Designing a Passive Lidar Detector Device
4 days ago
- #iPhone
- #Hardware
- #LiDAR
- Samy Kamkar's DEF CON 32 talk on laser microphones inspired the idea of detecting iPhone LiDAR activation.
- iPhone 15 Pro's TrueDepth LiDAR system operates at 60Hz with a 940nm VCSEL dot grid lattice, detectable via cameras without IR filters.
- The LiDAR system activates when apps like the default camera app are opened, allowing detection before an image is taken.
- Similar detection could identify when an iPhone is on the lock screen or when Pixel 5+ devices with off-screens are nearby.
- Research involved studying patents and existing work to understand the LiDAR's 60Hz, 940nm infrared signal characteristics.
- Hardware development tested various IR detection methods, with 940nm peak photodiodes providing the clearest signals.
- The device needs to discern 60Hz signals from noise, requiring high-speed processing with components like 10MHz op-amps or Schmitt triggers.
- A SAMD21 microcontroller was chosen for its balance of processing power and energy efficiency.
- Multiple discrete IR sensors are necessary to differentiate LiDAR signals from other sources like displays.
- Future posts will cover firmware development and demonstration of the device's capabilities.