SLAAE30 July   2021 MSP430FR2355

 

  1.   Abstract
  2.   Trademarks
  3. 1PIR Design Description
    1. 1.1 PIR Sensor
    2. 1.2 PIR Signal Chain
      1. 1.2.1 Traditional Motion Detection Signal Chain Design
      2. 1.2.2 Capacitor-Free Signal Chain Design
  4. 2Software
    1. 2.1 Software Architecture
    2. 2.2 Software Flow Chart
    3. 2.3 Power Profile
    4. 2.4 Data Processing
      1. 2.4.1 Digital Signal Conditioning
      2. 2.4.2 Low-Pass Filter for Temperature Drift
      3. 2.4.3 Spikes and Noise
      4. 2.4.4 Motion Detection Function
  5. 3Hardware and Schematic
    1. 3.1 MSP430FR2355
    2. 3.2 Schematic
  6. 4Results
    1. 4.1 Distance: 15 ft (4.5 m)
    2. 4.2 Distance: 22.5 ft (6.9 m)
    3. 4.3 Distance: 36.5 ft (11.1 m)
  7. 5Summary
  8. 6References

2.2 Software Flow Chart

Figure 2-2 shows a flow chart of the software's overall behavior. The demo software wakes up and performs this full loop 20 times a second. The loops takes approximately 250 µs - 300 µs. The other 99% of the time, the analog is shut down and the MSP430 is sleeping in low power mode 3. This flow chart is explained somewhat further in the power profile section.

GUID-2E750552-AA4A-4D05-9E8C-9DA5B35103C2-low.png Figure 2-2 Software Flow Chart