DJI O3 Air Unit review: Cinematic Digital FPV system

I ordered the DJI O3 Air Unit to review it on the first day of its official announcement. I have already tested its predecessors, the original Air Unit and Caddx Vista\RunCam Link, and I had big expectations from this new release.

In 2019, DJI changed the FPV scene with its first compact HD digital FPV system, which provides outstanding image quality and a truly immersive first-person view experience. After three years, analog FPV is still being used, but mainly for budget-constrained builds. These two wireless video technologies vary a lot. While Analog systems transmit the electrical signal as it is, prone to interference and external noise, HD Digital systems convert the electrical signal into digital data adding error correction information to transmit crispy clear video to your FPV Goggles.

The newest Air Unit O3 is not just smaller and lighter but also provides a much longer range than its predecessor. Featuring O3+ video transmission, the DJI O3 Air Unit provides a host of powerful video transmission capabilities and a range of up to 10 km. Control your drone with snappy responsiveness and get a crisp, ultra-sharp live feed. The 2T2R omnidirectional antennas further ensure the stability and smoothness of video transmission within the signal coverage range.

The DJI O3 Air Unit features a wireless video transmission resolution of up to 1080p while maintaining a high frame rate of 100 fps. It also supports the H.265 video coding format, presenting additional clarity and smoothness in your live view. The onboard 20GB flash memory is also a great addition allowing you to record the journey of your flights at 4K@60fps or 2.7K@120fps for slow-motion shots.

Key features

• Embedded remote controller receiver (compatible with DJI FPV transmitter 2);
• O3+ low-latency 30 ms 10 km Digital Video Transmission;
• Multi-antenna anti-interference digital transmission;
• 1080p/100fps H.265 Video Transmission;
• Onboard 4K@60fps video recording;
• RockSteady electronic image stabilization (EIS);
• Wide range of voltage input (7.4-26.4 V / 2-6S compatible);
• Canvas mode with full Betaflight OSD Support and PID adjustment;
• Compatible with Multiple DJI Devices (Goggles 2, FPV Goggles V2, and FPV controller 2).

DJI O3 Air Unit hands-on review (not sponsored!)

Initially, I wanted to try a DJI AVATA drone with a similarly spec-ed FPV transmission system. As the latest firmware update forced it to be used with a mobile device for remote ID, I was happy that I opted for the Air Unit O3 and built my own FPV drone. About five years ago, DJI stopped direct delivery to my country, so I had to order the O3 in the neighboring country. I placed my order one hour after the official announcement and got it four days later.

At a glance

O3 air unit consists of a camera, a video transmitter, and an antenna with a total weight of approximately 40 grams (1.41 ounces). The O3 VTX unit measures 32.5×30.5×14.5 mm, and it has an FC connector, Camera socket, USB Type-C plug, micro SD slot, Status LED, and Bind button. It has a 25.5×25.5mm mounting pattern with M1.6 screws. The case is made of durable aluminum that doubles as a heat sink for cooling, so expect this to get very hot during usage. Actually, without good airflow, it is not recommended to keep it powered on for more than a few minutes.

The new Air Unit has two separate U.FL antenna connectors. In order to save some space and allow easy mounting, DJI put two antennas in the same housing, so it appears like a single antenna. It operates at 2.4GHz for RX and 5.8GHz for RX/TX frequencies. While in FCC mode (US) max possible range is 10 km (6.21 miles), in CE mode (Europe region) is only 2 km (1.21 miles).

The camera module measures 21.2×20×19.5 mm, with two mounting screws on each side. Using my Elegoo Neptune 3 Pro, I already 3D printed a few TPU camera mounts. According to DJI, their O3 AU camera module is compatible with DJI Avata ND Filters Set (ND8/16/32). Its 1/1.7-inch sensor and f/2.8 lens provide a 155° super-wide field of view (FOV) footage for stunning visual effects. DJI used the same sensor in many recent products, such as the Avata drone, Action 3, and the Pocket 2 gimbal camera. D-Cinelike color mode allows more creative freedom for color grading, letting you post-process and adjust your footage. Furthermore, the O3 Air Unit features RockSteady, DJI’s game-changer Electronic Image Stabilization (EIS) technology. Additionally, IMU data is stored, so the footage can be further stabilized in compatible software using gyro-based information.

Canvas Mode

Canvas Mode enables BetaFlight flight controllers to display OSD elements (such as battery voltage, flight mode, temperature, and flight distance) on the screen of the FPV goggles. Users can configure which OSD elements to display and where to display them on the screen using the Betaflight Configurator software.

To get OSD working, you need to run the following commands in CLI:

• set osd_displayport_device=MSP
• set displayport_msp_serial=x (where x is the UART port number-1, in my case, I used 5 for UART6)
• save

Pinout and wiring

The connection between the O3 Air Unit and the Flight controller is made by using the provided 3-in-1 cable (power+data+rx). Both ends of the cable are identical (6 pins), unlike in the case of the original OA, where one end has six pins and the other eight pins.

