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

[MrMusAddict]

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.

Sponsored

 

[risingphoenix]

Correction: Auto steering is not a problem if you have competent tires. Your tires are inadequate and this is not because they are 4mm, it's because the compound is way too laterally grippy (looking at you OEM Pirelli). If you have better tires, then the comma is leaps and bounds better than Driver+ around tight corners.

Also, this is unlikely to be fixed with software updates as you can't use a multiplier as it will put some drivers (like me) with adequate tires to be over the safety limit for torque generation.

Also, with the add-on harness, the system is now superior to even Gen 2 ADAS. It is far less stressful (for me) even compared with FSD on my Tesla. This option breathes new life into Gen 1 Rivians and for less than $1500 should be on every Gen 1 owner's short list.

 

[schlosrat]

Great write-up! I'm very excited to see the progress on this!

 

[MrMusAddict]

Correction: Auto steering is not a problem if you have competent tires. Your tires are inadequate and this is not because they are 4mm, it's because the compound is way too laterally grippy (looking at you OEM Pirelli). If you have better tires, then the comma is leaps and bounds better than Driver+ around tight corners.

Also, this is unlikely to be fixed with software updates as you can't use a multiplier as it will put some drivers (like me) with adequate tires to be over the safety limit for torque generation.

Also, with the add-on harness, the system is now superior to even Gen 2 ADAS. It is far less stressful (for me) even compared with FSD on my Tesla. This option breathes new life into Gen 1 Rivians and for less than $1500 should be on every Gen 1 owner's short list.

Correction to your correction; While auto-steering on Comma 3X is improved with more competent tires, the limitation is ultimately due to an overgeneralization of torque settings on OpenPilot. Driver+ torques adequately around every I5 corner I've come across, but OpenPilot veers onto the shoulder for me because not enough torque is being signaled by the 3X.

I have my fingers crossed that it can be solved in software. I know it's rich for non-developers to say "it should be easy", so I won't say that. But I will say it should be possible for them to add in some kind of modifier that gets calibrated to be stronger/weaker per vehicle.

Agreed that OP Longitudinal is superior to Gen 2 ADAS. I'll be playing around more without it to see if I truly need it.

 

[risingphoenix]

Correction to your correction; While auto-steering on Comma 3X is improved with more competent tires, the limitation is ultimately due to an overgeneralization of torque settings on OpenPilot. Driver+ torques adequately around every I5 corner I've come across, but OpenPilot veers onto the shoulder for me because not enough torque is being signaled by the 3X.

I have my fingers crossed that it can be solved in software. I know it's rich for non-developers to say "it should be easy", so I won't say that. But I will say it should be possible for them to add in some kind of modifier that gets calibrated to be stronger/weaker per vehicle.

Agreed that OP Longitudinal is superior to Gen 2 ADAS. I'll be playing around more without it to see if I truly need it.

Let us know how you feel after you get competent tires.

 

[Donald Stanfield]

Correction: Auto steering is not a problem if you have competent tires. Your tires are inadequate and this is not because they are 4mm, it's because the compound is way too laterally grippy (looking at you OEM Pirelli). If you have better tires, then the comma is leaps and bounds better than Driver+ around tight corners.

Also, this is unlikely to be fixed with software updates as you can't use a multiplier as it will put some drivers (like me) with adequate tires to be over the safety limit for torque generation.

Also, with the add-on harness, the system is now superior to even Gen 2 ADAS. It is far less stressful (for me) even compared with FSD on my Tesla. This option breathes new life into Gen 1 Rivians and for less than $1500 should be on every Gen 1 owner's short list.

It cannot change lanes by itself, but Gen 2 can. Therefore, it is not superior to Gen 2

 

[godfodder0901]

It cannot change lanes by itself, but Gen 2 can. Therefore, it is not superior to Gen 2

Gen 2 doesn't change lanes by itself, it does so when commanded. Open Pilot will as well, you just command it in a slightly different way.

 

[Donald Stanfield]

Gen 2 doesn't change lanes by itself, it does so when commanded. Open Pilot will as well, you just command it in a slightly different way.

Making the lane change by physically steering and clicking the blinker stalk are very different levels of actuation. One is 100% manual and one is 5% manual. If you're not paying attention comma WILL NOT stop your truck from hitting something in the next lane. Gen 2 will. Not at all comparable.

 

[risingphoenix]

Making the lane change by physically steering and clicking the blinker stalk are very different levels of actuation. One is 100% manual and one is 5% manual. If you're not paying attention comma WILL NOT stop your truck from hitting something in the next lane. Gen 2 will. Not at all comparable.

With the add on harness comma utilizes the BMS and will not change lanes and wait until BMS is clear before it does change lanes. Again, comma is 100% superior to gen 1 and gen 2 ADAS in Rivian. If you haven't utilized the comma or have experience with it perhaps keeping your thoughts to yourself will save you the embarrassment of confidently making blatantly incorrect claims.

