My day-two review of the Comma 3X Self Driving Camera for Gen1 R1- Promising, but not ready for laymen.

[wsaHarem]

Anyone in Austin, TX that wants to collaborate on an install?

I’m outside Austin in Leander. I’ve sort-of installed it, but my ACC+ computer went offline, so waiting on Rivian to hopefully reset it on Thursday. If Rivian can fix my ACC+, then I’ll jump back on my install.
I’ve done a magmount install and done the Lukas harness without the upgrade yet. I would redo the harness and run the cables to complete the install. Per Gerry, he suggests starting with the default OP config to get used to it. Open to collaborate.

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[DuoRivians]

There’s no f-ing way I’m trusting Comma. I’m happy if it remains an “enthusiast’s” thing and never full consumer product.

 

[Lon12]

Here is the product I'm referring to today: https://comma.ai/

Support for Rivian on the Comma 3X is in active development, but the default software does officially support it. I have 3 hours of drive time on the default software of this device.

What it does / doesn't do
The camera has the following primary capabilities out of the box with default software:

• Drive-line detection
• Lane Centering
• Auto Steer
• Hands free driving on any road (not just pre-mapped roads)
• Lane changes (started by the driver when clear, and the system will handle the rest)
• Dashcam

Overall the system is designed to be an improved version of Driver+, but with geographic restrictions on where it can be enabled. I've enabled it on residential streets at 25 MPH.

Drive-line detection
The Comma 3x is leaps and bounds ahead of the drive-line detection of Driver+.

One thing I've noticed is that Rivian's default drive-line detection is not capable at detecting S curves. The first bend of and S curve is all that shows up, and then when you start to go into the second bend of an S curve, the drive-line swings wildly to the other side.

However it looks to me like the Comma 3X is capable of detecting complex lane shapes and bends, and plotting a smooth drive line through it.

Here's a diagram I made in paint to maybe explain what I mean:

I have looked at the drive line on very difficult roads, and my confidence is through the roof that the drive line is being generated correctly, and robustly.

Lane Centering
In general, the lane centering is extremely comfortable with no rubber banding. I've noticed that the system doesn't try to firmly keep you in the center of the lane, but it does keep you going straight. By that I mean that you might be hugging the left lane line, perfectly centered, or hugging the right lane line. But no matter where you are, you aren't bouncing between other sections of your lane.

The Comma 3X allows driver steering intervention without disengagement. So, if you want to reposition yourself in the lane, you can. Semi getting to close on your right? You can hug the left lane line by turning the steering wheel slightly, and the system will take back over.

Auto-Steering
The auto-steering is unfortunately perhaps the weakest part of the Comma 3X. This is due to how steering wheel torque is currently being signaled to the Rivian.

As it was explained to me in the Comma discord server:

• Driver+ tells the Rivian what angle it needs the steering-wheel to adjust to, and then applies whatever torque is necessary to achieve that. The more tread on your tire, the less torque on the steering wheel is needed. A bald tire could need 30% more torque to round a corner than a new tire, and the steering wheel knows that and will provide the 30% extra power.
• The Comma 3x tells every Rivian to use the same amount of torque, and does not calibrate for tire wear.

What this means is that if your tires have 4mm of tread, there are some corners that Driver+ handles totally fine (because it's forcing whatever torque necessary to hold the turn radius), but the Comma 3X just peters out and asks the driver to take over (because the torque requested seems to be targeting vehicles with 10mm of tread).

This has led to what I believe requires more driver attention than Driver+. I have extremely high confidence in the Comma 3X's lane centering, but low confident in auto-steering around corners.

THANKFULLY, this seems to be a software fluke. It sounds like Rivian is a special case, so I am hopeful that the software can add some sort of torque multiplier that gets calibrated into the system when you set it up. Until then, I can intervene and pull the wheel where it needs to without disengagement, in order to round corners safely.

Hands-free driving on any road
This by itself it enough of a benefit to me to overpower any complaint/concern I have with the system. There's approximately one road within a 100 mile radius of me that supports Driver+; Interstate 5. There are other highways and straight-ish back-roads that I always used to love to use my Lane Centering on when I had a Toyota. I've not had that functionality for 2 year, until now.

The system is hands free, and it achieves that by monitoring the driver. There are some major limitations:

1. The default software does NOT control speed. There are efforts to add this in software, but may require modification to the wiring harness that you install when you get the Comma 3X. Speed is handled by Rivian's ACC, so you rely on setting the speed with the steering wheel buttons, and it'll still distance you from lead cars with radar.
2. Because speed is not controlled by the Comma 3X, that means it cannot stop at stop signs or stop lights.
3. The steering wheel does not currently rotate past 90°. This seems to be a software limitation, and it is only relevant on some sharper 20 MPH turns.
4. The system is ultimately only using a forward-facing camera, so it has no perception to its surroundings.

