DJI HD FPV Air Unit TEARDOWN & OVERVIEW

[@LivyuFPV]

The tools links were malformed... fixed them!

[@typxxilps]

Thanks a lot. I have an air unit that looks similiar but I am not sure if it is the same. I have Goggles Racing edition and purchased a fpv air unit as it is called: box, camera and lot of antennas and cables more or less Are those the same so I could use those with the new googles Remote too ? thanks and forget about your accent that is for sure not russian, much weaker and more western. I can understand you perfectly and if not I can ask ... but I usually get what you mean or meant and mostly I have to check the vocabulary on my side to make sure that I understood things right. So communication form Roumania to Germany successfully established and I guess you will not find many that can complain that they are unaible to understand you - at least compared to indian speaking their interpretation of english.

[@ivanheinzer6829]

Finally someone which did not only show the whole assembled unit! Thank you! Maybe I have some things to add: The connector which is used for the camera cable is a HIROSE DF56-26P-0.3SD. They even use this connector on other drones. The communication is via MIPI CSI-2. If you would be able to generate a valid CSI signal you could hook up anything you like to the air unit. Unfortunatly its not just plug and play because almost every camera/sensor would need it's own driver implementation on the receiver side (Air Unit). The guys from RunCam got it somehow with the Racer 4 but they don't want to talk about it ;-) And one more thing: The Caddx Vista uses almost the same components. They also use the same P1 chip, the same regulators, the same RF components and so on but just another layout and a lighter casing. I really play with the Idea of creating a MIDI -> CSI -> FPGA (something like a XILINX Spartan-7) -> CSI -> Air Unit Converter. Would be awesome to hook up a gopro or something for live transmission...

[@rbhandy]

Hey Ivan, have you had any success with the HDMI - CSI - Airunit Converter? Thanks

[@dfgaJK]

please try a TC358743XBG converter

[@dukevah]

Amazing. At the beginning of the video I had some serious questions. You answered all of them. Thanks lot.

[@kandredfpv]

Nice tear down Livyu. So if I understood you correctly, they're just using a wifi chipset at a non-standard @5.8ghz with an RF power amp frontend to give the 1W output. It might just be 802.11g which would give up to 54Mbps. That uses OFDM with a 20Mhz bandwidth, which would explain why it trashes the analog channels. It's unlikely to be using the newer MIMO-OFDM in 802.11n+ systems (which benefit from multi-path fading) because the antennas are circular polarised in a way that promotes signal correlation i.e. no polarization diversity. MIMO antennas are normally linearly polarized but at different angles to give polarization diversity.

[@Stefan_73]

I'm not getting this. Analog FPV has an approx bandwidth of 20MHz too. ODFM is usually also well behaved in it's spectral behavior.

[@LivyuFPV]

yeah, same thoughts here. But someone would need some nice lab tools to learn more. My spectrum analyzer goes up to 1.5 g and my oscilloscope well nowhere near 6g but I am curious about what they are doing on the rf side.

[@kandredfpv]

@@Stefan_73 well DJI's manual confirms the 20Mhz bandwidth per a channel, although the actual channel spacing is larger. While you're right about analog channel spacing being at least 20Mhz, the actual analog NTSC signal only uses 6Mhz of bandwidth. From what I've heard, the main reason why the DJI air unit doesn't interoperate well side-by-side with analog systems is because the goggles are also emitting, as one would expect for a full-duplex digital communication system. The googles themselves can put out up to 30dbm (1W), I imagine that's enough to start leaking into neighbouring analog channels of nearby pilots.

[@kandredfpv]

@@LivyuFPV nah you'll need something like a HackRF One SDR which goes up to 6Ghz. You might even be able to extract the DVB-T feed (if that's the protocol they're using).

