We Tested OpenPilot, the $1,199 Device That Adds Entry-Level Autonomy to Your Car

Comma AI's OpenPilot enables Level 2 driver assistance in more than 100 cars on the road, and it's already available to buy today.

When my wife and I were shopping for a new minivan last year, one of the requirements was to find something a bit more comfortable for long-distance driving. I don’t mean soft seats and 50 cupholders—as someone who appreciates a well-executed driver-assist system, I was set on finding a vehicle that had not only lane-keeping but lane-centering for that extra… extra. In case you didn’t know, though, vans aren’t exactly the epicenter of cutting edge technology, unless a built-in vacuum satisfies your definition of tech. 

Alas, I came up empty. And like tens of thousands of dads every year I ended up with a Honda Odyssey in my driveway. But unlike most of those chumps, I can get a little extra help from technology when it comes to actually driving the thing. On the highway, at least.

That’s because, in 2020, there’s actually an aftermarket solution for upgrading your car’s ADAS suite to offer true SAE Level 2 driving assistance capabilities—think Tesla’s Autopilot, or Cadillac SuperCruise. Meet OpenPilot, an open-source autonomous driving project from a small, California-based startup called Comma AI.

With the stated goal of “solving self-driving cars,” Comma sells a smartphone-sized device that interfaces with your car’s existing sensors, augmenting whatever features—think lane keep assist, or radar cruise control—are offered by the factory setup. And the difference is truly astounding. You may think your car’s lane-keeping system is pretty good, but unless you have one of the two factory Level 2 systems mentioned above, you haven’t experienced the kind of polished, holistic solution that’s on tap here.

More than 100 vehicles on the road today are supported as hosts for Comma’s system, including my new Odyssey. It can’t be overstated what a tipping point this is. Four years ago, the idea that you could buy a simple, plug-and-play aftermarket driver-assist setup that would work as well as or better than a factory system was laughable. Today, as more cars emerge from the factory wired up with endless sensors, monitoring systems and even cameras, ADAS looks more and more like an untapped area for the ever-present aftermarket to capitalize. 

But does it all work like it’s supposed to? After a year of hands-on experience with my OpenPilot-equipped Odyssey, it’s time to talk about the good, the bad, and if it’s worth upgrading your ride.

The Promise

Before we dig in, here’s a refresher on the SAE levels of vehicle autonomy so you understand just where OpenPilot falls on the self-driving spectrum. It helps to set your expectations as a driver, and understand where not to get too comfortable.

via SAE

So, everything Comma makes today is SAE Level 2 capable, meaning the driver can expect OpenPilot to support their driving, but not take over in a sense where they can divert their attention from the road. Just like Tesla’s Autopilot…officially speaking. OpenPilot will provide the steering, acceleration, and braking instructions to the vehicle and supplement any radar-based cruise control or lane-keeping already installed from the factory.

OpenPilot also makes driver monitoring mandatory, meaning that it will know whether or not you’re paying attention to the road. Its cabin-facing camera uses facial recognition to detect a driver’s eyes and will intervene should a driver begin to drift off to sleep or look at their phone.

What OpenPilot does not do: Make your vehicle a “self-driving car.” There is a difference between a car being able to control itself in limited situations while you’re still paying attention, and a car that can safely whisk you anywhere in the country while you nap in the backseat. This is the former, not the latter.

And just as a quick refresher, because it’s always good to do so: you do not own a self-driving car. This won’t change that.

The Device

via Comma

A cool $999 is your cost to enter the world of what comma calls “chill” driving. That price buys you a Comma Two, which is a cleverly disguised Android smartphone fitted with some sensors, thermal management, and a custom 3D-printed case to package the whole deal into a small, convenient appliance. A separate $200 wiring harness is required to interface the device with your car.

The Comma Two is an evolution of the company’s earlier Eon dev kit which I purchased with my own money for around the same price, and you’ll see me using it later on. While the base phone remains the same LeEco Le Pro 3, its supporting hardware has been updated. Comma founder George Hotz told me that remaining on a consistent hardware platform was key to Comma’s accountability—there’s no worry about early adopters having to book service appointments to retrofit hardware like some other automakers currently on the market.

