** !!! Under Construction !!! **
The demo exchanges only a simple message with the coap-server. But that is the groundwork for many distributed systems. Not only IoT.
CoAP follows the REST paradigm, also very wellknown by the users of the other representative, HTTP.
That comes with:
- URI / Uniform Resource Identifier
- standardized methods
- application specific payload
and enables to build powerful applications.
Both, the zephyr coap client and the Eclipse/Californium server supports you to use REST for your application.
This is usually the easier part. It requires that you are common enough with zephyr and the required tools. The zephyr coap client and net/coap.h contains the required documentation.
In many cases, it's also required to adapt the server. While this adaption itself isn't that hard, the pain comes with running an own server.
Californium's sandbox runs the cf-plugtest-server.
For your own setup a cf-cloud-demo-server is in preparation. It comes with configured DTLS graceful restart and a simple integrated HTTPs server to read the last posted data of your devices. A install script is available to speed up your first experience (see cf-cloud-demo-server - installation). This cloud-demo-server enables to add your own resources, see
For some applications the CoAP-S3-Proxy cf-s3-proxy-server simplifies the usage. That is in preparation as well. It comes with configured DTLS graceful restart and forwards the data send by the device to a S3 storage. It reads the user and device credentials from S3 or the file-system. Small and medium deployments benefits a lot from that. Finally, a Web-Browser javascript app displays that device data directly from S3 as text or chart. The reduces the need of an Web-Server to a HTTPs login servive, which is provided by the CoAP-S3-Proxy.
To run the server, it requires a machine to do so. Depending on the amount of expected devices and messages, Californium may run even on an Raspberry Pi (starting with 1 GB RAM), and also on small cloud vm's (1 or 2 v-cores, 2 GB RAM, usually offered from 10-30 Euro per month). That enables to run even small systems on a dedicated coap-server. The coap-server must have a stable ip-address and must be reachable from the public internet or you need an ip-tunnel to your mobile provider.
Californium comes with some examples installation instructions for either
To start with, usually the systemd-service may be easier. Using a cloud vm, cloud-init may speed up your installation a lot. Just install the unmodified plugtest-server and then update it to your modified version.
The cf-cloud-demo-server - installation installs the server also as systemd-service. A similiar installation will follow for the cf-s3-proxy-server.
** !!! Under Construction !!! **