[@MadRC]

Hay man, I’m changing down a bad air unit my self right now. I believed it was over voltaged. It visibly burnt the top 54335 regulator and looking later the second one towards the middle on the input pin too. We seem to have found some of the same things with voltages . I replaced the first at the top one but got smoke on the second one after fire up. Getting 3.3v on the one I replaced so know that good looking at your findings. I’m waiting for more 54335s to come in to replace the second. Iv tried 5v voltage injection on the coil on that one to see if I can get it to fire up while o wait but it’s not playing ball. It’s drawing about 0.5a though on the 5v when injecting and things are warming up. I have not tested the system management regulator yet and that’s next after the new regs come. Your video was fantastic now looking, I just wish I’d seen it before I was guessing the voltages lol. I’m hoping it’s not fried the P1 soc but it’s hard to tell. I need to start checking the other side of the board where you have the clamping diode and the FET, I don’t believe there is an issue there as I don’t have any shorts but the shielding preventing me getting closer to look. That’s a total PITA. Anyways fantastic video, I have a quick one on the failed repair and some images and stuff on the community page if your Interested. Thanks Mad. .

[@ooSreckoo]

Excellent informative video. On point. Now let's x-ray that PCB and do a teardown of that FPGA layer by layer 🤣

[@LivyuFPV]

ahahahhaha :)

[@kwadkrazy6078]

Watching him solder is so satisfying

[@falkonfpv]

love to see a break down of DJI fpv v2 goggles

[@Rc_Dread]

I have been running my air unit on 8s for about 4 months now with no problems other than forgetting to unplug it

[@spyfpv]

Excellent video! At last a video that actually explains a few aspects of the airunit. Could you also investigate reasons for airunit damaged serial port andpossible fixes? I have 3 of them...

[@HilalAlHarthy]

Thanks for showing us the teardown and telling us about the board design and functions of chips. You are very knowledgeable.

[@mikaelbackstrom]

Love watching you work. Amazed by the experience and knowledge you have. Really enjoyable videos.

[@Mateyhv1]

Wow, didnt expect this video great! Thank you very much Livyu

[@abieazki]

please help, I have an Air Unit with a non-working OSD. Would you happen to know the component that needs replacing/checking similar to the caddx vista solution

[@changeagent228]

Excellent. The minimum input voltage of the 3.3v regulator is 4.5v according to the data sheet. Does the 5v regulator drive the camera? Do you think if we moved those RF modules to a working Air unit we could have four running and double the output power?

[@LivyuFPV]

Well, I will have to study it more. But... don't think so. The camera seems driven by 1.8v. Yes... 4.5-28v input. The rf IC I suspect needs 5v.

[@Orientalmentor]

Electrical engineering is so cool!

[@yngndrw.]

From the RF section, it almost looks like one antenna is used to transmit and the other is used to receive. Would love to see the same for the goggles if you ever get a set of broken goggles sent in.

[@LivyuFPV]

Yeah... it appears to be more inclined to one antenna ;)

[@beqashekiladze8937]

I pushed by mistake led hole beside sd card slot, thought it was for removing sd card 🤦‍♂🤦‍♂, the led doesnt work anymore, but unit works as before. Im worried if I would damage any other parts, that would make malfunction the unit wrong time. Can you suggest what parts could I break along with the red/green led there?

[@blam3329]

I made a new connector for my air unit but I wired it backwards (I was in a hurry). That sent 4S LiPo voltage straight into the ground and SBUS pins. It no longer will bind with goggles, but everything else operates as normal (LED, Bind Button, Software connectivity and file system access). Should I chuck it?

[@giovannitaddei031]

Hi Livyu! have you already tried to disassemble an air unit v2 by caddx to see if they have added the 2.4ghz modules?

[@aarrcchhoonntt]

Thank you! FINALLY someone who realizes the RF shield isn't some magical component and shows the guts underneath! Is anyone aware of a functional block diagram of this thing?

[@FilipRadelic]

2:45 we now know for sure these unpopulated footprints are for 2.4GHz (based on FCC application for V2 goggles/radio), no reference to it yet but I'd guess we will see the same-looking Air Unit with 2 more 2.4G amplifiers 🙂

[@LivyuFPV]

Well I already new why those were there :)

[@johnk8825]

Simply amazing watching you. Thank you

[@cartfpv4610]

Hi! Do you have any idea how to fix broken telemetry on air unit? At Vista it is possible to remove one element to make it working again. Is the similar way to try at air unit?

