On this tutorial, I’ll information you thru organising the DJI O4 Lite Air Unit in any FPV drone. This contains wiring it to the flight controller, configuring Betaflight OSD, and sharing helpful ideas together with the finest transmission and digicam settings to realize optimum efficiency in your particular wants.
Nonetheless debating whether or not to get the DJI O4 Lite? Take a look at my overview: https://oscarliang.com/dji-o4-air-unit-lite/
The place to Purchase?
You should purchase the DJI O4 Lite Air Unit from the next retailers:
At present, components will not be bought individually, which means in the event you break the digicam or transmission module, you’d have to exchange the whole air unit. Hopefully, spare components will turn out to be obtainable sooner or later to make repairs extra reasonably priced. Nevertheless, the antenna is well detachable and replaceable.
Mounting
The O4 Lite Air Unit is designed for micro-sized FPV drones, comparable to tinywhoop and ultralight quads. Since these small drones usually use a flight controller with a 25.5×25.5mm mounting sample, it’s potential to mount the O4 AU straight on prime as a part of a single stack.
Many trendy frames have devoted areas within the rear for mounting the VTX, however this will likely not all the time work for the O4 Lite resulting from its brief digicam cable (solely 5cm lengthy).
Picture Credit score: Calpulz
The actual problem is mounting the digicam resulting from its unconventional mounting system. When you’ve got entry to a 3D printer, you might design a customized mount in your present body. In any other case, you would possibly must buy a brand new body designed particularly for the DJI O4 Lite. Simply to call a few these new frames:
Moreover, ensure that the antenna is securely strapped to one thing like the cover. The antenna is just friction-fitted, which means the U.FL connector may pop off in a crash.
Disconnecting Digicam and Antenna
It’s potential to disconnect the digicam from the transmission module, however the coaxial cable/connectors are glued in place. Except you may reapply the glue after reconnection, I don’t suggest disconnecting them. Eradicating or changing the antenna is simple although.
Powering the O4 Lite
The O4 Air Unit (Lite) might be powered straight from a 1S, 2S, or 3S LiPo battery (3.7–13.2V). Nevertheless, the Air Unit could turn out to be unreliable and even shut down when the voltage drops beneath 3.7V. Due to this fact, it’s not really helpful to energy the O4 Air Unit straight from a 1S LiPo. As an alternative, energy it from a secure 5V or 9V BEC on the flight controller, which additionally supplies extra safety in opposition to voltage spikes.
Energy necessities:
- Max energy consumption: ~6W
- Present draw at 700mW: 5V 1.2A or 9V 0.67A
- Really helpful BEC: Minimal 5V 2A BEC or 9V 1A BEC (When you’ve got different power-hungry units, think about using a higher-rated BEC)
Flight Controller Connection
The DJI O4 Lite Air Unit makes use of the identical 6-pin connector and pinout because the O3 and O4 Professional, making it plug-and-play with any flight controller designed for present DJI Air Items. Nevertheless, it is best to all the time double-check the wiring upon connection to keep away from any surprises.
Pinout of the 6-pin connector:
- VCC: Energy provide
- GND: Floor
- RX/TX: Required for OSD and telemetry (e.g., displaying battery voltage and arming detection)
- GND and SBUS: For DJI Distant Controller (elective)
Not like the O4 Professional, the O4 Lite doesn’t have solder pads. If you wish to solder it on to the flight controller, you’ll need to lower off the connector from the cable and strip the wires.
In case you are not utilizing a DJI Distant to regulate the drone, and are as a substitute utilizing your individual radio receiver, it’s really helpful to take away the SBUS wire (DJI HDL) from the connector. This may forestall potential conflicts. Use a pointy instrument, comparable to a pin or needle, to barely carry the tab within the connector and pull the wire out. On this case you might also take away the extra floor wire (brown).
Activation
As soon as the O4 Lite is linked to the flight controller (FC), it’s time to activate it. If the Air Unit was beforehand activated, this step will not be required.
Professional Tip: that the O4 Air Unit should be powered by a battery or a accurately rated energy provide throughout activation. Not like the O3, it can’t be activated utilizing simply the USB-C cable. Though the USB-C cable will not be included, any USB-C knowledge cable will work.
Obtain DJI Assistant 2 (Shopper Drone Collection): https://www.dji.com/nl/downloads/softwares/dji-assistant-2-consumer-drones-series.
When you’ve got put in it, it’s nonetheless a good suggestion to obtain and re-install the newest model.
Professional Tip: activation CANNOT be achieved within the DJI Fly App.
Firmware Replace
Whereas linked to DJI Assistant 2, examine if new firmware is out there in your O4.
Professional Tip: For firmware updates, you may safely unplug the battery through the course of to keep away from heating.
