through, under-voltage, and over-temperature. Figure 2-24 shows the IR cut filter driver circuit.

GUID-20210422-CA0I-ZDL0-WC6H-MPZSDTL2GPC1-low.gif Figure 2-24 IR cut Filter Driver Circuit in the Design

nSLEEP or enable function can be set by the host processor CC3235MODS. Logic level drive and duty cycle of PWM for IN1 and IN2 pins can also be programmed, as Table 2-4 shows, by the host processor to control the direction or open or close position for the IR cut filter.

Table 2-4 DRV8837C Device Logic
nSLEEP IN1 IN2 OUT1 OUT2 FUNCTION
(DC MOTOR)
0 X X Z Z Coast
1 0 0 Z Z Coast
1 0 1 L H Reverse
1 1 0 H L Forward
1 1 1 L L Brake