SLAAEF6 September   2023 MSPM0L1105 , MSPM0L1106 , MSPM0L1306 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 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
  5. 2Hardware and Schematic
    1. 2.1 MSPM0L1306
    2. 2.2 MSPM0 PIR Boosterpack
      1. 2.2.1 Schematic
  6. 3Software
    1. 3.1 Software Architecture
    2. 3.2 Software Flow Chart
    3. 3.3 Data Processing
      1. 3.3.1 Digital Signal Conditioning
      2. 3.3.2 Low-Pass Filter for Temperature Drift
      3. 3.3.3 Spikes and Noise
      4. 3.3.4 Motion Detection Function
  7. 4Results
    1. 4.1 Power Profile and Current Consumption
    2. 4.2 Detection Performance
      1. 4.2.1 Distance: 5 meters (16.4 ft)
      2. 4.2.2 Distance: 9 meters (29.5 ft)
      3. 4.2.3 Distance: 10 meters (32.8 ft)
  8. 5Summary
  9. 6References

Abstract

Motion detection is valuable in many battery powered building automation applications, from basic security sensors to fully interactive camera systems. These systems rely on accurate, low power motion detection to maximize battery life by keeping powerful processors and wireless radios shut down when not needed. This design provides a low power, high-performance, and very cost competitive motion detection solution using an analog passive infrared (PIR) motion sensor and the MSPM0L1306. The MSPM0L1306 has integrated operational amplifiers (OPAs) and digital to analog convertors (DACs). The OPAs can provide the PIR sensor’s entire signal chain, integrated inside the MSPM0. The OPAs are software configurable, allowing the signal chain to be easily adjusted for higher sensitivity and range, digital feedback loops, and optimized for low-power performance. This application note addresses ultra-low power, high-performance PIR design theory and test results using the MSPM0L1306.

Demo code mentioned in this document can be found in the MSPM0 SDK.