Cube Flight Controller Bootloader Update

Owned by Conor McCaffrey (Unlicensed)
Last updated: Sept 18, 2020
2 min read

Background

A spontaneous issue can occur that would cause the Cube flight controller to fail to completely boot. In the error state the IO co-processor would boot. However, the primary (FMU) processor would not boot. The problem was a spontaneous occurrence. Some vehicles exhibited the issue more than others, but no correlation could be found that would indicate a cause. Replacing components, including the Cube itself, would have varying results.

The problem was ultimately traced to an issue with pin definitions occurring at boot time. A processor pin that was designated as a soft reset pin was left undefined to avoid possible uncommanded reboot scenarios. This pin was left disconnected on the hardware which allowed it to float between binary logic states. If this occurred during startup it would cause an error that would prevent the FMU from booting.

The fix was to define the pin at boot time and rigorously test to ensure that no uncommended reboots were occurring. Additional watchdog mechanisms in ArduCopter 4.0 improved the handling and detection of boot and reboot faults; which allowed for more thorough testing and vetting.

The update has now been fully tested and is ready for deployment.

Applying the Update

Step 1

Download and install the latest version of Mission Planner

  • Use the link below to download the latest version of Mission Planner

    • Note: Only the later version of the software have the required capability

  • Install the software

Mission Planner Download Link

Step 2

Connect to the aircraft using Mission Planner

  • Use a USB micro cable to connect the and computer

    • Note: This must be done over USB. It will not work over a telemetry modem

  • Select the com port in the top right of the mission planner screen

    • Note: Use the comport with “Mavlink” in the title

  • Click connect

  • Wait for connection to complete

Step 3

Ensure the flight Controller has at least 20,000 bytes (20kb) of free memory

  • Open the “Data” screen by selecting the button in the top left of the window

  • Open the “Quick” tab on the bottom left pane

  • Double click on one of the displayed values to change the value displayed

  • Select “Freemem” from the dialog box that appears

  • Ensure that the value is above 20,000 before proceeding

    • If it is not contact support@bfdsystems for further instructions

Step 4

Perform Bootloader Update

  • Open the “Setup” screen by selecting the button in the top left of the window

  • Select “Install Firmware” from the left menu pane

  • Click on “Bootloader Upgrade”

  • Accept warnings

  • Once complete reboot the autopilot

Step 5

Contact BFD Systems Support

BFD Systems – 2020