Pairing DJI Goggles 3 with O4 Lite
Earlier than pairing, guarantee your Goggles 3 firmware is up to date to the newest model. With out this replace, you gained’t get the O4 Professional and O4 choices within the menu. Comply with these steps:
Replace Firmware
- Activate the Goggles 3 and join them to your pc utilizing a USB-C knowledge cable.
- Replace the firmware by way of DJI Assistant 2.
Professional Tip: If the Goggles 3 doesn’t seem in DJI Assistant 2, navigate to the goggles menu:
Settings → About → OTG Wired Connection and allow it.
Choose O4 Air Unit Professional within the Goggles Menu
- Go to the goggles menu, navigate to Standing → Swap, and choose “DJI O4 Air Unit.”
Enter Bind Mode
- Press and maintain the ability button on the goggles till they begin beeping, indicating they’re in bind mode.
Energy on the O4 Air Unit
- Look ahead to the LED on the Air Unit to show crimson.
- Press the bind button on the Air Unit. The crimson LED will start flashing slowly, indicating it’s in bind mode.
Full Binding
- Binding is profitable when the LED on the Air Unit turns stable inexperienced, and the goggles show the digicam feed.
Pairing Goggles 2/Integra with O4 Lite
To make use of the O4 Air Unit with Goggles 2 (or Integra), you’ll must replace the firmware on each units. And don’t fear, you’ll nonetheless get compatibility with the O3 Air Unit, in addition to older DJI FPV Air Items and the Vista system.
Professional Tip: When you’re utilizing a Mac and encounter connection points (e.g., Goggles 2 not showing in DJI Assistant 2), it is a identified drawback. Sadly, there isn’t a dependable repair. A workaround is to replace utilizing the DJI Fly App in your smartphone or swap to a Home windows PC for the firmware replace.
After the replace, go to the goggles menu and choose both O4 Air Unit or O3 Air Unit underneath the settings.
Press the hyperlink button between the lenses on the Goggles 2 to enter bind mode.
Energy on the O4 Air Unit and look forward to the LED to turn out to be crimson. Press the bind button on the Air Unit. The crimson LED will flash, indicating bind mode. Binding is profitable when the LED turns stable inexperienced, and the digicam feed seems in your goggles.
Switching Between Professional and Lite
When you use each the O4 Professional and O4 Lite, keep in mind to modify between them within the goggles menu earlier than flying. Every time you fly with a unique unit, you’ll must manually choose the corresponding Air Unit within the goggles settings.
Unlock FCC Mode
In case your Goggles 3 are shipped with CE mode (to adjust to European laws), they are going to be restricted when it comes to output energy (solely 25mW) and channels. There will probably be only one obtainable channel within the 40MHz mode and three obtainable channels within the 20MHz mode.
In FCC mode, it is best to have the utmost 1200mW output energy possibility, and there needs to be 7 obtainable channels within the 20MHz mode, and three obtainable channels within the 40MHz and 60MHz mode.
For goggles in CE mode, it’s potential to carry out the “FCC hack” to unlock increased output energy (extra vary and sign penetration) and extra channels (permits extra pilots within the air on the identical time), however solely do that if it’s authorized the place you fly.
To modify to FCC mode, merely get the file “ham_cfg_support”, unzip it to the foundation listing of the SD card and put it within the goggles, energy on goggles, that’s it.
Obtain file right here: https://drive.google.com/file/d/1ug2U_i5kdrKQQ2I17NLJBXm2tKQeNj5Q/view?usp=share_link
To examine in case you are in FCC mode, go to Settings => Transmission => Channel Mode, swap to Guide, underneath 40MHz or 60MHz bandwidth, it is best to see 3 channels obtainable in FCC mode. If it would solely present 1 channel there, you might be in CE mode.
As soon as FCC mode is unlocked, you gained’t should do it once more. You’ll be able to return to CE mode by manufacturing unit reset the goggles (within the menu Settings => About).
Setup OSD in Betaflight
The DJI O4 Air Unit absolutely helps the Betaflight OSD, together with the Betaflight OSD menu and all obtainable OSD parts.
Go to the Presets tab, and seek for “dji”, the “FPV.WTF MSP-OSD” preset ought to pop up. In choices, choose the UART you’ve got linked to the O4 Lite Air Unit.
To allow HD OSD, go to the settings menu within the goggles, Settings > Show > Canvas Mode, and choose HD OSD.
This lets you show the OSD with smaller fonts and drag OSD parts all the best way to the sides of the display screen. If you choose Regular Mode, the font will seem a lot bigger.
Lastly, go to the OSD tab in Betaflight Configurator. Below Video Format, guarantee HD is chosen.
