TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC
  1. TMC is currently READ ONLY.
    Click here for more info.

How is your rear camera after MCU1 to MCU2 upgade (dark?)

Discussion in 'Model S' started by Battpower, Apr 28, 2020.

  1. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    #181 appleguru, Feb 4, 2021
    Last edited: Feb 4, 2021
    To follow up on this: on MCU1, the backup camera feed is overlaid on the screen directly so that the (slow) Tegra doesn't need to decode anything.

    The Model S/X use Maxim 9259/9260 SERDES to essentially send the "raw" CMOS signal from the camera sensor to your MCU. From there, an FPGA on MCU1 essentially drops the pixels directly into the image feed coming from the Tegra into the "correct" location on the screen .

    I wonder if MCU2 is instead taking an encoded (i.e, lossilly compressed with something like H264) feed from the APE? (It definitely is for the non-backup camera feeds, as those physically only go to the APE). Perhaps they're using the "wrong" encoding settings (settings optimized for other cameras) and applying them to the MS feed?

    A good test: Someone with AP1 (or no AP) that upgraded to MCU2... would be interesting to see if they have different (better) results with their backup camera image in low light...

    [edit] just got confirmation that apparently the backup cam still works when directly connected to MCU bypassing APE, so that debunks that theory... really at a loss for a technical explanation for why the feed is so much darker on mcu2...[/edit]
     
    • Informative x 2
    • Like x 1
  2. Battpower

    Battpower Supporting Member

    Joined:
    Oct 10, 2019
    Messages:
    1,950
    Location:
    Uk
    So if the cameras are not replaced as part of an MCU 1 to 2 upgrade then whatever is different is internal to the MCU.

    If MCU 1 just produces a video overlay not processed by the Tegra then however that video feed is processed produces a very similar image to the other three video feeds used for Tesla cam / reversing cam.

    I have read / been told by a variety of sources that a) dark MCU 2 image is due to image rendering and b) the video path for rear cam is different on MCU 2 (connects to different bus).

    @AWDtsla pointed out 'black crushing' effect, which I don't think contradicts this:

    I haven't tried messing with levels on a recorded clip, but I doubt that increasing brightness will result in same image as you get from MCU 1 reversing cam.
     
  3. kdday

    kdday Active Member

    Joined:
    Oct 29, 2016
    Messages:
    1,131
    Location:
    AZ
    The cabling path for backup camera is exactly the same between mcu1 and mcu2. Mcu2 has a different FPGA chip that for whatever reason renders the backup camera feed differently on mcu2 (darker).
     
    • Informative x 1
  4. Battpower

    Battpower Supporting Member

    Joined:
    Oct 10, 2019
    Messages:
    1,950
    Location:
    Uk
    I understood physical connection was the same. Does anyone know anything about that chip? Does it do the video processing then put a digital stream onto a data bus?

    Begs the question if it is fixable if the processing is hard coded on that chip.

    And.... any clues as to why the design would change for something that on the face of it performs worse?

    Although you would think there must be software control of settings, but if it's that easy, why isn't it getting fixed?
     
  5. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    Doing a bit of digging into this...

    On MCU1 the path from camera to the screen is (roughly; the CMOS sensor I think is different now but that doesn't really matter):

    Inside the backup camera module: Omnivsion OV10630 CMOS sensor -> Maxim 9259 serializer, like this:
    Camera.jpg

    From the backup camera -> Rosenberger HSD/LEONI Dacar 535 cable.

    For AP1 or pre-ap cars, that cable plugs directly into the blue HSD connector on the back of the MCU.

    For AP2+ cars, that feed goes to the APE first, and then to the MCU. For AP HW2.5 and HW3 ("FSD computer"), there is a daughterboard that looks like this:
    daughterboard-jpg.png

    That board passes the serialized camera feed through to the MCU via the black connector, but also taps it off for the APE. It deserializes it with a Maxim 9260 and feeds it into a TI DS90UB913A-Q, which re-serializes it as FPD-Link III on the purple connector. A cable connects from the purple connector here to the purple connector on the APE board, where it gets handled the same as the backup camera feed on the Model 3/Y (deserialized via a DS90UB954-Q on the APE).

    The MCU provides 12V to the backup camera via two pins on its blue HSD connector. The other two pins are for the serialized feed from the camera.