Speaking of which—why a smartphone? Tesla has an army of supercomputers running around on the road, so it’s hard to believe that a simple Android phone can be the brains steering your car along a highway. According to Hotz, it just makes sense. 

“There’s no part of that cell phone we don’t use,” Hotz said, adding that the company plans to sell the Comma Two for the foreseeable future, so those looking to make the jump can do so confidently and not worry about running on obsolete hardware in a year or two. Also, remember the old line about how your iPhone has 100,000 times more processing power than the Apollo 11 computer? 

The screen is used to show the driver how the device is interpreting its forward view. That includes the speed limit set by the driver, the lanes identified by the software, and any vehicles in your path of travel. Driver monitoring and braking status can also be displayed. Meanwhile, the phone’s cabin-facing camera is used to monitor the driver’s attention and ensures that someone is always keeping their eyes where they belong: on the road.

When you reach your destination, the Comma Two will automatically upload the recorded footage of the drive to Comma’s datacenter for storage and retrieval (no external SD card required). This also ensures that Comma can use the footage to train its own test models and improve the driving experience in the future. Comma also offers an optional subscription service to utilize the phone’s built-in cellular radio to perform all of this (and over the air updates) without the need for a home wireless network.

The Installation

Compared to the early days of OpenPilot, installing the Comma Two is a breeze.

First comes the vehicle harness, which allows the Comma Two to perform the CAN-layer proxying needed to send gas, braking, and steering controls to the vehicle’s various computers.  After gaining access to your vehicle’s camera, simply slide the Comma vehicle harness between the camera and the factory connector and reassemble the trim.

Next, mount the Comma Two to the windshield using the adhesive mount included with the device, and the physical labor option of the job is finished.

The Driving Experience

Out of the box, the Comma Two does nothing but act as a dashcam. The secret sauce is found by installing OpenPilot on the device using the instructions found in Comma’s wiki. Once installed, the software will walk you through some basic training (and test you on it, so pay attention) before allowing you to use it on the road. You’ll then need to perform some basic calibration by driving around with OpenPilot disengaged for several miles, and the setup will finally complete. This process only needs to be completed once after installing OpenPilot on the device.

Now that we’ve got that out of the way, we can talk about the fun part: driving.

Comma’s goal is to “make driving chill”—and it does this by enhancing a car’s radar cruise and lane-watch systems to make minor corrections that would normally need to be applied by the driver. Just like those independent systems, OpenPilot will keep you in your lane, stop you from running into other cars, and generally handle low-stakes highway driving. The difference is how well it does those things. For example, watch how OpenPilot handles a not-so-small curve in the highway below:

The Drive

If you’ve seen the marketing hype behind ADAS suites like Ford’s Co-Pilot360 or Nissan’s ProPilot Assist or even Honda Sensing, you might not think that’s a big accomplishment. Lots of cars can pull this trick today, right? No so fast. First, the independent promises of each ADAS component in most cars tend to fall apart when they’re forced to work together to approximate limited self-driving functionality.

For the Odyssey, Honda Sensing‘s constant ping-ponging across the lane and failure to steer through even the most basic highway curves was enough to seek out OpenPilot. But the other benefit is that it can work with slightly older vehicles that use early, less accurate iterations of that technology.

Of course, just like other solutions on the road, you’re required to pay attention to what’s around you. You are still driving the car, not the cell phone mounted to your dashboard. But it does offer a sense of calmness (“chill”, if you will) for long road trips and smooths out the rough edges you get from traffic and getting cut off.

In the past year, OpenPilot has even added the ability to assist in lane changing. Simply verify the desired lane is clear of other vehicles, engage the turn signal, and nudge the steering wheel—OpenPilot takes care of the rest.

Nudging the steering wheel after engaging the turn signal will initiate a lane change., The Drive

Another great thing about OpenPilot is that it’s designed to make factory vehicle controls still feel factory. Hotz explained that OpenPilot is designed on an abstraction layer, with the user-interfaced controls hidden behind the OEM vehicle programming that you’re already used to using. Activating OpenPilot was as simple as engaging the cruise control in the Odyssey, and turning off its lane-keeping was still achievable using the OEM buttons on the steering wheel meant to disengage the Honda Sensing suite.

