Stan Larroque's Blog

Author: Stan

  • Prototyping any stereo camera with StereoCam

    This post is for any person in AR/VR/drones and beyond who want to quickly prototype with stereo cameras.

    Our StereoCam prototyping platform

    At Lynx, we are big on passthrough for Mixed Reality and thus we always had a need to test various setup of stereo cameras. We even built a passthrough MR headset with 140dB+ HDR cameras (probably not the HDR you think about).

    In order to test various lenses and sensors when tinkering future HMD configurations, I built as a weekend project a prototyping platform for the team where the goal was to be as simple and effective as possible to have quick results.

    The result is a platform built on top of the latest Raspberry Pi 5. The Raspberry Pi 5 has 2 dedicated MIPI ports, and all the bells and whistles you can expect from a small yet powerful ARM computer. There is even a 16Go RAM version now, pretty cool.

    What you’ll need to assemble this:

    The casing is separated in 3 volumes (CamHolder, Case, Lid). You can 3D print these with standard PLA very easily.

    CamHolderDownload
    CaseDownload
    LidDownload

    The CamHolder was designed to hold the High Quality Camera from Raspberry Pi. It is a camera module based on a high-res Sony IMX477 sensor. So you can add two of these to the BOM.

    The case is designed to hold the Raspberry Pi 5 and its active cooling add-on. If you’re just streaming the cameras over the network to do processing somewhere else, then the whole system should only consume 5-6W, which could be fine without a cooler. Otherwise the active cooler is greatly encouraged.

    The case supports all RPi interfaces and its active cooler.

    To connect the MIPI cameras to the Raspberry Pi, you’ll need this kind of FPC: https://www.digikey.fr/fr/products/detail/raspberry-pi/SC1128/21658272. It also exists in 300mm and 500mm length.

    You also need to pick the right lens for your camera. Here is a vendor with a conveniant tool to pick the right FOV based on your resolution requirements.

    In Lynx use-case, we dump the RAW frames over the network so we can process them later and on a more powerful computer. We use the Raspberry Pi strictly as a “networked capture card”. The board is connected over Ethernet and we can start streaming the cameras with simple commands thanks to the Raspberry Pi incredible software support for cameras. You should find there your preferred ffmpeg/streaming command lines and if you don’t, you can always dig deeper with libcamera.

    Now you have in your hands a very capable stereo camera setup that can do a little bit off onboard processing (not any heavy AI stuff, but OpenCV distortion correction etc is largely feasible). You could even mount it as a payload on a drone and do some cool stereo FPV!

  • The Next Step (2/2)

    Android XR banner featured on Google announcement’s post

    Finally, Google went public with Android XR, after years of working on this new paradigm for the Android ecosystem.

    All standalone XR headsets on the market are running currently with their own customized version of AOSP, the open-source part of what people know as “Android”. On top of that, Google just released developer tools, optimizations, perception algorithms and various other software solutions all dedicated to XR. Which I believe is great news for the overall XR market.

    Below is a Road To VR article showcasing some projects who were onboarded with Android XR. Lynx is very much part of this group.

    Lynx Confirms Android XR For Next Headset, Sony & XREAL Also On-board for Google’s OS
    Ziad Asghar, Qualcomm SVP of XR during the Google announcement event in NYC.

    The announcement (video here) was centered mostly around the high-end MR Samsung headset. I have to say I was quite amazed by the demo and the device itself. Think of it as the Vision Pro but without the front display and with a more rigid strap. The passthrough was pleasant, mostly because of the low-latency of the micro-oleds panels (compared to a LCD display, they don’t need to wait for the full frame to be rendered to display an image). The MTF of the lenses was quite low in periphery for a pancake lens, but the units they were showing to the press are “early units” and some changes are to be expected.

    Now for Lynx, it’s great to be able to talk a bit more about this collaboration with Google and Qualcomm. We are adopting Android XR as an OS compatible with our future headsets. The Lynx-R1 will not be compatible with AXR, but I expect all our future products to be AXR-compatible.

