Hello all.

I'm not completely sure if I'm having an issue here, but I just finished building up a quad, and I setup the DJI goggles OSD LQ, and I'm constantly getting 99. I know that the usual LQ goes from 0-300 so this should be almost always on 99. However, I wanted to test this, and I changed my Crossfire micro to have a max output power of 25mW, and put the quad in the garage, with the transmitter upstairs on the other side of my house, with it still being 99. Is this just crossfire being really good or is something wrong? 

Thanks.

What version of Betaflight are you using? There were changes to LQ and RSSI in recent Betaflight versions. Previously it was always 99%.

The actual Crossfire LQ scale only goes from 0-100%. It is Betaflight that then merges that value with the RFMD value and then outputs a value of 0-99, 0-300, or a format of 0-2:0-99 depending on the version of Betaflight you are running. But those last two formats only ever appear in analogue goggles or in Shark Byte HD goggles. The DJI FPV Goggles don't support the real Crossfire LQ value which is why you have to do the hack/workaround to make LQ value appear to the DJI goggles as if they are a 0-99 RSSI value.

When displaying LQ as a 0-99 RSSI value it will only ever start dropping if you have the RF Profile locked to 150Hz or if you are using the dynamic RF Profile and the RF Mode switches from mode 2 (150Hz) to mode 1 (50Hz). You will never see anything less than 99 displayed while in dynamic RF Profile and with the RF Mode still on mode 2. The RF Mode will only drop to mode 1 when you get quite a distance out, even on 25mW, so what you're seeing with the LQ value seemingly "stuck" on 99 is likely correct.

The are a few ways you can test that the value does actually drop so you have some peace of mind when out in the field:-

1. Set the output power of the Crossfire module to 25mW and put your transmitter in a microwave oven which acts as a faraday cage thus it will do a better job of blocking RF waves. Obviously don't switch on the microwave Then take your quad and goggles and start walking away from the house while keeping an eye on the LQ value in the OSD of your goggles. You should eventually see it start to drop. You might need to walk quite a distance, so be prepared for that.
   
   
2. Do the same as (1) but set the RF Profile on your Crossfire Nano RX to forced 150Hz (which is RF Mode 2). Because you have prevented Crossfire from dynamically changing the RF Mode, the LQ value should start dropping sooner.
   
   
3. Put your quad in the microwave oven instead of the transmitter and under the model settings on your transmitter, go to the TELEMETRY page where you should see the "RQly" and "RFMD" sensors in the list with flashing asterisks next to them. Then walk away from your house while watching those two sensor values and you should see one or both of them eventually drop. If the RFMD changes to 1 (or you already have the RF Profile locked to 150Hz), then when the RQly value is less than 100% you should also see the 99 value in the OSD of your goggles start dropping.