Now, there are some limitations. Most of these are implemented by the host vehicle and are meant to protect the driver and those on the road around them. For example, the Odyssey (like many Honda vehicles) has a limit on the amount of torque that the computer will apply to the steering wheel. That means while OpenPilot is fine for most highway conditions, it can be a letdown on especially curvy stretches.

Some community members have come up with custom firmware for several Honda Electronic Power Steering (EPS) systems; however, flashing an expensive part with software that controls where you can steer (and potentially void your factory warranty) isn’t something everyone wants to do.

The same goes for longitudinal control. Some vehicles support stop-and-go traffic with OpenPilot engaged, while others can make use of the unofficial and unsupported “Comma Pedal” to add the functionality in their vehicles.


Even if you’ve driven a modern vehicle with lane centering, I promise you’re in for a treat. The first time behind the wheel of a vehicle with its ADAS suite upgraded by OpenPilot is like upgrading your iPhone 3GS to a brand new iPhone 11 Pro Max. It’s bigger, it’s better, and it’s all-around more robust.


Community and Support

One of my favorite things about OpenPilot is the community behind it. Because the software itself is open source, the community can keep track of what changes are being made, and even propose modifications of their own. And if you wanted to, you could even branch off your own custom fork of OpenPilot. Hotz says that Comma is completely okay with this as well.

“The only thing that we really care about on the forks is making sure that you’re not doing anything blatantly unsafe. You can’t disable driver monitoring and you should use our safety code. Other than that, have at it—that’s why it’s open source.”

Some developers have even built and actively maintain support for vehicles not officially supported by Comma’s solution—there’s even one for early examples of the Tesla Model S. Some developers release unofficial versions want extended functionality or tweaks to the driving behavior, while others completely branch out from the core software and re-brand. 

If you’re having difficulties with the product, you can jump onto Comma’s official Discord server and chat directly with more than 2,000 active users of OpenPilot to help solve a problem, or even some of Comma’s own staff. It’s not uncommon to find the founder lingering in the channels, too.

Comma’s biggest growing pain seems to be the rapid rate at which it has matured. Keeping up-to-date documentation on every single problem from vehicle to vehicle has rightfully become a challenge. And while resources like the Wiki exists, many people will instead have to find answers to their questions via Discord search or pinned topics. This can be daunting for non-tech savvy individuals, but part of the learning curve for any early adopter.

But it also brought the collective together towards solving common problems, especially in the maker community. For example, when my out-of-warranty Eon’s fan circuit board failed, I designed and 3D printed an enclosure for another cooling solution and shared it with the community. Other individuals have even designed complete enclosures to mount the necessary hardware to mount different OpenPilot-compatible devices (like a stock LeEco Le Pro 3, or OnePlus 3T) on their windshields.

What’s Next?

This is a tough one. Comma’s goal of “solving” self-driving cars is quite open-ended, and Comma’s work is slated to provide a means to an end—whatever that means might be. For now, that’s its Comma Two running OpenPilot.

Hotz says that Comma plans to continue to refine OpenPilot to make the use out of the hardware it already shipped. Comma’s next direct update, for example, reduces the device’s CPU workload by one-third, and the compute savings will enable it to build in more complex 3D models (which it will be doing in the next major release) and even work towards detecting stop signs and red lights in the near future.

“We’re here to push the boundaries of what’s possible. We’re here to build things that are actually magic,” said Hotz, “You can take a tiny thing out of a box, stick it on your windshield and watch it drive your car—no one thinks this is possible.”

Right now, Comma says its users have driven around 25 million miles—compare that to Waymo’s 20 million and numbers start to look a bit serious. It’s a far shot from Tesla’s 3 billion or more, but given the number of Comma Devices versus Tesla-branded cars on the road, it certainly is a running start.

I’ll admit, I felt that magic that Hotz is talking about during my first drive with OpenPilot. And again during my first long commute. And every day that I sit in the Odyssey and engage cruise control. Comma is the only company making an open source solution for self-driving, and its hardware isn’t out of the ballpark for being attainable. Think of it as an introduction to automation for the price of coilovers. If you’re someone who takes long drives frequently or just wants to freshen up the performance of their vehicle’s factory lane keeping, Comma’s got you covered. You too, can feel the magic.

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