    The hardware team is working hard on a new product, and you will hear more later in 2025. The software team is still doing R&D and OS work on the side of our AXR integration, for specific customers like in Defense or the medical field, and for some users who will still want something different.

    Lynx is basically doing in XR the opposite of Blackberry in the mobile market. Blackberry was killed by the iPhone, but it was also mostly killed by refusing to adopt Android and thus lacked an ecosystem on the long-run. On our end, we are aligning Lynx with a great partner and future ecosystem like Android XR, while also having our own solution for some specific needs.

    Edit (21/12/24): for those of you who understand French, here is an interview I gave on French television from New York reacting to the Android XR event.

  • The Next Step (1/2)

    Tomorrow, exciting news will occur for everyone in the AR/VR (still small) world. Lynx is involved and some pieces of something we’ve been working on for a few months will be revealed.

    I can’t talk about anything that will occur tomorrow or the partners involved, but I expect a round of tech news to cover it extensively.

    No matter what will happen and what you can learn/speculate from it, these are my words:

    Lynx is still committed to the same mission: unlock the best Mixed Reality experiences with amazing devices and OS-level integration for spatial computing.

    We are not acquired, nor did a new fundraising. The team is still in place, and still working on exciting new projects and supporting the existing Lynx-R1.

    With the latest hardware, optics, and perception sensors and algorithms available now, Mixed Reality is at a level I could only dream about when I started Lynx.

    There are more software engineers working at Lynx than hardware engineers (approx. 2/3 SW, 1/3 HW), and they are still working on our OS based on AOSP, from drivers and kernel patches all the way up to the application layer and OpenXR SDK.

    For the R1, we are shipping now the last hundreds of devices going to our community (you should see the shipping emails before the end of this week), and will refund the few who asked, as previously declared. We needed a bit more time than anticipated after this summer as the company faced some challenges in 2023 and 2024.

    Now for what is coming ahead, the team and I can only contain our excitement for now, but we believe Lynx has now passed a crucial inflection point, both in resources/engineering available and means to really build in quality and quantity at the level of our initial ambition.
    Please remember that our total budget for the last 4 years is approximately 4 hours of budget at Meta (1B$/month, divided by 720 hours was our yearly burn rate lol).

    I can’t wait to share more early next week with you all. Expect a longer blog post.

    Stan

    _________

    Unrelated note: I’m using this post to also signal that I probably won’t be posting on Twitter/X anymore, I generally don’t use social media and grew tired of it all, and I’ll just use this website more if I need to share things.

    Unrelated note for the French here (no subtitles available for now): I talked about AR/VR in this video last month, mainly reacting to Meta Orion.

    I’ll be speaking at SPIE AR/VR/MR conference at the end of January.

  • I don’t eat added sugar

    I’m about to turn 30 in 2024 and these last two years, I noticed I started to gain some weight.

    I was always thin (almost skinny) for most of my life, and suddenly I gained a few kilos, and it started to reflect on my face. I really couldn’t stand it so I decided to act.

    It was obvious that with Lynx, I was enduring some stress, and working late at night. When you work late at night, often focusing for a long time on one activity, you eat sugar to stay awake. When you’re stressed, you also tend to eat sweet things.

    I saw a photo of myself at a friend’s wedding and I was disgusted. So immediately, the thing I did was to just stop eating added sugar. I realized I almost stopped eating because sugar was in everything I ate. The only sugar I have is through fruits.

    I did nothing else, and lost 6 kilos in two months (from end of July to early October). From 74 to 68kg. During August, I also did some research to check if I was doing the right thing (and not slowly dying).

    Mid-may 2023 vs early October 2023

    Mid-may 2023 vs early October 2023, face has less border-radius…

    There is actually a lot of people, especially in the US, that are discussing this matter, and YES, eating sugar is most of the problem.

    You can do your own research on this topic, there are plenty of resources online, but I will share a very good talk about it (really worth your time):

    This video contains the essence of what’s wrong in the relationship we have with sugar and especially added-sugar (glucose-fructose).

