AHRS Troubleshooting


AHRS Troubleshooting

Table Of Contents


1. I cannot get the new top to fit on the case.

(Note: applies to the first two generations of the AHRS upgrade. Not applicable for the v3 upgrade sold starting 5/1/2018.) This is usually caused by the light pipes (small clear plastic tubes that go from the top to board). You will need to trim them. This can be done using a pair of sharp-edged wire cutters or toenail cutters. Cut off a very small amount (1/16″) from each pipe and check the fit. Repeat until the top fits properly.

2. I need to remove the board so I can change the data card. How do I get the standoffs out?

(Note: applies to the first two generations of the AHRS upgrade. Not applicable for the v3 upgrade sold starting 5/1/2018.) The easiest way is to remove the three screws that connect the board to the standoffs. Using a pair of needle-nose pliers, gently grip the standoff and rotate it to the left. Repeat until the standoff is loose enough to be removed. If you must, grip the standoff by placing one side of the nose of the pliers in the hole. Do NOT crush the threads.

Running The System With AHRS

1. I have installed the AHRS board per the instructions but the lights do not come on and the fan does not run.

The AHRS software update has not yet been installed on your system. Please update your FlightBox to the latest firmware release. (Note that the AHRS upgrade kit v3 does not include indicator LEDs and requires at least version 1.4r5.)

2. I have installed the software update. When I go to the FlightBox web interface the version appears to be correct, but I do not see the attitude indicator and G-meter on the “GPS / AHRS” page.

You need to do a hard refresh on every page in the web interface to clear out the old version of the page and force the new version of the page to load. On a Windows computer, hold down the Ctrl button and press F5 (Ctrl + F5). On a Mac, hold down the Command and Shift keys and press R (Command + Shift + R).

3. I see the attitude and G-meters on the “GPS / AHRS” page but they don’t move when move the box.

You need to enable the sensors on the Settings page of the web interface. A newly upgraded system will not have the sensors enabled. Go to the Settings page and turn on the switches. They will be labeled as “Attitude Sensor” and “Altitude Sensor”.

4. I don’t see the “Attitude Sensor” and “Altitude Sensor” switches on the Settings page.

You need to do a hard refresh on the Settings page. See #2 above.

5. The attitude indicator on the “GPS / AHRS” page (or the attitude display / synthetic vision background on my EFB app) is showing a strange attitude, but the FlightBox is perfectly straight and level.

You may need to set the orientation to match the way your FlightBox is mounted. On the Settings page,┬átap the “Set AHRS Sensor Orientation” and follow the instructions. If the display continues to sag or otherwise not match the actual orientation, use the “Calibrate Gyros” button to force a recalibration.

6. The GPS on the AHRS board is not getting a lock, or the lock is intermittent. (Only applies to the first generation AHRS upgrade. The v2 and v3 AHRS upgrade kits use an internal or remote USB GPS.)

If you are using the built-in GPS antenna (in other words, you don’t have the remote powered GPS antenna connected) be sure you do not have the pigtail for the remote antenna installed in your top. The pigtail cable crosses over the built-in antenna and can cause reception issues.

If you are not using the remote powered antenna, the FlightBox needs to be mounted in such a way that the top of the case has a clear view of the sky above. If you set it on the floor or on a seat where there is aluminum between the box and the GPS satellites, the system will have a hard time getting a lock.

In some cases there is enough radio frequency interference from other onboard electronics that the FlightBox can have a hard time receiving GPS signals with the built-in antenna. In this case you will want to add the remote powered antenna, which is somewhat higher in gain and can be moved away from the source of the interference.

AHRS and EFB Applications

1. I do not see the attitude display in iFly GPS.

You most likely need to switch to an instrument layout that includes the attitude display. Here is a video that shows you how to do this:

2. The synthetic vision display in ForeFlight is jittery.

Update to version 1.4r5 or later. This replaces the original approximated attitude value with a much more precise value and eliminates the jitter.