At the only and likely last LED and solid-state lighting (SSL) sector event held live and in person in 2020, Cree Lighting took LEDs Magazine Sapphire honors in both the Lighting for Health and Wellbeing product category and in winning the Illumineer of the Year award. We broke away from our black-tie Sapphire Gala format in 2020, and instead presented the awards on the flight deck of the historic Midway aircraft carrier now docked as a museum on the San Diego Bay. Bob Rogers and Kory Liszt accepted the Illumineer honors, and we have since had the opportunity to interview the software specialists about the innovation and inspiration that went into Cadiant.
LEDs Magazine: Hi, Kory and Bob. Congratulations on winning our Sapphire Illumineer of the Year award for 2020. We had some outstanding nominees covering many angles of the LED and SSL sectors. Approaching Strategies in Light and our Sapphire Gala with an outstanding LED development team and horticultural lighting experts also nominated, what were your thoughts?
Kory Liszt: It was truly an honor to be nominated among such a talented group of engineers. It is exciting to see how the industry is being shaped and propelled into the future through the innovation of many different individuals.
Bob Rogers: It was an honor to accept the award for our teams given the deep talent that the field of nominees represented. Although much of the look and feel of the Cadiant Dynamic Lighting Experience is accomplished in hardware thanks to our excellent hardware designers, control of that look and feel is enabled entirely in software, and so we were pleased that the integration of a hardware/software solution was recognized as being compelling in its effect on those who experience Cadiant.
LEDs: We have called on the industry regularly in the past year to move toward a quality-of-light mission. The so-called LEDification movement was great. The industry figured out how to replace legacy sources and even improve on some existing technologies. But efficacy has really driven the movement. What are your thoughts on where the LED lighting industry in general is heading and/or where should it head?
Liszt: As LEDs quickly become a prominent commodity, differentiation in the market is going to be key. The next steps are to move beyond simply providing light, and more towards defining unique ways to provide value beyond light. We, as an industry, need to test the boundaries of the lighting tradition and ask our end users what new problems we can solve. Lighting is unique such that it is in every space and evenly distributed among that space. By adding intelligence, sensing, notification and IoT [Internet of Things], we can begin to push the bounds of what is possible.
Rogers: I feel that controls are headed for the cloud, as is storage and analysis of data gathered from the lighting sensors. I also believe that more could be done to provide home users with simple-to-commission and cheap-to-acquire home lighting automation systems that would integrate well with other platforms such as security systems and voice-activated systems like Alexa.
LEDs: Cadiant certainly has a quality-of-light story inherent in the realization of the technology. Obviously, there is far more in the dynamic design and we will get to those other features in a moment. But how did you approach the issue of light quality as the Cadiant concept evolved?
Liszt: Quality of light was a critical component of the Cadiant design. Our team of LED engineers spent many hours formulating the appropriate ratio of sun to sky to ensure the mixing was visually acceptable, while still maintaining high CRI. In addition, the custom drivers created for the project by our team of electrical engineers provided very strict control over each of the nine strings. The very low current control and smooth dimming capabilities are the foundation of the quality light experienced with every Cadiant.
Rogers: The mechanics of keeping the dynamic lighting so smooth that it would be imperceptible was a driving concern. Even when in demo mode, where a user can view a time-compressed day of dynamic lighting in a few minutes, we designed this with smoothness in mind. Maintaining the proper ratio of sun to sky across dim levels was also built into the hardware intentionally to keep the software relatively simple in this regard.
LEDs: In describing the Cadiant experience, it’s tough to capture the complexity of the tunability and lighting for health and wellbeing angles in a short summary. Perhaps each of you give me your best description of the concept in twenty words or less.
Liszt: The Cadiant system creates a unique experience using the Dynamic Lighting feature. This allows the user to transform the space and give the occupants the feeling of the outdoors. Humans have been designed to operate at a certain rhythm throughout the day and Cadiant helps support that rhythm even when we are indoors.
Rogers: With Cadiant, the glow of my office walls changes throughout the day though I have no windows.
LEDs: In the Sapphire entry essay, there was mention of the sun and sky panels in the products. It’s easy to see that there is the panel parallel to the floor along with the perpendicular panels forming four sides. Can you discuss the experience that the design is intended to evoke? In an actual recessed skylight those side panels would reflect diffused sunlight, right? How did the Cadiant team see the system functioning?
Liszt: The Cadiant was designed to dynamically change the lighting in the space to give the occupants the feeling of a skylight. The sun and sky panels work together to adjust the angle of the projected light, mimicking the sun’s illuminance on the surfaces below.
