Installing An AHRS Upgrade

Byssokol

Installing An AHRS Upgrade

Upgrade Kit Installation

This guide presumes you are upgrading a FlightBox system assembled from a kit or purchased as an assembled, running system (FB1X). If you are using a generic Stratux system the process may differ.

Part 1: Software Installation

Before installing the hardware upgrade you will need to make sure your FlightBox is running the latest FlightBox software. You will need at least version 1.3r1, and preferably version 1.4r4. There are four options for updating the software on your FlightBox system:

  1. You can install the latest version from the FlightBox Utility iOS or Android app.
  2. You can install the update using the manual update process.
  3. You can re-image the data card with a complete beta image.
  4. You can order a pre-imaged card from the web store.

 

Installing An Update File Using The Web Interface

The video above walks you through the manual update process. For assistance with the other options, please see the Support section, or place an order on the web store.

Part 2: Hardware Installation

Video Tutorial

Please watch the installation / upgrade video before starting on the installation process.

Step 2: Remove The Top / Screws

  1. Start by removing the three 1/4″ screws that hold the top to the case. Keep these screws – they will be re-used in a later step.
  2. Disconnect the fan power cable from the 40-pin header on the Raspberry Pi.
  3. Discard the old fan and the top, they will not be needed.

Step 2.1: IF YOU ARE INSTALLING A NEW DATA CARD OR RE-IMAGING YOUR CARD:

If you purchased a new data card or are going to re-image the card you will need to disassemble the system further to remove the old card and replace it. To do so:

  1. Remove the nuts from the bulkhead connectors and pull the bulkhead connectors out of case wall.
  2. Remove the four screws holding the Raspberry Pi computer assembly to the case.
  3. Carefully lift the assembly out by lifting up on the side of the Raspberry Pi with the 40-pin header.
  4. Remove the data card from the slot on the bottom of the Raspberry Pi.
  5. Install the new card (or re-image the existing card and re-install it).

 Step 2.2: IF YOU ARE INSTALLING A GPS

If you purchased either the internal or remote GPS module, now is the time to install it. To do so:

  1. Remove the nuts from the bulkhead connectors and pull the bulkhead connectors out of case wall.
  2. Remove the four screws holding the Raspberry Pi computer assembly to the case.
  3. Carefully lift the assembly out by lifting up on the side of the Raspberry Pi with the 40-pin header.
  4. Insert the GPS’s USB connector into the top-center GPS port on the Raspberry Pi.
  5. Reassemble the system.

Step 3: Prepare The New Top

  1. The latest batch of upgrade kits include a pre-assembled top. No assembly required.

Step 4: Mount The AHRS Board

  1. Remove the two 1/4″ screws holding the Raspberry Pi to the case on either side of the 40-pin header. Leave the screws near the audio jack (the small circular connector that sticks through the case) and the power jack. Keep the two screws – they will be re-used.
  2. Screw the two white nylon standoffs through the holes in the Raspberry Pi and into the case. You may find it easiest to do this by temporarily screwing the black 1/4″ screws removed in the previous step into the top of the standoff, then screwing the assembly (the standoff + screw) into the hole. DO NOT OVER TIGHTEN – THE NYLON THREADS STRIP EASILY. (If you use the screw trick, grip the standoff with small pliers to loosen and remove the screw.)
  3. Mount the AHRS board on the 40-pin header making sure that it lines up correctly. The matching 40 pin socket on the AHRS board should cover all pins. Gently push the board onto the pins until it seats against the three standoffs.
  4. Use the two 1/4″ screws removed previously to secure the AHRS board to the standoffs.

Step 5: Assemble The System

  1. Place the new top beside the bottom portion of the case.
  2. Carefully connect the small white two pin JST connector on the end of the fan cable to the matching two pin JST connector on the board.
  3. Place the top on the case and align the three screw holes in the case bottom with the nuts embedded in the three mount points in the new top. If necessary, trim the light pipes to allow the top to seat properly.
  4. Use the three 1/4″ screws removed in the first step above to secure the top to the case.

Step 6: Enable The Sensors / Verify The Upgrade

Please see the following video for assistance enabling the AHRS features:

YOU MAY HAVE TO DO A HARD REFRESH ON YOUR BROWSER TO GET THE NEW PAGES TO LOAD. Use Ctrl + F5 on Windows or Command + Shift + R on Mac. You may need to do this on each of the pages in the web admin.

After the update is complete you may need to go to the settings page and turn on the “Attitude Sensor” and “Altitude Sensor” buttons. This will enable the drivers that read the AHRS and altimeter. Once you have the sensor buttons enabled you can check the Status and GPS / AHRS pages on the web interface to make sure the system recognizes the board.

The GPS will immediately begin searching for satellites to track and you should see a fix / lock within 2 – 3 minutes (presuming the system can receive signals in your location – metal hangar roofs are notoriously impervious to GPS signals).

To test the attitude sensors, go to the AHRS / GPS page and observe the AHRS test indicator (attitude indicator). When you move the FlightBox you should see the indicator display the attitude corresponding to the box’s orientation in space. To adjust the orientation of the system for your preferred mounting, please see below.

Status LEDs and Fan Controller

Two minor features of the AHRS board are status annunciation and control of the cooling fan. The board has three LEDs, one for power, one for GPS status, and one for ADS-B status.

Power – indicates green when the board is receiving power and the core software is running. The LED typically takes 20 – 30 seconds after power is applied to turn on.

GPS – blinks orange while the system is attempting to acquire a fix; solid orange once a fix has been established. This LED will remain off (dark) until the GPS gets an initial lock.

ADS-B – off indicates no reception on either band; blinking blue indicates reception on one band within the past 60 seconds; solid blue indicates receiving on both bands within the past 60 seconds.

Fan – automatically comes on when the CPU temperature reaches 40° C. The fan will turn on periodically after several minutes operating in a room-temperature environment.


Mounting / Orientation

The current version of the firmware allows you to select your own preferred orientation (i.e. the “forward” and “up” for the system). Please see the video linked here to set the orientation. Below is the default orientation for the system:

The system should be mounted as securely as is practical / legal. Vibration and motion relative to the airframe decrease the accuracy of the attitude solution provided by the system. With regard to pitch, the unit should be mounted at or very near the aircraft’s level pitch attitude in level flight. (Note that this can be significantly different from the aircraft’s pitch while parked on the ground.)