[@hssnov]

Can you provide me with a datasheet for the dual channel p-type MOSFET

[@redlines2535]

super interesting lot of high tech from dji for fpv

[@tedeix]

@Livyu FPV the video is great even for layman as me. I wonder what would be your thoughts on shorted UART RX with ground? Someone told me that it could be the protection diode, but not sure about it.

[@lutherm116]

going through a similar issue with my air unit not showing vbat. did you ever find more information or a fix by chance?

[@Rcschim]

Great video my friend. I'm so envious of ppl with such talents on the soldering iron. There I have some serious deficiencies ;) DJI stuff is really well built and I'm curious if they already improved it for the upcoming leaked DJI drone. Greets, Mario

[@LivyuFPV]

Thanks Mario! Well the air unit is on par with everything else dji does. But in the same time they have to learn that for fpv the products need to be way more resistant. The air units and vistas can be killed easily by mistake.

[@RHobbyFPV]

Which is the component burned when polarity iversion?

[@j.finesseflights1403]

Thank you my friend, for sharing your knowledge!!

[@christianp_fpv5304]

Hi!!!! I broke up the FC connector into the unit, the problem is that the uart RX pad is broken, I mean the RX video uart, do you know where can I find another point soldering the RX, I mean where is the other point for this RX pad?

[@odedorbach7852]

Thank you Livyu for this detailed teardown. Some of us have issues with OSD disappearing after power spike( perhaps ) . Any thoughts on that please?

[@slowflowfpv5476]

I lost my osd any fix ?

[@rctom1]

@@slowflowfpv5476 I had the same Problem , two diodes between rx and tx broken. coud let it fix and guess , osd working again (-:

[@abieazki]

@@rctom1 please help, where dioda position to remove in Air Unit?

[@rctom1]

@@abieazki sorry i did do it by myself and it was a vista not the big airunit. But the guy told me it was easy to fix only 2 diodes for pennys and its working again. Maybe you ckeck yt for it.

[@TheLarsUrban]

Why are there so many unpopulated footprints? I’ve seen them during repair of my drone too.

[@NunoFlyer]

Nice overview my friend. Have a nice New Year 2021.

[@cj691]

Heyyy! I was looking for exactly this! Excellent!

[@flyingdream777]

Great adventure as usual. I was wondering if you know what IC chip in the Caddx Vista apparently supplied by Texas Instruments is causing shortages of Vista supply. Now apparently DJI will find Chinese supplier?

[@LivyuFPV]

I have no idea :) IT could be the 2 regulators used in the air unit(if they have the same regulator arrangement) I would need to teardown a vista unit and check it.

[@UnrulyRotors]

Nice! Yeah I accidentally flew an air unit on 5S and didn't have any problems

[@froncheek87]

Do you regularly use 5S now on your air unit? Just curious.

[@UnrulyRotors]

@@froncheek87 yes, but I had already ordered BECs so I just put it in there. Better safe than sorry.

[@romanskriliov9360]

Thank you! Great video. Thanks lot.!!!!

[@profaneus]

Thank you for you work, please correct me if i wrong, you found that transient protection circuit what is operating on normal conditions under 22 volts, so the air unit is absolutely compaible with 5s? , i have 5s batteries, and using buck converters from the begining for no reason :D so it is safe with 5s in theory?

[@LivyuFPV]

Yes, exactly!

[@TERBANGFPV]

Can you make a video how to fix no osd problem for air unit? On vista we can fix it by removing the broken tx/rx dioda. But theres no tutorial for the dji air unit about how to find the broken dioda that need to be removed. Thanks

[@mannim.6901]

Hey. Same problem here. I am searching for lots of hours, but found no real solution. TX and RX are shorted with ground and no OSD/Telemetry working. Did you still find a solution? Greez from Germany!

