1. Introduction
Bluetooth® LE-mesh connects multiple Bluetooth® Low Energy technology (BLE) devices with mesh networking capability for internet of things (IoT) solutions.
| Bluetooth® Low Energy mesh illustration |
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Mesh network has a many-to-many topology, with each device able to communicate with every other device in the network.
The Bluetooth® LE-mesh communication is done using messages relayed by the devices which are part of the mesh network (called nodes). In this way, the end-to-end communication range is extended far beyond the radio range of each individual node.
2. Topology
There are different types of nodes:
- Simple Nodes
- Proxy Nodes
- Relay Nodes
- Low-Power Nodes
- Friend Nodes
For more information about the node types, please refer to ST Bluetooth® LE-Mesh Application Note
[1].
A typical Bluetooth® LE mesh topology is illustrated in the figure below.
| Bluetooth® LE-mesh topology |
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3. Elements and Models
Each Bluetooth® LE-mesh node contains one or more elements, and each element can support different models.
| Bluetooth® LE-mesh node architecture |
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3.1. Elements
The elements define the functionalities of a single node, each element can be independently controlled.
3.2. Models
Models define the functionality of a specific element. Several models are defined by the Bluetooth® SIG, and many of them are deliberately defined as “generic” models, having potential use across a wide range of device types.
Refer to ST Bluetooth® LE-Mesh Application Note[1] for more details about Element and Models.
4. Provisioning
The process of adding a device into a Bluetooth® LE-mesh network, and configuring it, is called provisioning.
This process is started by a device called “provisioner”, which can be a smartphone with a Bluetooth® LE mesh application installed on it, or a mesh platform as STM35WBx5 line microcontroller. The provisioned device is now known as a node.
Refer to ST Bluetooth® LE-Mesh Application Note[1] for more details about provisioning steps.
5. Bluetooth® LE-Mesh with STM32WB
5.1. Node Feature Examples
STM32CubeWB MCU Package[2] provides 3 ST Bluetooth® LE-Mesh example covering the different types of Nodes.
- Bluetooth® LE-MeshLightingPRFNode project generates a basic Node supporting Proxy-Relay-Friend features, this project is the easier to handle and have a first approach of ST Bluetooth® LE-Mesh solution. See Proxy-Relay-Friend Lighting Example page for more information.
- Bluetooth® LE-MeshLightingLPN project generates a basic Low Power Node, which requires a Friend Node into the network to receive messages. See Friendship page for more information.
- Bluetooth® LE-MeshLightingProvisioner project generates a basic node managing ST proprietary solution of Embedded Provisioner, this Node can configurate itself and provision other nodes into the mesh network. See Embedded Provisioner page.
With these 3 types of project, user can create his own mesh network:
| Bluetooth® LE-mesh projects illustration |
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5.2. Node Model Demonstrations
STM32CubeWB MCU Package[2] also provides ST Bluetooth® LE-Mesh projects demonstrating different Models use cases:
- Sensor Model demonstration illustrate the Sensor Client and Server relation by implementing sensor request mechanism. The client send a sensor request to the server which reply with temperature of Time of Flight measurements. The demonstration setup and description can be found on the Sensor Server/Client demonstration page.
- Vendor Model project demonstrate how to define and use Vendor commands through a thermometer/temperature indicator system. The demonstration setup and description can be found on Vendor Model Demonstration page.
6. Certifications
ST Bluetooth® LEMesh 1.0 solution has been certified for STM32WB platforms.
Certifications are available on Bluetooth® SIG website:
- QDID 146387 - ST Bluetooth® LE mesh profile certification [3].
- QDID 151209 - ST Bluetooth® LE mesh server client model certification [4].
7. MOOC
STM32 Bluetooth® LE MESH Introduction
How to build Bluetooth Mesh network with STM32WB using STM32WB55Nucleo pack and its software package