    Internal to the MCU, for MCU1, it looks like this:

    Blue HSD connector on the back of the MCU -> Maxim MAX9260 deserializer -> Altera (Now Intel) Cyclone IV EP4CE40 FPGA -> LVDS display connector -> LCD screen.
    mcu1.jpg


    Internal to the MCU, for MCU2, it looks like this:

    Blue HSD connector on the back of the MCU -> Maxim MAX9260 deserializer -> Toshiba TC358746AXBG

    toshiba.jpg

    That Toshiba chip converts the backup camera sensor's raw parallel "DVP" signal into a MIPI CSI-2 signal, which I assume the Intel Atom SoC has an input for (but I haven't sorted out that connection yet).

    It does *not* overlay the feed directly on the screen / into the LVDS feed like the MCU1 does. The screen on the MCU2 shares the same LVDS interface, but uses an Analogix ANX1122 eDP to LVDS chip to connect the Intel SoC.

    analogix.jpg
     
    • Informative x 6
    • Helpful x 2
  6. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    What (I think) we know: For all non-backup cameras, the APE decodes the FPD-Link III signal from the camera(s) and encodes them as H264 streams sent over ethernet to the MCU. We do not know if it also does this for the backup feed, but it certainly could for AP2+ vehicles. H264 is lossy, and can certainly result in a loss of color information and/or dynamic range.

    The raw parallel backup camera feed is converted to MIPI CSI-2 and sent to the MCU for further processing. At this stage the data available is still "lossless" / raw, so there shouldn't be any loss of dynamic range or color information. But we don't (yet) know what happens in software from there, or if there is some other hardware in the chain before it gets ingested that I haven't found yet.

    I still would love for someone that did an MCU2 upgrade with AP1 or pre-ap to share some video/images of the backup camera feed at night. Curious to see if it is "smooth" like the MCU1 or "stuttery" like the MCU2, and also curious to see if there is any difference in image brightness/nighttime fidelity.
     
    • Like x 1
  7. Nick70d

    Nick70d Member

    Joined:
    Jan 20, 2019
    Messages:
    132
    Location:
    St.louis
    My is AP1 with mcu2 , back up camera is dark, very dark compare to mcu1.
     
    • Like x 1
  8. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    Ok, took a preliminary look at the software side of things to try and figure out what is going on here.

    The Intel SoC indeed is capturing the CSI-2 feed directly. Tesla uses their drivers (intel/intel-camera-drivers) to make the feed available as a sysfs device at /sys/bus/media/devices/media0

    From there, they use Video4Linux (v4l2) to configure a capture pipeline with media-ctl, capturing the pixel data as raw YUYV (YUV 4:2:2).

    Presumably this is then displayed "directly" in their QtCar application when the user pulls up the backup camera. The repeater cams in the backup camera view are coming in via H264 UDP streams from the APE.

    Interestingly, the video feed for the backup camera used with the dashcam/sentry feature *is* actually streamed in over Ethernet from the APE, (UDP/H264), and is muxed to an mp4 file using GStreamer.

    So, presumably Tesla just needs to configure the exposure settings on their v4l2 video pipeline to completely fix this "too dark" issue...
     
    • Informative x 7
  9. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    Thanks for the confirmation. Looking at the software it does look like they're using the same code for displaying the backup camera for all model s/x regardless of AP type... so once they fix it it should be fixed for all. (Here's to hoping they actually fix it)
     
    • Like x 3
  10. random155

    random155 Member

    Joined:
    Mar 18, 2019
    Messages:
    872
    Location:
    NJ
    Potential problem? Is there a way for them to deploy a fix for this that will not mess up MCU1 back up cameras with already good imaging? Could that be the hold up?
     
  11. beatle

    beatle Member

    Joined:
    Aug 31, 2019
    Messages:
    966
    Location:
    Springfield, VA
    MCU1 and 2 use different firmware, so I don't see why they can't apply a fix to MCU2 and leave MCU1 alone.
     
    • Like x 1
  12. Snowstorm

    Snowstorm Active Member

    Joined:
    Dec 8, 2016
    Messages:
    1,488
    Location:
    Ontario Canada
    Can you send this info over to Tesla for their consideration? A deal backup camera isn’t a show stopper but is disappointing knowing how good it used to be.
     