Setup DJI Distant Controller
When you’re utilizing a third-party radio hyperlink, you may skip this part.
Utilizing DJI’s distant controller eliminates the necessity to wire a separate radio receiver to the flight controller, because the DJI O4 Air Unit additionally serves as an RC hyperlink. This simplifies the setup course of. Nevertheless, there are just a few downsides to contemplate:
- Primary performance: DJI’s distant controllers lack the superior options and management precision provided by extra subtle techniques like ExpressLRS.
- Failsafe dependency: For the reason that video and radio indicators share the identical hyperlink, shedding the video sign additionally leads to a failsafe, which isn’t the case with superior RC hyperlinks like ExpressLRS that usually outperform video hyperlinks considerably.
Suitable DJI Distant Controllers:
- RC2: Works completely with the Goggles 2 and Integra.
- RC3: Works completely with the Goggles 3 and N3.
Pairing the DJI Distant Controller 3:
- Energy in your goggles 3 and RC3.
- Lengthy-press the energy button on each the goggles and distant controller to enter linking mode.
- As soon as the units are efficiently linked:
- The goggles will cease beeping and show the dwell view.
- The distant controller will cease beeping.
Configuring Betaflight:
- Within the Ports tab, allow Serial RX for the UART linked to the SBUS wire.
- Within the Receiver tab, set the protocol to SBUS (by way of UART).
Movies Recording
The O4 Air Unit has 23GB of onboard reminiscence for recording flight footage. Relying on the decision you choose, it may retailer roughly 30 to 45 minutes of recordings. Sadly, it doesn’t help micro SD playing cards, so ensure that to offload footage often; in any other case, the unit would possibly cease recording till you release reminiscence.
You’ll be able to begin recording by utilizing the Document button within the goggles’ prime menu. Alternatively, you may configure the O4 Air Unit to begin recording mechanically whenever you arm the quad within the system menu. Navigate to Settings → Digicam → Superior Digicam Settings to allow this selection, which many pilots discover extra handy.
Obtainable Resolutions & Body Charges:
- 4K 60fps
- 4K 50fps
- 4K 30fps
- 1080p 120fps
- 1080p 100fps
- 1080p 60fps
- 1080p 50fps
- 1080p 30fps
Obtain Video
To obtain movies, plug within the USB cable, an exterior drive will seem in your pc, containing all of the recorded footage. To obtain video off the Goggles, it is best to energy them on first, in any other case connecting the USB cable does nothing.
Video Stabilization
Video stabilization helps easy out flight footage by lowering shakiness and vibrations. The O4 Air Unit helps two stabilization strategies: RockSteady and Gyroflow.
- RockSteady is built-in and might be enabled within the goggles’ menu. It stabilizes footage mechanically throughout recording, providing respectable outcomes with minimal effort. To allow RockSteady, set Recording Stabilization to ON.
- Gyroflow is an open-source, software-based stabilization instrument that gives extra flexibility. It lets you fine-tune stabilization settings in post-processing. With Gyroflow, the uncooked footage stays unstabilized, supplying you with full management over how a lot stabilization to use. To make use of Gyroflow, set Recording Stabilization to OFF.
For finest outcomes with Gyroflow, use the next settings:
- Side Ratio: 4:3
- Digicam FOV: Broad
- Recording Stabilization: OFF
Gyroflow is straightforward to make use of, and I’ve created a tutorial explaining the way it works: https://oscarliang.com/gyroflow/
The best way to Keep away from Jello and Vibration
Just like the O3, the O4 digicam is extremely delicate to vibrations, making it essential to isolate the digicam from vibration sources or eradicate vibrations altogether.
Keep away from utilizing 24kHz PWM frequency in your ESC settings, as decrease PWM frequencies can enhance vibrations and noise. As an alternative, use a increased frequency, comparable to 48kHz, for optimum efficiency.
Mounting the O4 digicam straight on carbon fiber or CNC aluminum is not really helpful, as vibrations can switch straight from the motors to the digicam, inflicting jello in your footage. As an alternative, use a delicate mounting materials that gives vibration dampening. Many new frames embody silicone or rubber inserts/spacers particularly designed for mounting the O4 FPV cameras, serving to to scale back vibrations considerably.
Finest O4 Professional Settings
Not like the O4 Air Unit Professional, the usual O4 Air Unit solely helps one coloration mode: Regular. There may be no D-Log M mode, which is most popular by cinematographers. Whereas this will likely restrict superior coloration grading choices, it simplifies the decision-making when selecting the most effective settings.
Not like the O4 Air Unit Professional, the O4 Air Unit solely has one coloration mode: Regular. There isn’t any D-Log M mode which is most popular by cinetographers. However this limitation additionally makes our resolution simpler relating to what settings we must always run.