Rogers: We went back and forth on this a few times. In the end, we wanted the user to sense that the sun was in the east in the morning by brightening the west wall. This is accomplished by making the east sun panels brighter than the west sun panels. This works in most cases where the user is simply in the room working and not staring at the Cadiant luminaire itself. When looking directly at the fixture, it may feel backward as one might expect the west wall of the light plenum to be brighter, but we felt that the feel of the room as a whole was more critical than the impression while looking directly at the fixture. Few people (except us) spend much time staring at overhead lights while everyone benefits from the feel of those lights.
LEDs: There are no mechanics of any kind in the product, right? Are the effects strictly achieved by precisely controlling the large numbers of LEDs in the system?
Liszt: The Cadiant has over 1800 LEDs with nine independently-controlled strings and well-designed optics to create the sun and sky effects. There are no moving mechanical parts.
Rogers: Yes, there are no moving parts. The light and the colors presented are created using various combinations of differently-colored LEDs.
LEDs: Now let’s talk about software. When we conceived the Sapphire program, we didn’t think about software engineers taking the Illumineer award. That was shortsighted as the industry was well into the smart SSL transition even seven years back. And you aren’t the first software-oriented winner in our Sapphire history. But I’d like to ask each of you how you came to the world of lighting. What attracted you to ply your trade at Cree Lighting?
Liszt: I came to Cree Lighting as a wireless design engineer. My passion was in designing wireless communications, and as I looked into the lighting industry, I saw tremendous opportunity as the world was transitioning to connected things. The lighting industry is inherently set up for smart technologies that could positively impact people’s daily lives. The opportunity of what is possible drew me into the lighting world.
Rogers: My background is widely varied. I’ve worked in anti-submarine warfare, commercial avionics flight safety, satellite telecommunications, cellular communications, server infrastructure firmware, and self-checkout systems. Cree Lighting had always been on my radar. I got in the door due to my communications test background. I have not had as much fun in a job in many years before coming to Cree Lighting. The stuff we work on is fun from an engineering viewpoint, and the people who make it happen are bright, friendly, and positive.
LEDs: The fact that Cree Lighting nominated you two is indication that the software development was perhaps the most critical element of the product development. Can you quantify in any way the magnitude of the software project? And it’s way more than writing code, correct? You have to understand the challenge at hand, right? — and that’s some complex human physiology.
Liszt: The Cadiant Dynamic Skylight is more than just a fixture: It is a complex system of LEDs, optics, mechanical design, electrical design, software, firmware, APIs, user interfaces, and much more. The system design relied heavily on software to take an already impressive fixture and provide the features and customizability that creates the Cadiant Dynamic Lighting Experience. The heart of the Cadiant functionality was determined over several years of research and mockups to determine not just how the light would perform but how the light made people feel. While this is hard to quantify, our research and development team did a great job capturing the essence of what it takes to transform the space and bring the outdoors in. The result was a complex system with multiple innovative concepts that the software was able to solve in a flexible and efficient way. To simplify these complexities, a comprehensive system specification was created to break down all the features of the complex system and turn them into manageable tasks. The system was developed in pieces and slowly put together like a puzzle until the full system came together to create the Cadiant.
Rogers: I didn’t personally get into the human physiology aspects of the project too much. This was done by the original creators of the concept. What made Cadiant complex was the integration of several key components to pull it off. There’s the light fixture itself, which has a radio interface talking to multiple light drivers on the device. Then there is a gateway component that is a member of the lighting network and pipes commands from the tablet to the fixtures and data from the fixtures to the tablet. And then there is the tablet which acts as the human interface for the controls of the Cadiant luminaire. When a person presses a button on the tablet and sees the Cadiant change its colors and/or dim levels, more than a handful of microprocessors are involved. The devices speak to each other across different interfaces using different protocols. Integrating all of this into a working system was the challenge. Of course, we had frequent feedback from marketing as we implemented the ultimate design to keep us honest and on the path of something that would be marketable.
LEDs: When we talk generally about tunable lighting, the application range is huge. In many settings such as a restaurant, tunability is about ambience and luring the customer with a feeling of comfort. In schools, tunability is about providing the best learning environment. And ultimately tunable lighting can be about lighting for health and wellbeing or human-centric lighting (HCL) where people under the light have an improved quality of life. Do you see Cadiant addressing the entire range? And do we even need to expand our thoughts about the range for such technology?