    What I also tried (and still doing) but the impact is not necessarly on weight:

    • Buying an alarm clock and having your phone not in the bedroom
    • Eating better
    • Decent sleep hours

    I also remember that we still all die at the end :-), but I want to age in a better shape than the trajectory I was on, that’s all.

  • My personal setup

    A short article about what I use to manage my digital life.

    Computer

    It took me some time to find the right setup for me. I tried Mac, Windows and Linux and still own machines with these OS and my daily driver is finally Ubuntu 22.04. I mainly use a Dell XPS 13 running Ubuntu 22.04.

    It allows me to take calls from Webex/Google Meet/Teams/Zoom/Skype etc, and use professional software like the Jetbrains suite, Unity3D and Fusion360. It’s also great because most of my work on server-side stuff is also running on Ubuntu server or Debian.

    For the webcam I’m using OBS with my iPhone (modern smartphones have great cameras, might as well be useful with the computer as well?)

    I have a small Windows 10 virtual machine that I only use to run iTunes to backup my phone since I own an iPhone but don’t use iCloud.

    My browsing experience is simply Firefox with uBlock Origin.

    Phone

    I use an iPhone 12 13 mini. I owned an iPhone SE (2016) before for some years. I like being able to use it with only one hand, and having a smaller screen incentivize me to use it less (at least that’s my belief). I’m not a big user of my smartphone because I don’t want to be too dependent. To give you an idea, this is my home (and only) screen:

    Yep, not much.

    I only have notifications enabled for SMS/Signal and Gmail (the last one doesn’t have sound/vibration).

    I don’t have accounts for Facebook/Whatsapp/Snap/TikTok etc… for Linkedin and Twitter I use Safari or my desktop as the apps consume too much battery and are generally doing more tracking than the mobile web experience. My background is black because the phone display is OLED-based so it consumes less battery.

    The only thing I don’t like on my phone is Signal not providing a good backup system for iOS.

    I highly recommend the “DS File” app if you have a Synology server, see next paragraph. I use it to backup my photo as well as having my music and some important files (ID, passport scan etc) at hand. Also thank God for Adguard.

    Servers

    I own a Synology DS220+ at home that I use for:

    • Backing up my computer and email, photos, files… as well as some of my family members data
    • Backing up my phone (DS File for photo backup, and for everything else the backup file from iTunes)
    • Hosting this website
    • a VPN when I’m abroad or when I need
    • My addressbook server

    As it’s quite sensitive, it’s using the highest security possible. It also syncs weekly with a distant cloud in an encrypted manner, so if my house burns down or someone breaks in and steals the server (useless without the keys to decrypt content on disks of course), I still have a backup. I highly recommend this product.

    I also operate some servers, mainly rented from OVH (<3).

    HMDs

    Of course I own various AR & VR HMDs, and at Lynx we have most of what’s on the market.

  • Lynx Original Hardware Team

    From left to right, Hugo Artarit, Laurent Chabin, Stan Larroque, Didier Lasne, Corentin Lefebvre, Etienne Denoly

    As I’m preparing a Lynx press release for Monday, we took some pictures at the office.

    This is the original hardware team at Lynx that brought the Lynx R-1 to life.

    From left to right:

    • Hugo Artarit, industrial designer
    • Laurent Chabin, electrical engineer
    • Stan Larroque, group leader
    • Didier Lasne, mechanical engineer
    • Corentin Lefebvre, optical engineer
    • Etienne Denoly, industrial designer

    Of course, not in the picture are people working at Compal, Qualcomm, Limbak and Ultraleap that helped on the work related to the hardware at different points in the development.

    I’m saving this photo here because this is probably the last time we’ll work together in this setup because Lynx is growing fast and we’re hiring a lot, and I’m very proud that we achieved with such low resources.

    I’ll do another photo with the software team of course!

