Holybro MS4525DO Digital Airspeed Sensor

The Holybro MS4525DO is a digital differential-pressure airspeed sensor for fixed-wing and VTOL aircraft on Pixhawk-class flight controllers running ArduPilot or PX4. The reading is digitised on the sensor board and sent over I2C, so long cable runs out to a wing or nose do not add the noise and offset drift of analogue airspeed sensors.

Key features

• MS4525DO-DS5AI001DP sensor with a 1 psi range, roughly up to 100 m/s (360 km/h).

• 0.84 Pa resolution, with data delivered at 14 bits from a 24-bit delta-sigma ADC.

• Onboard temperature measurement lets the autopilot convert indicated to true airspeed using the flight controller's static pressure sensor.

• Mounted away from the flight controller, so its temperature reading sits closer to the outside air than sensors placed near warm electronics.

• M3 / 6-32 mounting holes; supplied with a pitot tube, rubber tubing and a JST-GH 4-pin cable.

Specifications

• Sensor: MS4525DO-DS5AI001DP

• Range: 1 psi (burst 10 psi)

• Resolution: 0.84 Pa, 14-bit output

• Interface: I2C, address 0x28

• Input voltage: 4.75–5.25 V

• Current draw: about 3 mA

• Operating temperature: -25 to 105 °C

• Dimensions: 17 x 23 x 13 mm

• Weight: 4.1 g (sensor board)

To enable it, set ARSPD_TYPE to 1 (MS4525) in ArduPilot, or enable SENS_EN_MS4525DO in PX4, then calibrate on the ground before the first flight.