Liszt: The Cadiant system can be used to solve all of these applications. The software provides ultimate flexibility with a simple user interface that allows the user to create the desired environment. Scenes allow the user to set the mood at a restaurant or prepare students to take a test. Dynamic Lighting can make any office feel as if natural light is prominent in the space. The software was created such that the user can customize the Cadiant operation to fit their specific needs and possibly solve problems we haven’t even thought of yet. This is the exciting part of this project, to see what new ways our customers use Cadiant to solve a unique problem.
Rogers: I do believe that we cover most of the breadth of the current needs of the market. There may be other areas that could benefit from using light to influence
human reactivity such as prisons, psychiatric wards, theaters, and performance halls. If we wind up having manned outposts on other heavenly bodies, then I can see the need for a richer and more automatically controllable source of light.
LEDs: If we didn’t get to an answer for this simpler question before now, how wide is the market for Cadiant? Give me the application extremes in which you believe it might be installed.
Liszt: Cadiant can be used in most any indoor applications. We have some customers who are combining many of these fixtures side by side to create the appearance of a large “window” in the ceiling.
Rogers: They are very compelling in places where access to the sun is very limited, such as extreme northern areas (think Alaska in wintertime), hospitals where 12-hour shifts are common, interior offices, and schools.
LEDs: I know companies in any industry don’t like to talk about competitors or competitive products. So we won’t directly ask such a question, but we will come close. Signify recently announced a tunable product called NatureConnect. That offer includes a skylight-type luminaire and can be combined with downlights, wall washers, and more working in sync. Will Cree Lighting look to expand Cadiant’s feature set in complementary products?
Liszt: The Cadiant system and the technology used is only the beginning of what is possible in creating value beyond light.
Rogers: Cadiant is but one device in a broader spectrum of devices that can be placed in the same lighting network. It can be installed today with color-tunable troffers and eventually with our Stylus linear portfolio. The tablet can be used to create scenes and profiles on any of these devices just like it can on a Cadiant. The user interface tunes itself to the type of device being controlled so that the user sees only the controls needed to control his fixtures, or if the user mixes fixture types in the same control group, then the UI presents a super-set of the controls.
LEDs: Is it in any way comforting to have a company like Signify essentially second Cree Lighting’s thoughts on a significant application opportunity?
Liszt: It is always good to hear positive feedback from others within the industry. While, yes, we are competitors, we are all trying to move toward the same goal, creating new and innovative products that redefine our industry.
Rogers: We knew that the concept was brilliant as soon as our advanced technology team presented it. Creating time and labor in our engineering budget to realize the design was the challenge as we had other commitments to handle. So, it isn’t surprising to me that another company thought that it was a worthwhile goal.
LEDs: In closing, can you discuss how long Cadiant was central in your work focus and offer some scope as to the magnitude of the challenge?
Liszt: The Cadiant project was a multiyear journey that was created by many engineers and scientists. I personally spent over a year as part of the project team as the principal systems engineer. The biggest challenge for me was getting all the research and development data, multiple technologies, and marketing requirements to work together to create the final product. Taking something so complex and ensuring the pieces all fit together in the end to create a new experience for our customers was one of the most rewarding experiences of my career.
I was personally directly involved with Cadiant for about a year, but I was also involved with some of the foundational technology for a year and a half before that. We had already established new control and data flows between fixtures and a gateway. We augmented these heavily to support the Cadiant functionality. For many on the team, working on a more open system with APIs, security, an admin console, new firmware update capabilities, and software containerization, this represented a massive learning curve both from the code level (with its back end and front end) and from a test perspective given the many failure points within the system to discover and fix. The team worked very hard to overcome these obstacles and to deliver this system.
LEDs: We again congratulate you on the Illumineer of the Year recognition and sincerely hope you appreciate the honor. We’d ask one more thing of you, and that is what were your thoughts when the award was announced at the Gala? How did the entire Cadiant team react, especially after the product won in a category also? And how do you two feel now several months down the road?
Liszt: It took an entire team to develop the Cadiant Dynamic Lighting Experience and we are honored to be recognized. The announcement at the Gala was a very
exciting moment because I believe we have started to pave a new path for future engineers and the lighting industry. Lighting is more than just providing light but rather an experience that impacts people’s lives. Through our innovation, we can provide value beyond light.
Rogers: I am still quite proud of the award and will be for a long time to come. The ability to ship products like this that change a fundamental, like how we look at lights, is why I became an engineer. I have several things that I’ve worked on over the years that I am particularly proud of, and this is the latest addition to this list. The entire team had already gone all in to deliver this by doing what it took to bring it to market. We continue to innovate as we look to the future of our products and are excited by our pipeline.
Be on the lookout for announcements about the 2021 LEDs Magazine Sapphire Awards program.
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