Matter Linux Fabric Sync Example

An example application to implement the Fabric Synchronization feature and demonstrates the end-to-end Fabric Synchronization feature using dynamic endpoints.

Fabric Synchronization feature will facilitate the commissioning of end devices from one fabric to another without requiring user intervention for every end device. It defines mechanisms that can be used by multiple ecosystems/controllers to communicate with one another to simplify the experience for users.

This doc is tested on Ubuntu 22.04 LTS (aarch64)

Matter Linux Fabric Sync Example

Theory of Operation

Dynamic Endpoints

The Fabric-Sync Example makes use of Dynamic Endpoints. Current SDK support is limited for dynamic endpoints, since endpoints are typically defined (along with the clusters and attributes they contain) in a .zap file which then generates code and static structures to define the endpoints.

To support endpoints that are not statically defined, the ZCL attribute storage mechanisms will hold additional endpoint information for NUM_DYNAMIC_ENDPOINTS additional endpoints. These additional endpoint structures must be defined by the application and can change at runtime.

To facilitate the creation of these endpoint structures, several macros are defined:

DECLARE_DYNAMIC_ATTRIBUTE_LIST_BEGIN(attrListName) DECLARE_DYNAMIC_ATTRIBUTE(attId, attType, attSizeBytes, attrMask) DECLARE_DYNAMIC_ATTRIBUTE_LIST_END(clusterRevision)

These three macros are used to declare a list of attributes for use within a cluster. The declaration must begin with the DECLARE_DYNAMIC_ATTRIBUTE_LIST_BEGIN macro which will define the name of the allocated attribute structure. Each attribute is then added by the DECLARE_DYNAMIC_ATTRIBUTE macro. Finally, DECLARE_DYNAMIC_ATTRIBUTE_LIST_END macro should be used to close the definition.
All attributes defined with these macros will be configured as ATTRIBUTE_MASK_EXTERNAL_STORAGE in the ZCL database and therefore will rely on the application to maintain storage for the attribute. Consequently, reads or writes to these attributes must be handled within the application by the emberAfExternalAttributeWriteCallback and emberAfExternalAttributeReadCallback functions. See the bridge application's main.cpp for an example of this implementation.

DECLARE_DYNAMIC_CLUSTER_LIST_BEGIN(clusterListName) DECLARE_DYNAMIC_CLUSTER(clusterId, clusterAttrs, role, incomingCommands, outgoingCommands) DECLARE_DYNAMIC_CLUSTER_LIST_END

These three macros are used to declare a list of clusters for use within a endpoint. The declaration must begin with the DECLARE_DYNAMIC_CLUSTER_LIST_BEGIN macro which will define the name of the allocated cluster structure. Each cluster is then added by the DECLARE_DYNAMIC_CLUSTER macro referencing attribute list previously defined by the DECLARE_DYNAMIC_ATTRIBUTE... macros and the lists of incoming/outgoing commands terminated by kInvalidCommandId (or nullptr if there aren't any commands in the list). Finally, DECLARE_DYNAMIC_CLUSTER_LIST_END macro should be used to close the definition.

DECLARE_DYNAMIC_ENDPOINT(endpointName, clusterList)

This macro is used to declare an endpoint and its associated cluster list, which must be previously defined by the DECLARE_DYNAMIC_CLUSTER... macros.

Building

For Linux host example:

source scripts/activate.sh
./scripts/build/build_examples.py --target linux-x64-fabric-sync-no-ble build

For Raspberry Pi 4 example:

Pull Docker Images

docker pull ghcr.io/project-chip/chip-build-crosscompile:93

Run docker

docker run -it -v ~/connectedhomeip:/var/connectedhomeip ghcr.io/project-chip/chip-build-crosscompile:93 /bin/bash

Build

cd /var/connectedhomeip

git config --global --add safe.directory /var/connectedhomeip

./scripts/run_in_build_env.sh \
 "./scripts/build/build_examples.py \
    --target linux-arm64-fabric-sync-no-ble-clang \
    build"

Transfer the fabric-bridge-app binary to a Raspberry Pi

scp ./fabric-sync ubuntu@xxx.xxx.xxx.xxx:/home/ubuntu

Running the Complete Example on Ubuntu

Building
Follow Building section of this document.

Run Linux Fabric Sync Example App on two Linux machine E1 and E2

sudo rm -rf /tmp/chip_*
cd ~/connectedhomeip/
out/debug/fabric-sync

Initiate the FS Setup Process from E1 to E2

> app add-bridge 1 20202021 192.168.86.246 5540
Done
> New device with Node ID: 0000000000000001 has been successfully added.
A new device has been added on Endpoint: 2.

Verify Reverse Commissioning of the Fabric-Bridge from E1 on E2

> New device with Node ID: 0000000000000002 has been successfully added.

Pair Light Example to E2
Since Fabric-Bridge also functions as a Matter server, running it alongside the Light Example app on the same machine would cause conflicts. Therefore, you need to run the Matter Light Example app on a separate physical machine from the one hosting Fabric-Sync.
```
> app add-device 3 <setup-pin-code> <device-remote-ip> <device-remote-port>
```
After the device is successfully added, you will observe the following message on E2 with the newly assigned Node ID:
```
> New device with Node ID: 0x3 has been successfully added.
```
Additionally, you should also get notified when a new device is added to E2 from the E1:
```
> A new device is added on Endpoint 3.
```
Synchronize Light Example to E1
After the Light Example is successfully paired in E2, we can start to synchronize the light device to E1 using the new assigned dynamic endpointid on Ecosystem 2.
```
> app sync-device <endpointid>
```