Host application for EZSP NCP to act as ZigBee Router

This software lets you use an EZSP NCP, aka USB/Network ZigBee controller with a Silicon Labs chip as a router. Normally one achieves this by flashing a different firmware into the chip, one that is designed to work standalone as a ZigBee router. However in cases where that firmware is hard to find, or you want to expose some values like "Host CPU temperature", "Host Uptime", or even adding a reset button to restart the server connected to the stick, this is the only way to do it.

Why using the GSDK? Why not zigpy?

Mainly because I want to run these on ZigBee IP hubs for which the router firmware is not available. To run this software on the hub (a MIPS CPU with very little RAM) there was no other alternative, bellows and zigpy both are python programs, and running python is impossible on these SOCs. My only alternative was C, and with a limited set of compiler features.

The only other C/C++ alternative I could find is libezsp, but it doesn't seem to be maintained or have support for any ZCL features.

Intializing project from GSDK and building

In the gsdk directory you'll find a Dockerfile to build the GSDK image. This image contains the appropriate environment and binaries used to generate the projects in the GSDK (also in the image). The main three components are:

1. GSDK
2. slc-cli: CLI program to deal with the Simplicity Studio files without actually using Simplicity Studio.
3. ZAP: Program to configure the ZCL components for the program.

Like any other docker image, you can build it with docker build -t . "$IMAGE_NAME" from the gsdk directory.

With the image built, the project can be generated using the gen_project.sh script, passing it the name of the image built before, the directory with patches you want to apply, and the docker command to use (could use podman here). For example:

./gsdk/gen_project.sh "$IMAGE_NAME" patches/orvibo-minihub/ sudo docker

This same script can be re-run in case you modified something on the project file or ZAP files (to be tested).

Once the project has been initialized and all templates rendered, you can build it using make -f ZigbeeMinimalHost.Makefile from the src/ directory.

Notes

The changes made to the default template can be found in the patches directory.

Issues with my SOC SDK

The ancient version of GCC I'm using with these hubs has some problems:

1. Doesn't allow for typedef redefinitions, modern versions do
2. No support for _Static_assert
3. sys/ttydefaults.h isn't included

Adding callbacks

You can add callbacks (noted nowhere in the documentation) by editing the project .slcp file as one by the 00-add-callbacks.patch to find all callback names run the following command:

cd "$GSDK_DIR"
grep "'callback_type'" \
./protocol/zigbee/app/framework/common/template/zigbee_stack_callback_dispatcher.h.jinja