So ultimately it's most designed for use on higher speed / straighter roads. But, you can absolutely use it in the city on straightaways. You just need to intervene for turning at intersections, and stopping at lights/stop-signs.

Lane Changes
Have been very comfortable. You turn on the turn signal, and when it's clear you do a light tug on the steering wheel (much lighter than what you need to disengage Driver+).

Once a turn is initiated, it will complete it effortlessly. Even around corners.

Dashcam
Saves/uploads to a website online. I think you can download videos from there? I haven't tried. Seems great thouth.

Installation
Hardware
The Comma 3X on a Gen1 R1 requires removal of trim, routing 8 feet of cables, and mounting an adhesive mount to the windshield. It's also a running joke that you haven't truly experienced a Comma/Rivian install without cutting your finger.

The wiring harness that comes with the Comma gets plugged in underneath the passenger footwell. This requires lots of light, the body of a contortionist, and hands the size of a baby's in order to install it quickly. For me, it took about 45 minutes of cursing, and when it finally went in it was truly a religious experience.

Routing the cable was fairly easy. I've never done trim work, but with the right set of $10 trim priers on Amazon, I popped off 4 separate pieces without any damage.

Adhering the mount was the easiest part. The instructions call for a cure time of 48 hours, however someone in the discord posted a graph showing cure times by temperature. Looked like 90° F cured in as little as an hour, so that what I went with.

Software
Immensely easy. When the system boots up, you're essentially asked to install either the default software of custom software. I just selected Default, and went on my merry way.

Custom software
There are a few custom software packages you can install on the Comma 3X. Mostly just different flavors of driving styles. But there's one custom software that's still in early development that is incredibly promising, which enables "Longitudinal" capabilities. "Longitudinal" in this case means speed control, which opens the door to things like:

• Stop Signs / Stop Lights
• Automatic speed adjustments from stop signs
• Preemptive speed reductions around corners

And more. This elevates the system from an advanced "Lane Keep" system, to a rudimentary End-to-End self-driving system. There will always be limitations, and I'm not claiming it'll reach even level 3 self driving, but much more capable than the current default software.

The caveat is that right now, the only support for it requires a €299 part from a 3rd party that you splice into the wiring harness that comes with the Comma. That 3rd party is the main person doing development on the Rivian integration for Comma, so the cost seems to largely be in support of his efforts.

There is currently no announced plan to support Longitudinal on Comma's default hardware, that I am aware of.

Conclusion
I am super happy to have purchased the Comma 3X. The hardware installation is a bit prohibitive for Rivian owners specifically, but it's one and done and then you never have to think about it again. There is a small safety concern about the decreased amount of steering-wheel torque that the Comma 3X signals to the vehicle, however that seems to be a software issue that needs an edge case built in for Rivian. Until then, the limitations are something that need to be felt out and learned, and interventions do not disengage the system, so you can coax the steering wheel as much as you need without disruptions.

Replying to the original post. Really appreciate you taking the time to write it up. I just got mine last week. I love it. I'm a previous Tesla owner for over 10 years and three different Teslas. I used regular Tesla Autopilot and FSD a lot. I often drive 700 mile trips and Rivian only allowed highway assist on 50% of it. Was very disappointed. I prefer Openpilot to Tesla basic autopilot.
Tesla FSD was a really cool party trick in the city but actually really annoying on the highway in how it would never follow my adjusted speed commands. Was almost like the AI was taking my set speed as a suggestion. So I would always have to disengage it when there was a drastic speed zone adjustment to be made. Also Tesla without forward facing radar wouldn't even let me use adaptive cruise control if the visibility was reduced at all. I like that Rivan has a radar. I don't need to complain about Rivian's adaptive cruise. Prefer it to Tesla's wishy washy camera only distance measuring. It would never keep an accurate distance with the car I'm following.

I also had a really hard time installing the Rivan harness. After spending an hour on the ground contorting and getting sore I watched a few install videos again more closely. I then noticed that the installer used his fingers to get around the large bracket that is in the way. I felt that my hands were too big but I somehow managed to get my fingers around the bracket and push it in. I also found that putting a bench level with the floor of the Rivian really helped with keeping my body straight during the install.