    Here is the photo of the full Lynx team that created Lynx R-1:

    Lynx Team November 2021 in the Paris Office.
    Left to right: Jean-Marie Vaidie, Didier Lasne, Cedric Morel Francoz, Marc Piuzzi, Etienne Denoly, Hugo Artarit, Laurent Chabin, Stephane Amoa, Stan Larroque, Guillaume Le Fer, Chouki Hadri, Geoffrey Marhuenda. Missing in the picture: Corentin Lefebvre, Guillaume Chevalier.

    If you want to join this team, contact me.

  • Throwback: the first visual demo of Lynx

    This video clip is the first visual demo of my Mixed Reality system, it was not named Lynx, and it wasn’t even named at all! It was featuring a simple helicopter model that land on a surface in front of you.

    The viewer was an Oculus DK2 and the program was running in Javascript thanks to WebVR on Firefox. There already was two cameras for correct stereoscopic view, fetched with the getUserMedia API.

    It’s funny because at this time, it feels like I opted for the worst stack for the proof-of-concept: it was running on a Mac and in a browser, the whole thing written in javascript. The definition of the cameras was awful, no distortion was corrected, it was all fixed with duct tape and cardboard.

    But it worked! It was in September 2016, I still have the source code. And I’m really proud of the version we have today.

  • Going to Laponia

    We decided with my brother to hike together in an unusual place : Laponia, and more precisely at the very North of Sweden.

    We landed in Kiruna, and hitchhiked to Nikkaluokta, the start of our hike. The goal was to reach Abisko from Nikkaluokta by using a portion of the Kungsleden (the king’s road, one of the most famous trails in Sweden) Wikipedia.

    Here you will find the exact path we used, and you can google “Abisko – Nikkaluokta” if you want to make the same trip. We made it in four days, but it is typically a walk of 6-7 days or more if you want to relax.

    Our path

    Here are some photos along the way, we had a nice weather. Only trick: there is no night time, it’s always “day” but you can feel when the Sun goes behind the mountains. We had an average of 13°C with 75% of humidity, very good conditions to hike.

    We saw some rabbits and reindeers in packs, but it is mostly a desertic and hostile place. In two words : magnificent and quiet.

  • Surviving the Hacker News “hug of death”

    A quick article to mention that one of my articles on the DNS requests made by iPhones made the front page of Hacker News for a few hours. (and it got a lot of interesting comments!)

    When your post gets on the front page, there is what we call in the community the “HN hug of death”. It describes the huge traffic you will see on the URL you shared, and sometimes your site becomes unresponsive because the server is bloated.

    To be totally honest, I didn’t suffer from it because this blog is running with a very tiny CMS (almost a static website), the server is not a small VM and the front end is not bloated with dozens of requests.

    I got 10 114 unique visitors to the blog post from Hacker News on that day, so with a well-optimized website, everything should be fine!

  • High number of DNS requests made by iOS devices

    I run a simple ad blocker based on AlgoVPN. It is a simple adblocker for iOS devices. It blocks requests at the DNS level, so it is network-wide and thus very efficient.

    The connections are strictly anonymous and very secure (the code is here), but I anonymously log the DNS requests. It is a way of monitoring the usages of my servers.

    When I tested the service on my device, I discovered that iOS communicated non-stop with Apple servers. I thought it was linked to the Push services, but I looked into the logs and here are the concerned domains that are iOS-related:

    apple.com
icloud.com
akamaiedge.net
akamadns.net
apple-dns.net
akamai.net
akadns.net
cdn-apple.com
aaplimg.com

    Here is a screenshot showing the unexpected number of requests your phone makes. Notice the activity between 3AM and 5AM (I swear I was sleeping haha).

    I haven’t tried on Android devices, but it should be interesting as well. Another experiment would be to block these domains and see the impact on your battery life 😉

    UPDATE:

    Here is what it looks like with more devices. Observe the difference of requests between the two graphs.

    Here is a breakdown of all concerned hosts in a light csv file.

    Read more on the Hacker News discussion.