Really helpful Digicam Settings for the Finest FPV Expertise (For individuals who prioritize low latency and don’t care a lot about recording high quality):
- Side Ratio 4:3
- Video High quality: 1080p 100fps (presents the bottom latency)
- Digicam FOV: Broad
- Auto ISO Restrict: 6400
- Auto Mode
Really helpful Digicam Settings for the Finest HD Recording (For these Utilizing ND filter, Gyroflow stabilization, and Coloration grading):
- Side Ratio 4:3
- Video High quality: 4K 60fps (30fps could be higher for low gentle, however it may enhance latency, making correct flying tougher.)
- Digicam FOV: Broad
- Recording Stabilization: OFF
- Sharpness: -2 (you may enhance sharpness in post-editing if wanted)
- Noise Discount: 0 (or +1 in low-light conditions to scale back noise in darkish areas)
- Digicam Mode: Guide
- Shutter Velocity: 1/120
- Auto ISO
- Auto ISO Restrict: 200 – (set this as little as potential to keep away from graininess; nonetheless, too low would possibly make the picture too darkish.)
- White Steadiness: Put White Steadiness on Auto first and see what the system select, then lock in with that worth, so WB is mounted throughout flight
Really helpful Digicam Settings for First rate HD Recording (For individuals who desire little to no enhancing):
- Side Ratio 4:3
- Video High quality: 4K 60fps
- Digicam FOV: Regular
- Auto ISO Restrict: Set as little as potential in your lighting situations. If not sure, depart it on the default (6400). Word that increased ISO could result in grainier photos in darkish areas, nevertheless it ensures visibility.
- Recording Stabilization: ON
- Coloration: Regular
- Digicam Mode: Auto
- White Steadiness: Auto
Really helpful Transmission Settings for Solo Flying
- Race Mode: OFF
- Transmission Energy: Use the very best energy stage legally allowed, or simply set it to Auto.
- Channel Mode: Guide
- Bandwidth: 60MHz (60mbps bitrate)
Really helpful Transmission Settings When Flying with Different Pilots
- When flying with different DJI pilots: Think about lowering transmission energy and utilizing smaller bandwidth.
- When flying with pilots utilizing different FPV techniques (e.g., Analog, HDZero): Allow Race Mode to scale back interference.
Race Mode
Race Mode is a function designed particularly for FPV racing, obtainable solely on the DJI Goggles 3 and N3, however not on the Goggles 2 and Integra resulting from {hardware} limitations. It optimizes the system for low-latency efficiency and minimizes interference in race environments by aligning its channel frequencies to Race band. Right here’s what Race Mode presents:
- Lowest Latency: Race Mode forces the system into 100fps with a 20MHz bandwidth, reaching latency as little as 20ms.
- Channel Alignment: Channels align with normal race band frequencies, making it extra suitable with different FPV techniques.
- Cleaner Sign: The telemetry hyperlink now operates on the identical static frequency because the video sign, lowering interference with different pilots. When the Air Unit is off, the goggles cease transmitting altogether, permitting pilots to stroll round with out affecting others.
- Commerce-offs: Narrower bandwidth and decrease energy output scale back vary and penetration, making it unsuitable for freestyle, cinematic, or long-range flying. Nevertheless, these limitations are acceptable for racing, which usually happens in open fields.
Warning: Keep away from powering in your Air Unit whereas others are within the air, because it momentarily sweeps throughout the band, doubtlessly inflicting interference for many who are nonetheless within the air. For all different forms of flying, regular mode presents higher RF efficiency.
Transmission Energy High-quality Tune
This function lets you fine-tune the output energy of your VTX by ±1mW to ±7mW to make sure compliance with racing occasion laws. For many customers, this setting isn’t crucial until you’re attending a regulated racing occasion the place exact energy ranges are required.
Spectator Mode
The Spectator Mode permits you to watch different pilots flying with the O4 Air Unit, nevertheless it comes with compatibility limitations:
- Goggles 3 and N3 customers can solely spectate different pilots utilizing G3 and N3.
- Goggles 2 and Integra can solely spectate different pilots utilizing G2 and Integra.
Spectator Mode doesn’t work throughout these two generations, so make sure you’re utilizing the identical technology goggles because the pilot you wish to spectate.
Conclusion
Organising the DJI O4 Lite Air Unit in your FPV drone is simple, particularly in the event you comply with the wiring, mounting, and configuration steps outlined on this information. Whereas the O4 Lite has some limitations in comparison with the O4 Professional, it stays a robust and light-weight possibility for micro FPV drones. Be sure to often offload recorded footage, optimize mounting for the antenna and digicam, and select a dependable energy supply to make sure the most effective efficiency. Comfortable flying!