• RED: Power (7.4-26.4 V)
• BLACK: Power GND
• WHITE: UART RX (Connects to Flight Controller OSD TX, 0-3.3 V)
• GRAY: UART TX (Connects to Flight Controller OSD RX, 0-3.3 V)
• BROWN: Signal GND
• YELLOW: DJI HDL (Connects to Flight Controller S.Bus, 0-3.3 V)

My favorite part about this is how many fewer wires there are and how clean it can look when you build it. Using the built-in receiver, you will need just one cable between the O3 and the flight controller. No soldering is required.

Caution: Some flight controllers, such as the SkyStars F722 MINI HD Pro, can have reversed pin orders. Before connecting the AU O3, always check if the signal Power, GND, RX, TX, GND, and DJI HDL goes to the corresponding pin on the FC.

Built-in Radio Control Link

The O3 also has an SBUS output, just like the first-generation Air Unit. It’s compatible with the DJI remote controller V2, which, since the release of the AVATA, has been very sought after. Of course, it is still possible to fly your DIY FPV drone with an external receiver like the Crossfire, FrSky, or ExpressLRS.

Pricing and availability

You can order the O3 AU kit from DJI or other online retailers, such as Banggood, for starting price of $229 (259 € – may vary due to VAT). This price includes the VTX module, Camera, FC cable, and 2-in-1 antenna.

Technical specifications

DJI O3 Air Unit: Activation

Like its predecessors, the original DJI Air Unit and Caddx Vista, you must activate the O3 Air Unit before use. The process is straightforward and can be done using the DJI Assistant 2 APP (Consumer Drones Series) available for Windows and macOS. You just need to connect the O3 to your computer using a USB cable. An active DJI account is required for activation. The same APP allows updating the firmware on the O3 Air Unit, DJI Goggles 2, and the Remote Controller 2.

DJI O3 Air Unit: How to link with DJI FPV Goggles V2?

After activation, you need to link (pair) the O3 AU with your Goggles. Before proceeding, you need to upgrade both devices’ firmware. In theory, after upgrading to V01.04.0000 (2022-11-15) firmware, O3 AU mode should be available in Goggles V2 under the “Switch Aircraft Model” menu. Following Joshua Bardwell’s video, I found that for this, you need to toggle first to DJI FPV mode.

After DJI O3 Air Unit is activated on the DJI FPV goggles V2, you can put both devices in bind mode by pressing the ‘Link’ button using a toothpick. Once linking is successful, the linking status indicator of the O3 air unit turns solid green, and the goggles stop beeping. For linking process is enough to power the air unit via a USB Type-C cable.

DJI O3 Air Unit: Do you still need a GoPro?

The O3 Air Unit can’t replace your GoPro camera entirely, but in most cases, the results are satisfactory without needing a 2nd camera. By comparison, the O3 AU camera has a 1/1.7-inch 48MP sensor, and the newest GoPro has a 1/1.9-inch 27MP sensor. The biggest problem with the O3 is that you can’t customize image quality parameters like in the case of a GoPro. Also, having a single camera for both jobs, you must prioritize onboard recording or FPV quality. You can’t have both at their highest performance.

The O3 system provides 4k@60fs onboard recording with lots of details and a nice color palette in less than 50 grams. In contrast, my GoPro 10 weighs 158 g and can record 4K@120fps videos.

Firmware upgrades

Date: 2023.1.6
DJI O3 Air Unit Firmware: V01.02.0000
DJI FPV Goggles V2 Firmware: V01.06.0000
DJI Goggles 2 Firmware: V01.04.0000
Remote Controller Firmware: V02.00.0500

What’s New?
Added support for the DJI O3 Air Unit to record video at 4K@30fps, 2.7K@30fps, and 1080p@30fps. When used with DJI Goggles 2, 4K@120fps, 2.7K@120fps, and 1080p@120fps are also supported.
Added ability to set the sharpness and noise reduction value. Go to Settings  Camera  Advanced Camera Settings in the goggles menu to set the value.
The time for DJI O3 Air Unit to enter a low-power state after stopping the aircraft motors has been changed from three seconds to six seconds.
Improved D-Cinelike to 10bit, providing more possibilities for post-processing.
Optimized the camera exposure in some backlighting scenarios to avoid over-dark in shadow areas.
Optimized the remote controller signal in some scenarios.

Date: 2022.11.22
DJI O3 Air Unit Firmware: V01.01.0000
DJI FPV Goggles V2 Firmware: V01.04.0000
DJI Goggles 2 Firmware: V01.02.0000
Remote Controller Firmware: V02.00.0300

What’s New?
Added the following video recording specification:
With DJI FPV Goggles V2: 4K@120fps, 4K@100fps
With DJI Goggles 2: 4K@100fps
Added the function to use DJI Assistant 2 (Consumer Drones Series) to update the camera calibration file to guarantee image quality after the camera module is replaced.
Optimized the power consumption strategy in a low-power state to improve the standby time.