Marvelmind for Non-GPS navigation

This article explains how a MarvelMind system can be as a short-range substitute for a GPS allowing position control modes like Auto and Guided. See the user manual for more details on the system.

Note

Support was added in Copter-3.6 and Rover-3.3. This wiki page is a work-in-progress.

image courtesy of marvelmind.com

Required Hardware

• Marvelmind Starter Set

Marvelmind Settings

• Ensure the Marvelmind is firmware version 5.77 (or higher) and enable the ‘Raw Distances Data’ in the Dashboard
• Set the stationary beacon with the lowest address as the origin in your dashboard.
• The height of every stationary beacon, from the ground, must be set on the dashboard.
• The hedge should be set to output Marvelmind Protocol at baud rate of 115200.

Connecting to a flight controller

• Ensure that Copter-3.6 (or higher) or Rover-3.3 is loaded onto the flight controller and connect with a Ground Station (i.e. Mission Planner).
• Enable the EKF3 as described here
• Set EK3_ALT_SOURCE to 3 (means using Marvelmind for altitude)
• Set EK3_GPS_TYPE to 3 (means Inhibit GPS use)
• Set BCN_TYPE to 2 (means using Marvelmind system)
• Set BCN_LATITUDE, BCN_LONGITUDE and BCN_ALT to match your actual location. Getting these values exactly correct is not particularly important although getting it close is required in order for the compass’s declination to be correctly looked up from the small database held within ArduPilot.
• Set BCN_ORIENT_YAW to the heading from the origin beacon to the 2nd beacon. One way to capture this value is to stand at the origin holding the vehicle so that it’s nose points towards the second beacon. Read the vehicle’s heading from the HUD and enter this value into BCN_ORIENT_YAW
• Set GPS_TYPE to 0 to disable the GPS
• Set ARMING_CHECK to -9 to disable the GPS arming check
• Set SERIAL1_BAUD to 115 to set telemetry1’s baud rate to 115200 (if using Telem2 set SERIAL2_BAUD instead)
• Set SERIAL1_PROTOCOL to 13 to enable receiving data from the marvelmind (If using Telem2 set SERIAL2_PROTOCOL instead)
• Set BRD_SER1_RTSCTS to 0 to ensure telem1 does not use flow control (If using Telem2 set BRD_SER2_RTSCTS instead, not required if using Serial4/5)

Ground Testing

• Connect the Flight Controller to a ground station
• Click on ‘freeze map’ on the dashboard
• After about 1 minute the vehicle’s position should jump to the latitude, longitude you input during the configuration step (above)
• Check that the vehicle’s position is relatively stable (i.e. moving around less than one meter)
• Walk the vehicle around between the beacons and ensure that its position on the map updates correctly

DataFlash logging

The distance to the beacons can be found in the dataflash log’s BCN message’s D0, D1, D2, D3 fields.