    • Like x 1
  13. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    I’m sure their engineering team already knows everything I posted ;-)

    I’m not a video4linux expert, but I’d love for anyone that is to chime in. It’s not immediately clear what controls the intel driver(s) support, though exposure/brightness does seem pretty basic. Is worth bearing in mind that these are all pretty low level systems though, designed and optimized to run in hardware. So if the hardware doesn’t support the adjustment, then we might be SOL without using a higher level library for image manipulation (which would in turn cost valuable CPU/GPU cycles and possibly introduce a slight undesirable video lag)
     
  14. Nick70d

    Nick70d Member

    Joined:
    Jan 20, 2019
    Messages:
    132
    Location:
    St.louis
    I will forward this to the feedback after upgrade email , hope they fix it.
     
  15. vthreee

    vthreee Member

    Joined:
    Aug 20, 2017
    Messages:
    70
    Location:
    Sugar Land
    extremely dark! lol my street has no lights on it, im in a semi rural area, and its kinda annoying.. anyone got a fix?
     
  16. doctorwho

    doctorwho Active Member

    Joined:
    Jan 3, 2014
    Messages:
    1,131
    Location:
    Eurobin, Victoria. Australia
    I've had the problem intermittently since my MCU2 upgrade. It isn't consistent.
     
  17. Akikiki

    Akikiki A'-Lo-HA ! y'all

    Joined:
    Nov 26, 2012
    Messages:
    6,275
    Location:
    Kaneohe, HI
    Well, I do not mean to disagree with anyone else opinion on the bright or darkness of their backup camera. But I am beginning to wonder if its not also perspective for - me mainly. I drove MCU1 cars for 8 years. Now its MCU2. I can't go back and compare it to my most recent former MCU1. I simply didn't pay much attention to how bright or dark it was.

    Trying to create the same issue that people describe, I've sit in my garage at night with all the doors closed and all the lights off including the car's. Can't see anything from the rear camera. Hmm, maybe I am not supposed to? With parking lights on, with foot on brake, and with car in reverse (brakes on and brakes off) I can see - even in the garage.

    If you go back and look (I think its this thread) I did a brief - easy test using the newest 2020/21 model rear camera on my '17 MCU2. Used it for those same "views". Nothing was different. I am of the opinion now, if there's an issue, the camera version doesn't make a difference. We have now confirmed from 2019 owners that their image is dark too. So MCU2 upgraded or factory MCU2 seems to be the same.

    @appleguru has done some very thorough tracing of the camera issue and told us about it. I've made taken my best shot by trying a newer camera. I can put up "the problem" because the worse is when its completely dark no light anywhere and I simply don't drive without lights. So, with taillights, brake lights and/or backup lights, I can see well enough not to worry about this any more.
     
    • Like x 1
  18. Cybertrk

    Cybertrk Member

    Joined:
    Dec 11, 2019
    Messages:
    6
    Location:
    Ashburn, VA
    I read on one of the reddit forums that a service center claimed 2021.4 or 2021.8 will fix this issue. I haven't received 2021.4 yet, can someone else who has confirm whether this issue got addressed?
     
  19. Akikiki

    Akikiki A'-Lo-HA ! y'all

    Joined:
    Nov 26, 2012
    Messages:
    6,275
    Location:
    Kaneohe, HI
    @Cybertrk,

    I got 2021.4.2 last night and installed it. Since you mentioned that you were told this fixed the issue, I thought I would take some pictures.
    Bottom line, I don't think it mattered. Here's three.

    This picture is with no lights. I got in the car, pulled up the camera didn't turn the headlights on. Garage is dark and doors are closed.

    You be the judge. Did 4.2 help?

    No lights.jpg

    This picture is with my foot on the brake. Most lighting is coming from reflection of headlights from the white garage door.

    Foot on Brake.jpg

    Final picture. Foot off the brake. Car in Reverse (you can see the marker lines) and headlights still on.

    Reverse.jpg
     
    • Informative x 1
  20. appleguru

    appleguru Member

    Joined:
    Mar 15, 2017
    Messages:
    952
    Location:
    US
    hard to say without before/after... but maybe. Looks like you can see the sensor artifacts in your first shot, which implies to me that you indeed can see way more than I can at the moment in low light.

    Nobody expects the sensor to work with *no* light, but your photos provide some evidence that things are actually working better now. I’ll try and take some before / after shots in a semi controlled environment once I get the update staged.
     
    • Like x 1

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC