Bluetooth Mesh And DALI

It is not often that a perfect match is found. But this is the case between Bluetooth mesh and DALI. One is wireless, the other is wired. One distributes the control functions, the other has it centralized. Both are used for professional lighting to control lights and capture data: usage statistics, energy, sensors.

I have been working with Bluetooth mesh and DALI for many years. Initially we had the idea to keep the DALI system architecture and use Bluetooth mesh as a wireless carrier for DALI. But over the years, as Bluetooth mesh has been pushing the intelligence and control functions to the end nodes, another approach started making much more sense

Let DALI pick up from where Bluetooth stops:at the edge of a luminaire. Luminaires today are fairly complex. Long gone are days of a hot tungsten wire - replaced now by a network of electronic drivers with built in intelligence and sensors. An LED driver is a networked node. There may be just a single one inside a luminaire or there may be several. Also what has become a norm today are sensors. And it is not just that a luminaire has an occupancy sensor. It may have more than one, if it has multiple "light channels", like a free-standing luminaire that serves two adjacent desks. Then they have ambient light sensors (to adjust the output depending on the level of natural light) and several environmental sensors: CO2, pollen, temperature, humidity, noise. Yes a modern luminaire is a sensor hub. And DALI is the network inside a luminaire that connects all those network nodes: the drivers and the sensors.

DALI-2 also has one brilliant attribute: it delivers power over the same pair of wires it uses to communicate. And because it is a bus system, it requires no hubs, no switches. And no additional power supplies for connected nodes. Think of it as PoE, just simplified (which means it is very well cost-optimized).

All these architectural concepts perfectly fall in place together: use DALI-2 network to wire the components inside a luminaire, then connect that bus to a Bluetooth mesh node. This node acts like a gateway for the DALI bus. And this Bluetooth node, as it has it own edge-distributed intelligence, serves as the application controller for the luminaire. Then the luminaires mesh wirelessly together forming a collectively intelligent system. A system with perfectly balanced message traffic and no single point of failure, working synchronously like a flock of birds.

Now the beauty is, this all is going to be fully standardized, from top to bottom, thanks to the joint effort of Bluetooth SIG working together with DiiA (the organization managing the DALI standards). I am especially excited to work on standardizing the D4i (which stands for DALI for IoT and focuses on intelligent luminaires) specifications to interoperate with Bluetooth mesh.

Intelligent lighting has just become simple. This will have a widespread impact on the entire market category. If it is simple (it is), less expensive (it is), more capable (it is) and "just works" (it does), there is no reason why would anyone use any other architecture.

To dive deeper into how DALI works together with Bluetooth, I suggest the great post by Chuck Sabin at https://www.bluetooth.com/blog/bluetooth-dali-accelerating-the-future-of-iot-enabled-commercial-lighting/. Then join me later in August for a session at the (Virtual) IES Annual Conference, where I will be covering in details the data-related business opportunities enabled by D4i and Bluetooth mesh.

PS. This week (on Thursday) there is the Bluetooth Mesh Masterclass webinar at Lux and you are all welcome to join!