 

[Donald Stanfield]

With the add on harness comma utilizes the BMS and will not change lanes and wait until BMS is clear before it does change lanes. Again, comma is 100% superior to gen 1 and gen 2 ADAS in Rivian. If you haven't utilized the comma or have experience with it perhaps keeping your thoughts to yourself will save you the embarrassment of confidently making blatantly incorrect claims.

Do have to manually change the lane or no? Thought so.

 

[captainjp]

Yeah, just seems like a hack to add a poor man’s Gen 2 capabilities to Gen 1. If one is happy with that, cool. I’m not convinced, however

 

[risingphoenix]

Do have to manually change the lane or no? Thought so.

Yes, with comma you have to put the turn signal on. That is all. Comma checks to see if BSM is clear and will engage if clear after a user preference chosen time interval. Meanwhile, I can use comma on any road I wish (even off road) and can engage at 20mph. And I can choose to use the comma for steering while I control the accelerator pedal for better speed control on local roads less than 25mph (that's called MADS). And it does not disengage when I nudge the steering wheel (ie to give a biker more leeway). And it doesn't ping pong all over the road like Driver+. And I can use it while towing. And I can set how aggressively I want the driving personality to be in addition to many options regarding driving models. And I can set it to read speed limit signs and automatically set my cruise control to that speed or a user selected % above that speed. And it's continually getting better almost daily. I'm sure I've missed other MAJOR advantages over the Rivian implementation of ADAS. Ask anyone WHO ACTUALLY OWNS A COMMA DEVICE and they will tell you for Gen 1 vehicles it is like having a new car.

We'll wait for your point by point comparison between any Rivian ADAS implementation and the above. If you think the above options are "a hack", then you do you. Good luck with the slow as hell (or non-existent) Rivian ADAS development cycle. Over at OpenPilot changes are happening daily.

 

[MrMusAddict]

Let us know how you feel after you get competent tires.

Yeah I'll be replacing my tires in the next 5k miles I think. Fully expect things to improve then.

BUT, it's still a software flaw that will cause degraded performance over time with tire wear. It'll benefit everyone if the devs add in a calibratable torque multiplier so that steering performance is consistent for everyone. The steering wheel column definitely has the power to support it, but OpenPilot is variably too timid.

 

[Donald Stanfield]

Yes, with comma you have to put the turn signal on. That is all. Comma checks to see if BSM is clear and will engage if clear after a user preference chosen time interval. Meanwhile, I can use comma on any road I wish (even off road) and can engage at 20mph. And I can choose to use the comma for steering while I control the accelerator pedal for better speed control on local roads less than 25mph (that's called MADS). And it does not disengage when I nudge the steering wheel (ie to give a biker more leeway). And it doesn't ping pong all over the road like Driver+. And I can use it while towing. And I can set how aggressively I want the driving personality to be in addition to many options regarding driving models. And I can set it to read speed limit signs and automatically set my cruise control to that speed or a user selected % above that speed. And it's continually getting better almost daily. I'm sure I've missed other MAJOR advantages over the Rivian implementation of ADAS. Ask anyone WHO ACTUALLY OWNS A COMMA DEVICE and they will tell you for Gen 1 vehicles it is like having a new car.

We'll wait for your point by point comparison between any Rivian ADAS implementation and the above. If you think the above options are "a hack", then you do you. Good luck with the slow as hell (or non-existent) Rivian ADAS development cycle. Over at OpenPilot changes are happening daily.

You can engage D+ at any speed you want as well. You cannot use it on unmapped roads yet, but that will be available this year. You can also control the accelerator pedal with D+. D+ doesn't ping pong on Gen 2. You cannot set the level of aggressiveness you want the driver profile to have, as it automatically adapts to traffic conditions. The logic there is decent, and hopefully will improve. You can set your Rivian to adapt to speed limit signs with the cruise control as well, and do a % above.

So far, the only features you have are the ability to use them on unmapped roads, which is a planned upgrade, and nudging the steering wheel, not disengaging the system, which I consider a negative, not a positive. If I need to correct anything, I want the system off until I deem it safe to turn it back on. I don't consider using it while towing to be a plus either, as I see that as an unsafe practice.

I've seen more than one person who has a comma comment that the system will NOT do lane changes automatically so unless this feature has been added in the last few weeks you're full of it.

 

[risingphoenix]

Yeah I'll be replacing my tires in the next 5k miles I think. Fully expect things to improve then.

BUT, it's still a software flaw that will cause degraded performance over time with tire wear. It'll benefit everyone if the devs add in a calibratable torque multiplier so that steering performance is consistent for everyone. The steering wheel column definitely has the power to support it, but OpenPilot is variably too timid.

It's a safety limitation, not based upon being timid. Maybe they'll implement something, maybe they won't. But the main branch team will not allow something that threatens the safety of the system. It's open source, so you should feel free to develop your own fork and configure a system that works better for you. I have pretty high torque tires so would be happy to try your fork if you need help with testing. That's the beauty of open source compared with the approach Rivian and other automakers are taking and the rapid development is why Open Pilot is second only to FSD in safety and features (I would actually argue it's better than FSD given the lack of phantom braking and much more collaborative steering but that's just my opinion).

Sponsored