Laser Interface

Overview

Laser Interface
The Avionics Anonymous Laser Altimeter Interface is a tiny interface for several common laser rangefinders that allows connection to Pixhawk and other similar autopilots via UAVCAN - A nice robust interface, no sketchy long-distance I2C wiring and no hogged serial ports! These lasers are great for use as laser altimeters which help with nice auto landings. Comes fully assembled, ready to use!

Currently supported Lasers

At time of writing the following rangefinders are supported:
  • Lightware SF02
  • Lightware SF10/a
  • Lightware SF10/b
  • Lightware SF10/c
  • Lightware SF11/b
  • Lightware SF11/c
  • Lightware SF(LW)20/b
  • Lightware SF(LW)20/c
  • Lightware SF30/D
Coming soon:
  • Lidar Lite
  • Others - contact us with your needs!

What makes it special?

  • Robust UAVCAN interface is compatible with most Pixhawks and similar autopilots and makes it safe to install your laser far away from the autopilot, wherever is convenient!
  • Onboard power filtering for connected laser
  • Mount with screws through mounting ears or snip them off and foam tape it straight to your laser
  • Update firmware via CAN interface

Specifications

  • Weight: 3.2 grams
  • Size: 1.25in x 0.75in x 0.25in
  • Power: 4.0V to 5.5V, XXmA

Required Accessories

  • ​CAN Harness - connects between the autopilot and a CAN node and between each CAN node on the bus
  • ​CAN Terminator - connects to the last device on the CAN bus

Where to Buy

User Guide

Wiring

The rangefinder (laser) is connected to the AvAnon Laser Interface board, which is connected to one of the CAN ports on your autopilot. The wiring is per the pinout below, or the necessary cables can be purchased to connect to your system right out of the box:
  • ​CAN Harness - connects between the autopilot and a CAN node and between each CAN node on the bus
  • ​CAN Terminator - connects to the last device on the CAN bus
The interface board provides a filtered power output for the laser, but does not provide its own regulation. Therefore, the laser must be compatible with whatever voltage is supplied to the Laser Interface.

Pinouts

CAN Connector
Pin
Name
Description
1
POWER_IN
Power Supply. 4.0-5.5V supported, but must also be compatible with connected laser.
2
CAN_H
CAN high
3
CAN_L
CAN low
4
GND
Signal/power ground.
Laser Connector
Pin
Name
Description
1
POWER_OUT
Filtered power at the supply voltage.
2
TX/SCL
TX for serial mode, Clock for I2C mode
3
RX/SDA
RX for serial mode, Data for I2C mode
4
GND
Signal/power ground.
Connection to Lightware SF0x/SF1x/SF30 Lasers
Connection to Lightware LW20

Configuration

Autopilot Configuration

PX4
Several autopilot parameters must be set using QGC or similar:
  • UAVCAN must be enabled by setting UAVCAN_ENABLE non zero. Set this to 1 for basic functionality or 2 to allow the device's UAVCAN parameters to be accessed via QGC.
  • The minimum and maximum valid range for the laser must be set in the parameters UAVCAN_RNG_MIN and UAVCAN_RNG_MAX. These should be set according to the rangefinder manufacturer's datasheet.

Rangefinder Configuration

Certain parameters must be configured in your rangefinder per the manufacturer's guidance
Rangefinder Model
Notes
Lightware SF02
Must be set to 115200 baud
Lightware SF10/a
Must be set to 115200 baud
Lightware SF10/b
Must be set to 115200 baud
Lightware SF10/c
Must be set to 115200 baud
Lightware SF11/c
Must be set to 115200 baud
Lightware SF11/b
Must be set to 115200 baud
Lightware SF(LW)20/b
Must be set to 115200 baud. Returns default distance.
Lightware SF11/b
Must be set to 115200 baud. Returns default distance.
Lightware SF30/D
Must be set to 115200 baud. Returns default distance.

Node Configuration

The Laser Interface node has a number of parameters accessible via the UAVCAN interface. These may be set following the steps outlined here​
Parameters
Parameter Name
Description
Default Value
Allowable Values
node_id
Node ID for this device
103
1-125
rangefinder_hw
Rangefinder type specifier - see list below
5 (or as ordered)
1-10 (see below)
first_return
Use "first" or "last" return range, if supported by rangefinder
0
0 = last return, 1 = first return
Rangefinder Hardware Options
Rangefinder Model
rangefinder_hw Value
Wiring Type
Lightware SF02
1
Serial
Lightware SF10/a
2
Serial
Lightware SF10/b
3
Serial
Lightware SF10/c
4
Serial
Lightware SF11/c
5
Serial
Lightware SF11/b
6
Serial
Lightware SF(LW)20/b
7
Serial
Lightware SF11/b
8
Serial
Lightware SF30/D
10
Serial

Firmware

laserInterface-1.2.90f8dfae.bin
271KB
Binary
Firmware v1.2

Release Notes

v1.2

  • Improve SF0X timeout recovery

v1.0

  • Initial Release
Last modified 1yr ago