H-Flow (Optical Flow and Distance Sensor Module)

The Holybro H-Flow is a compact sensor module that combines optical flow measurement, distance sensing, and a 6-axis IMU in a single device. It integrates the PixArt PAA3905E1 optical flow sensor, the Broadcom AFBR-S50LV85D distance sensor, and the InvenSense ICM-42688-P IMU. Thanks to this integrated design, installation is particularly simple. An onboard infrared LED also ensures reliable operation in low-light conditions.

For connection to the flight control system, the H-Flow is equipped with a Pixhawk-standard 4-pin CAN connector and can be connected directly to Pixhawk-compatible controllers via the CAN bus. Communication is handled via the DroneCAN protocol, which enables stable, fast, and robust data transmission between the sensor and the flight controller.

Technical Specifications

• PixArt PAA3905E1 Optical Flow Sensor
  • Tracking under low-light conditions (> 5 lux)
  • Effective field of view up to 42°
  • Wide operating range from 80 mm up to 30 m
  • Maximum angular velocity up to 7.4 rad/s
  • Integrated 40 mW IR LED with a 120° viewing angle for improved low-light performance
• Broadcom AFBR-S50LV85D Time-of-Flight Distance Sensor
  • Integrated 850 nm laser light source
  • Field of view (FoV): 12.4° × 6.2° with 32 pixels
  • Typical sensing range up to 30 m
  • Operation under ambient light up to 200,000 lux
  • Reliable performance on nearly all surface types
  • Transmitter beam of 2° × 2° to illuminate between 1 and 3 pixels
• InvenSense ICM-42688-P 6-axis IMU
• MCU: STM32F412CEU6
• Interface: Pixhawk-standard CAN connector (4-pin JST-GH)
• Form Factor: Compact design
• CAN Termination: Software-controlled
• Weight: 15.2 g (3.5 g without casing)

Scope of delivery 

• 1× H-Flow
• 4-pin GH cable
• 2× M2.5 screws
• 2× M2.5 nylon locking hex nuts