The DJI P1 and S1 FPV Chipset – It’s Not All That

With all the talk on what chipset is Fat Shark and Walksnail using in the new Avatar / Dominator FPV Goggles and system today, I have been talking with and collating a lot of the information from some of the fantastic guys who are really digging into the DJI system. To try and demystify things I have put this together based on the information provided to try and show that what DJI is doing with their hardware specifically Is really nothing special.

DJI originally used a Leadcore chipset specifically the LC1860 on their older Ocusync based drone models including the Ocusync Air FPV system. Ocusync was first seen on the Mavic Pro as a replacement for the Lightbridge system that DJI had previously used. Its big difference was it’s an SDR based of off the shelf hardware rather than hardware-based radio. After Ocusync’s introduction, It was used on a Leadcore chipset right up to the Mavic 2 Pro.

Just to explain about Leadcore, they are a Chinese foundry-less chip designer that makes SOC for tablets, phones and smart devices. The Leadcore SOC is all in one with both the system processors and RF Modems on a single chip. They are not widely used and also not particularly good ones either as what DJI was using was made in 2017 and not exactly cutting edge, it’s not up there with snapdragon, Apple A-series etc. The specific chipset DJI was using is the LC1860.

The P1 SOC appeared for the first time in the Mavic 2 Pro B remote and replaced the Leadcore chip, the craft continued to ship with the Leadcore as I understand it. Overall nothing from Ocusync’s performance point of view changed other than it is DJI first use of the P1 in its Ocusync 2 system, It’s basically like for like compatible on the Ocusync front.

The P1 then next appeared in the new FPV system and then subsequently in all their consumer drones right up to the Mavic 3 and we almost defiantly in the Mini 3 as well.

The P1 appears to be a customised version of that initial Leadcore SOC. All of the extra “bits” that were not needed for DJI application was removed and it was tweaked to make it more specific. Again nothing groundbreaking just a custom Asic solution rather than the off the shelf option.

Inside the P1 (Pigeon) is pretty much a copy of Leadcore’s architecture. It’s got two big Cortex-A7 cores, some small ones, the dsp ect and a few other bits and a bucket load of on-die RAM. They are basically using the same CPU core + DSP setup as the Leadcore chipset and it’s likely running custom software for their LTE based OcuSync and this is what’s making the difference. The P1 first big core runs Linux, 1 runs the rtos in combination with the dsp-s. The small cores are used for trust zone os and other things. It also has very limited capabilities for video as it’s mostly an encoder, decoder, MIPI input and HDMI output, a multi-phy LTE. This is why it offloads camera control ect to the AP1302 DSP on the 120fps models as there is nothing onboard to do it.

There is also a S1 (Sparrow) variant that only does RF side of things and uses Cortex-M instead of Cortex-A for the application processor and communication processor and is used in the newer remotes like RC231 etc where the video is offloaded to another SOC such as the Eagle H3 chipset.

While it’s clear the P1 is extremely capable based on the actual performance we have seen with it in the various Ocusync based systems it remains the case nothing in the P1 is latest tech or even that secret or impressive. Its Arm cores, SDR, RAM, MIPI, HDMI and USB interface. There are far more powerful and more capable chipsets out there today that could be used for instance to do the same thing. There are some newer ones designed for the 5G market that will be easily be more powerful that this 2017 based chipset DJI is using.

So could someone copy DJI Chipset or Ocusync.?

So yes we could absolutely see it happening that others start to bring something very similar to the market. Copying the Asic is not simple but not impossible. However, Ocusyncs on the other hand is an SDR. It’s not totally hardware-specific and its code could be adapted to run on Leadcore again or other hardware.

The barrier right now is more than anything the cost of these chipsets. DJI going the custom Asic means they could reduce the unnecessary parts of the die, and improve yields and cost but that goes out the window once these other chipsets really start to get traction. At the moment many of these new ones are simply too expensive and have not gained adoption in the mobile space yet. That takes a little time and the chip shortage has not helped.

What I want to stress is while DJI clearly has some special sauce in their software the hardware is nothing magical that can’t be replicated or replaced with enough time and effort. Up to now it simply may not have been viable. Based on all of this it’s my opinion remains the same as I said in my video that DJI is extremely unlikely to just licence this out and allow 3rd parties to sell the P1 under a multitude of different brands and names. While we know they have partnered with others over the FPV system it’s been widely believed and accepted that is actually DJI still making the hardware and others are simply branding it allowing DJI to retain control. The P1 chipset is very much DJI current tech and is still used in the new Mavic 3 and RC Pro. There is nothing in the current FPV system that’s “old” tech and not wanted now by DJI.

Also, any discussion of CaddX being involved in creating DJI FPV core system is not based in really IMO. it’s like asking a carpenter to build a rocket to Mars. This is well beyond them and likely DJI tbh. Chances are the P1 was designed by Leadcore or a similar design house to spec form IP blocks or one of the other design houses in China based on LC on behalf of DJI.

Right now it remains the case we don’t know what Walksnail and Fatshark are doing but please don’t think a copy system is not possible as DJI have had this out for close to 3 years now. Copying and cloning is inevitable I want to say a massive thanks to the work Joonas, Bri3D and all of the amazing guys who have helped demystify this have done so we all underhand more about how our systems work.