Sony AS-DT1 LiDAR

The Sony AS-DT1 LiDAR is a multipoint distance sensor that connects to PX4 over a UART/serial port.

PX4 configures the sensor for binary output and publishes the measurements to the obstacle_distance uORB topic.

Supported Modes

The driver supports the AS-DT1 distance measurement range modes listed below.

Mode	Maximum Measurement Distance	Minimum Frame Interval	Distance Measurement Points
30MSTD	30 m	33.33 ms	576
30M15F	30 m	66.66 ms	576
30M30F	30 m	33.33 ms	288
20M	20 m	33.33 ms	576
40M	40 m	66.66 ms	576

The mode is selected using SENS_ASDT1_MODE.

Collision Prevention Output

The driver publishes the AS-DT1 data to the obstacle_distance uORB topic used by Collision Prevention. The message uses 72 bins at 5 degree increments around the vehicle.

The AS-DT1 horizontal field of view is about 35 degrees. The driver maps the sensor's horizontal band into the matching obstacle_distance bins and leaves uncovered directions as no-data. SENS_ASDT1_ROT sets the yaw offset of this field of view relative to vehicle forward.

Hardware Setup

The sensor can be connected to any unused serial port (UART), such as TELEM2, TELEM3, or GPS2.

The AS-DT1 uses the 8-pin JST-GH connector for external power and UART. Connect the sensor TX/RX pins to the flight controller UART and share ground between the sensor power supply and flight controller.

AS-DT1 8-pin Connector	Function	Connect To
Pin 1	GND	External power ground and flight controller serial GND
Pin 2	VCC	External 12 V to 24 V power supply
Pin 5	UART TX	Flight controller serial RX
Pin 6	UART RX	Flight controller serial TX

The ground from AS-DT1 pin 1 must be common to both the external power supply and the flight controller serial port. For example, splice or split the AS-DT1 ground wire so it connects to the power supply negative terminal and to the flight controller UART GND pin.

Do not connect the AS-DT1 UART pins directly to RS-232 or RS-422 interfaces. The AS-DT1 UART RX input is 5 V tolerant, and the sensor should be powered from the external 12 V to 24 V supply described in the Sony hardware documentation.

Firmware Setup

The sony_asdt1 driver must be included in the PX4 firmware for the target board. If the Sony AS-DT1 parameters are not available, add the following line to the target board's default.px4board configuration, or enable the driver using boardconfig:

CONFIG_DRIVERS_DISTANCE_SENSOR_SONY_ASDT1=y

Then rebuild and flash the firmware.

Parameter Setup

Use the Sony application to set the sensor to Measurement (UART) mode before connecting it to PX4.

The driver uses the following parameters:

Parameter	Description
SENS_ASDT1_CFG	Selects the serial port and enables driver autostart on boot.
SENS_ASDT1_MODE	Selects the AS-DT1 measurement range mode. The driver configures the sensor mode and publishes matching obstacle_distance metadata.
SENS_ASDT1_ROT	Sets the sensor yaw offset, in degrees, relative to vehicle forward. This is published as obstacle_distance.angle_offset; positive values are clockwise.

SENS_ASDT1_MODE and SENS_ASDT1_ROT may not appear until SENS_ASDT1_CFG is enabled and the flight controller has rebooted once.

Reboot the flight controller, or restart the driver manually, after changing these parameters.

Configure the serial port on which the sensor will run using SENS_ASDT1_CFG. There is no need to set the baud rate for the port, as this is configured by the driver.

Set SENS_ASDT1_MODE to the required measurement mode and reboot the flight controller.

If the sensor is mounted with a yaw offset from vehicle forward, set SENS_ASDT1_ROT to the offset in degrees. Positive values are clockwise.

Testing

You can check the driver state in the QGroundControl MAVLink Console:

sony_asdt1 status

You can observe the published measurements with:

listener obstacle_distance

To print the sensor's saved configuration without starting measurements, run:

sony_asdt1 start -d /dev/ttyS2 -s

Replace /dev/ttyS2 with the serial device for your board and port.

Further Information

• Modules Reference: Distance Sensor (Driver): sony_asdt1