[@TERBANGFPV]

@@mannim.6901 Nope.. still no fix for the air unit

[@michagt3408]

@@mannim.6901 remove the diodes !

[@abieazki]

@@michagt3408 where dioda? please help show pict

[@garamfpv]

좋은정보 고마워 형제🙏🏻🙏🏻😷👌🏻

[@heartpilotOB]

Thanks for the tear down. Any chance you can help solve the non binding issue?

[@LivyuFPV]

please explain

[@heartpilotOB]

@@LivyuFPV I have an air unit which stops binding with the goggles and the radio controller, the bind button does not work anymore. What would be the possible causes? Thanks

[@barabucho]

What's RF chip? - i cant't find datasheet...

[@KAREKINFPV]

What are your thoughts on the sync pulse that regulates the flight distance? I would like to learn more about how that works, could you do a video on that maybe?

[@quadmcjellydrone7909]

Great as always , very interesting.

[@racistpixel1017]

Can you port this for android, like those analog dvr units that connects your android?

[@Stefan_73]

I am not really into FPGAs - would it be possible to identify the FPGA by the BGA layout and the location of the power supplies?

[@LivyuFPV]

could be... but many FPGA products are not public or created by small companies. very very hard work...

[@Stefan_73]

@@LivyuFPV Have a look at the chips of allwinnertech. Their labeling is similar and some have a similar BGA pattern.

[@LivyuFPV]

@@Stefan_73 i know dji worked with them but... still need bootloader. doubt that you can flash it with what ever

[@exoops]

@@LivyuFPV the bootloader is on that micron nand flash

[@RideNFly_FPV]

Thanks Livyu, interesting stuff!

[@shambler01]

I have a unit where I shorted the sbus wire to vbat by accident. Now the telemetry is not working on this unit anymore (osd) do you think it killed something on the chip?. Rx/tx has not been shorted just the sbus. Rest of the unit works fine. Great video by the way!

[@LivyuFPV]

Well, I have another au that has the same issue (no osd working) I checked on the PCB and the RX tx goes straight to the processor with some sort of line protection but... it could kill that section of the processor. Will come back with this info.

[@MrHauf85]

@@LivyuFPV would like too see this video, have an air unit with non funcition OSD, heard that removing the diod on the TX will fix this, I know where it is on the vista but on the AU it is a mystery. Hope you can help me out with a video =)

[@propwashfpv7063]

@@MrHauf85 Having the same issue. Have an air unit with a non-functioning OSD. Did you ever figure out where the diode that needs removing is?

[@MrHauf85]

@@propwashfpv7063 no, guides on the vista are on Facebook, but no info on the AU, hopefully Livyo can help us out

[@shambler01]

@Livyu FPV @InDrone Productions that would be great to know where is this diode on the vista. maybe i can start searching it on the airunit too

[@froncheek87]

Thanks for the info Livyu. One question, do you think we can use 5S safely to the Air Unit?

[@LivyuFPV]

Yes

[@jermadjesty]

Awesome video. Question - what conformal coating do you recommend?

[@LivyuFPV]

I have no idea. I normally use PLASTIK 70

[@AndreasGibhardt]

Hey, did you look underneath the HF shield on the backside of where the IE1000 is.. i would expect to find an ACP transceiver there - can you verify?

[@cedivad]

The IE1000 is the transceiver.

[@AndreasGibhardt]

@@cedivad other devices have both an acp transceiver and up to two ie1000 .. in those designs the acp transceiver is usually hidden on the backside. My current thought is that the acp is for 2.4 and the ie1000s for 5.8

[@cedivad]

​@@AndreasGibhardt Sorry, I never answered. I can confirm the IE1000 chip is the transceiver, there is no ACP transceiver (why should there be? that's what the IE does, IQ goes right into into if & matching RF on/off times if you probe the FPC cable)

[@AndreasGibhardt]

@@cedivad i know that the ie1000 is a transceiver.. only that other hardware from dji allways has the acp in visibly between the leadcore processor and one or two ie1000 so there might be a reason that it is neccesary. the cpu has changed recently and is maybe now able to interface with the transceiver directly. the datalanes to the transceiver run at about 1ghz and i lack the equipment to tap on that.