 

[MrMusAddict]

Replying to the original post. Really appreciate you taking the time to write it up. I just got mine last week. I love it. I'm a previous Tesla owner for over 10 years and three different Teslas. I used regular Tesla Autopilot and FSD a lot. I often drive 700 mile trips and Rivian only allowed highway assist on 50% of it. Was very disappointed. I prefer Openpilot to Tesla basic autopilot.
Tesla FSD was a really cool party trick in the city but actually really annoying on the highway in how it would never follow my adjusted speed commands. Was almost like the AI was taking my set speed as a suggestion. So I would always have to disengage it when there was a drastic speed zone adjustment to be made. Also Tesla without forward facing radar wouldn't even let me use adaptive cruise control if the visibility was reduced at all. I like that Rivan has a radar. I don't need to complain about Rivian's adaptive cruise. Prefer it to Tesla's wishy washy camera only distance measuring. It would never keep an accurate distance with the car I'm following.

I also had a really hard time installing the Rivan harness. After spending an hour on the ground contorting and getting sore I watched a few install videos again more closely. I then noticed that the installer used his fingers to get around the large bracket that is in the way. I felt that my hands were too big but I somehow managed to get my fingers around the bracket and push it in. I also found that putting a bench level with the floor of the Rivian really helped with keeping my body straight during the install.

Not sure which software version you're using, but I'll say that I installed SunnyPilot on my 3X yesterday and am more impressed with it than the default software. Couple advantage over stock OP:

1. It has something called MADS, which means it has a mode that let's you manually one-pedal-drive while it keeps steering for you. This has been amazing on roads with advisory speed limits.

2. It can override speed settings, which opens the door to Speed Sign recognition/adherence (up to +15%)

3. It overrides Rivian's stock radar follow behavior (but still uses radar). The super impressive thing to me though is what happens when a car is passing you and you change lanes to be behind them. Rivian Radar would slam on the brakes because your absolute distance is "too close", but SunnyPilot is smart enough to know they're faster than you and will even *accelerate* up to your set speed and maintain a safe distance. Much more predictable to the drivers around me.

 

[gerrylum]

Just FYI, Openpilot Longitudinal also uses the Rivian's radar in addition to vision.

 

[MrMusAddict]

Just FYI, Openpilot Longitudinal also uses the Rivian's radar in addition to vision.

Thanks. Edited my last comment.

 

[JM.]

There’s no f-ing way I’m trusting Comma. I’m happy if it remains an “enthusiast’s” thing and never full consumer product.

Too late, it's a consumer product and sales are ramping up!

 

[Swezey]

Hmm I got a trip to WA from ATX this August. I may need to install this bad boy in my Riv. Preciate the review!

 

[silkyjohnson]

Holy #%!?#%#%%> is this plug hard to get in. The 3 “bump” side goes in towards the seat?

 

[godfodder0901]

Holy #%!?#%#%%> is this plug hard to get in. The 3 “bump” side goes in towards the seat?

Yep. I found the using my left hand behind the bracket and plug and my right hand to guide from the front made it a touch easier. Still a PITA, but manageable, albeit with some hand cramps...

 

[silkyjohnson]

Yep. I found the using my left hand behind the bracket and plug and my right hand to guide from the front made it a touch easier. Still a PITA, but manageable, albeit with some hand cramps...

That sucked

 

[godfodder0901]

That sucked

Yep. My hand hurt for almost two days....

 

[silkyjohnson]

Yep. My hand hurt for almost two days....

My 15 year old finally got it done

 

[vaporindustries]

I have a 2023 RT1 and it took me some time of struggling before I decided to remove the 13 mm bolt to move the plastic housing to the side to give me a little extra room as per recommended by a YouTube video. Even then I was close to giving up and returning the device. Thankfully I was able to get the harness plugged in.

A 1.5 hour drive to Carmel Valley, using Sunnypilot with MADS was great. It felt better than the stock Rivian Driver+. MADS was useful during stop and go traffic.

 

[Jerm]

Prospective Comma customer w/ a 2022 R1T here, I'm an early adopter and don't mind the tweaking to come yet, but I don't want to buy until I know speed control (longitudinal?) isn't going to be an issue w/ compromises like no steering wheel button function or something, whatever that meant. I've been trying to put together what comes with the kit and what it is capable of. If I'm ordering today, do I need to buy anything other than the "Rivian A" harness? What is this longitudinal upgrade kit I see from xnor.shop? Is that necessary? If so, will it be offered from Comma directly?
I wish there was a table of combinations of sw/hw combinations against functionality somewhere so I could make better sense of what I need to buy and what I need to install to get functionality that meets my desired starting point on this endeavor.
Thanks much for any help.

-Jeremy

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