

There are several possible causes of a device appearing as "Compatible":
Poor connection
Chipset drivers not installed
Another program is blocking the connection
Windows COM port bug
Device firmware was erased or corrupted
These issues are all fix-able, but it necessary to check each of them in order to narrow down the exact cause.

It's worth checking the connection before going any further.
For some users, this has solved the problem. Our devices require a stable voltage, which some USB ports and hubs may not deliver, especially if they are overloaded.


Your motherboard's chipset drivers handle USB communication.
If these drivers are not installed, your hardware will fail or function intermittently.
To check for faults:

If you see any "Unknown device", this is a possible cause for concern, particularly if the faulting device is "Intel Chipset", "Universal Serial Bus (USB) Controller" or similar

When you plug in your device, it is assigned a COM port (short for Communication Port) to provide serial communication.
Some programs are overly zealous in taking ownership of all the COM ports on your computer. If another program has locked out the connection, MobiFlight cannot communicate.
The device will be detected, but will only be shown as "Compatible".
Note that we have NOT seen any conflicts with SPAD.neXt. Like the vast majority of other software, it behaves nicely with COM ports.
Some programs we have seen blocking the connection:
We have written a diagnostic tool to help uncover what is blocking the connection.
There may not be anything blocking the connection, but we recommend you run the tool to find out.
You can download it HERE. Instructions are contained in the readme.txt.

A COM port (short for communications port) is a numbered channel that Windows uses to communicate with devices that use serial data, such as Arduinos (used inside your Circuit Avionics device) and other specialist hardware. Unlike standard USB joysticks, these devices rely on serial communication, so each one is assigned a unique COM number like COM3 or COM5.
Windows can exhibit buggy behaviour when it comes to numbering your COM ports. Even when you unplug a device, it remembers the COM port information, and over time this can eventually cause conflicts.
We have seen several instances of this Windows bug rendering our hardware "Compatible". There is a simple workaround, which is to clean out the old numbers and allow Windows to begin with a clean slate.
This is a 'clean slate' option which will remove all COM port assignments and reset their numbering. Please close all applications using COM ports and save your work. A reboot is required to complete the reset. Note that it doesn't delete any drivers - it's just resetting the port numbers to remove conflicts.
Download the zip. Instructions are contained in the readme, which will show you how to do the reset.
If you prefer, there is a limited procedure you can try first, which only resets the COM port number of your Circuit Avionics device.
For some users, this was successful, but for others, the full reset was still required.
On MobiFlight Modules window, make note of the COM port number of the Compatible device:




If your device is still showing as "Compatible", the Full Reset procedure, shown above, may be necessary.

You may need to re-upload the firmware onto your device.
See Firmware.