[@cedivad]

​@@AndreasGibhardt the ie1000 does IQ in from what I probed (that's ~ the same frequency as the RF bandwidth, so 40MHz tops, there is no need for a fancy scope to verify it), and it's been a long time, I might be wrong, but I believe the APC transceiver was doing digital IQ in or some other kind of digital interface and either RF or IQ out (but if there is a ie1000 in the old designs it must have been analog IQ out).

[@fen1x_fpv]

Amazing what you do

[@ak-lk2nq]

Great thanks can i reach about faulty unit ?

[@LivyuFPV]

please Write to me on social media

[@WKfpv]

Very informative as always.

[@causticfpv5857]

But can you fix it? Great video.

[@LivyuFPV]

well if you can find that processor from another air unit... it is possible :)

[@ror-ys3qp]

good job..thanks

[@aronjohnsson9187]

Link for your flux doesn't seem to work? What do you use? 🤔

[@LivyuFPV]

The links were malformed... fixed them.

[@LeadFoot944]

Excellent 🙏

[@johnny4498]

I am thinking about buying a water damaged Air Unit. You think there is a good chance that something else got shorted like a power ic or a cap? Because the chip that died on yours isnt buyable i guess?

[@LivyuFPV]

Yeah... no way!

[@johnny4498]

@@LivyuFPV What do you mean?:) You think there is a chance it's not the main Ic like yours?

[@LivyuFPV]

@@johnny4498 no, i would not buy a water damaged one. The risk of the mcu to be bad is very high!

[@johnny4498]

@@LivyuFPV I would get it for $50 with the camera. That's pretty cheap huh?

[@AngelVlad100]

Recently my drone felt to the snow, when I picked up it I noticed that video doesn’t work anymore. At home checked 9v line on FC and it was dead(0V). Then I connected 4s lipo directly to the air unit, It’s worked fine. Bought new FC, connected, and again fried. Checked air unit resistance between + and - it was 0.01 Ohm so I decided to teardown air unit, visually didn’t find anything suspicious. So I was a little angry and decided to check what if I connect it to 6s, It was fine. Then just to ensure that it’s still dead I found that resistance is... 1720 now. MAGIC!! Checked current at 10V bec from esc - 0.8A at start, then dropped to 0.45A. Apparently by connecting 6s I fried smth like dead filtering capacitor.

[@mas2ery]

Hey? Thats a MEMS Mic left of the IE1000 right!?

[@LivyuFPV]

nope, that's a crystal used to generate the RF ic clock.

[@LivyuFPV]

PS: i saw no mic

[@Nikita-zd1gc]

@@LivyuFPV so original cam have mic( where else?), and they in theory can do live audio on both vista and air unit)

[@spikester]

@@Nikita-zd1gc The mic looks to be the square 434 part below the P1 chip, if I were to guess there is a hole for it on the opposite side of the board. At least it doesn't appear to be a typical ceramic base oscillator.

[@Switch180fpv]

Very interesting thank you

[@ken-kamm]

Fascinating. Thanks.

[@serkoner1]

Thanks 👍

[@HayBeseret]

Thanks you

[@gmivisualsjason3729]

Excellent.....

[@FilipRadelic]

Thanks Daryl and Lyviu!

[@FilipRadelic]

I always enjoy your teardown and repair videos, but this one was particularly interesting. Some really cool things we learned about the Air Unit here. Btw have you found a Vista to tear down or still need one? Guessing it’s veeery similar, but would be interesting to see the difference up close.

[@changeagent228]

+1 to see Vista comparison.

[@LivyuFPV]

@@FilipRadelic I still need one, preferably a dead one. Thanks!

[@FilipRadelic]

@@LivyuFPV shoot me your address to [e-mail] - I did something really stupid to one 😅

[@B3NSipodtouch]

Ur a boss

[@DronePlayground]

😱👍👀🇭🇷