Radio Link & Latency optimisation
Setting up TBS Crossfire with the Jumper T15, choosing the right packet rate, and why the DJI Goggles 3 race mode is the biggest lever against latency.
TBS Crossfire with the Jumper T15
Insert the module
Put the TBS Crossfire Micro TX V2 into the JR module bay, set External RF to "CRSF".
Create the model
New model, channel map AETR1234 (Betaflight default).
Bind
Open the Crossfire configuration tool, put the receiver into bind mode, "Bind" in the transmitter menu.
Enable in Betaflight
Ports tab: enable Serial RX; Receiver tab: protocol CRSF.
Choosing the right packet rate
| Packet rate | Latency | Recommendation |
|---|---|---|
| 150 Hz | ~6.7 ms | ✓ For racing/close range — this recommendation |
| 50 Hz | ~16–17 ms | Only for genuine long-range flying |
| Dynamic | variable | Not recommended |
The Betaflight developers explicitly advise against it: the RC signal smoothing is tied to a fixed packet-rate value and does not work correctly with a dynamically changing rate.
DJI Goggles 3 & Race mode
For minimal video latency with the O4 Air Unit, the Race mode in the DJI Goggles 3 is the decisive lever.
| Mode | Latency | Image quality |
|---|---|---|
| Race mode | 15 ms | 1080p / 100fps |
| Normal/Quality mode | higher | higher, not optimised for racing |
With Goggles 3 + race mode, latency at 1080p/100fps is only 15 ms — the lowest value in the entire O4 system. For comparison: Goggles 2 / Integra are below 30 ms, roughly twice as high.
Activation
Goggles → Settings → Transmission Mode → Race mode (instead of Normal/Quality). The order matters for the firmware update: goggles first, then the air unit — otherwise you get binding problems.
Downloads
These radio-link topics are part of the continuous Complete Guide — combined there in the right order with all the other steps.