A Quick Introduction to the Erbium (Er) REST Engine
===================================================
EXAMPLE FILES
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er-example-server.c: A RESTful server example showing how to use the REST layer to develop server-side applications (at the moment only CoAP is implemented for the REST Engine).
er-example-client.c: A CoAP client that polls the /actuators/toggle resource every 10 seconds and cycles through 4 resources on button press (target address is hard-coded).
er-plugtest-server.c: The server used for draft compliance testing at ETSI IoT CoAP Plugtest in Paris, France, March 2012 (configured for minimal-net).
PRELIMINARIES
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- Make sure rpl-border-router has the same stack and fits into mote memory:
You can disable RDC in border-router project-conf.h (not really required as BR keeps radio turned on).
#undef NETSTACK_CONF_RDC
#define NETSTACK_CONF_RDC nullrdc_driver
- For convenience, define the Cooja addresses in /etc/hosts
aaaa::0212:7401:0001:0101 cooja1
aaaa::0212:7402:0002:0202 cooja2
...
- Get the Copper (Cu) CoAP user-agent from https://addons.mozilla.org/en-US/firefox/addon/copper-270430/
- Optional: Save your target as default target
$ make TARGET=sky savetarget
COOJA HOWTO
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Server only:
1) $ make TARGET=cooja server-only.csc
2) Open new terminal
3) $ make connect-router-cooja
4) Start Copper and discover resources at coap://cooja2:5683/
- Choose "Click button on Sky 2" from the context menu of mote 2 (server) after requesting /test/separate
- Do the same when observing /test/event
With client:
1) $ make TARGET=cooja server-client.csc
2) Open new terminal
3) $ make connect-router-cooja
4) Wait until red LED toggles on mote 2 (server)
5) Choose "Click button on Sky 3" from the context menu of mote 3 (client) and watch serial output
TMOTES HOWTO
------------
Server:
1) Connect two Tmote Skys (check with $ make TARGET=sky sky-motelist)
2) $ make TARGET=sky er-example-server.upload MOTE=2
3) $ make TARGET=sky login MOTE=2
4) Press reset button, get address, abort with Ctrl+C:
Line: "Tentative link-local IPv6 address fe80:0000:0000:0000:____:____:____:____"
5) $ cd ../ipv6/rpl-border-router/
6) $ make TARGET=sky border-router.upload MOTE=1
7) $ make connect-router
For a BR tty other than USB0: $ make connect-router-port PORT=X
8) Start Copper and discover resources at coap://[aaaa::____:____:____:____]:5683/
Add a client:
1) Change the hard-coded server address in er-example-client.c to aaaa::____:____:____:____
2) Connect a third Tmote Sky
3) $ make TARGET=sky er-example-client.upload MOTE=3
MINIMAL-NET HOWTO
-----------------
With the target minimal-net you can test your CoAP applications without constraints, i.e., with large buffers, debug output, memory protection, etc.
The er-plugtest-server is thought for the minimal-net platform, as it requires an 1280-byte IP buffer and 1024-byte blocks.
1) $ make TARGET=minimal-net er-plugtest-server
2) $ sudo ./er-plugtest-server.minimal-net
3) Open new terminal
4) $ make connect-minimal
5) Start Copper and discover resources at coap://[fdfd::ff:fe00:10]:5683/
- You can enable the ETSI Plugtest menu in Copper's preferences
Under Windows/Cygwin, WPCAP might need a patch in <cygwin>\usr\include\w32api\in6addr.h:
21,23c21
< #ifdef __INSIDE_CYGWIN__
< uint32_t __s6_addr32[4];
< #endif
---
> u_int __s6_addr32[4];
36d33
< #ifdef __INSIDE_CYGWIN__
39d35
< #endif
DETAILS
-------
Erbium currently implements draft 13.
Central features are commented in er-example-server.c.
In general, apps/er-coap-13 supports:
* All draft 13 header options
* CON Retransmissions (note COAP_MAX_OPEN_TRANSACTIONS)
* Blockwise Transfers (note REST_MAX_CHUNK_SIZE, see er-plugtest-server.c for Block1 uploads)
* Separate Responses (no rest_set_pre_handler() required anymore, note coap_separate_accept(), _reject(), and _resume())
* Resource Discovery
* Observing Resources (see EVENT_ and PRERIODIC_RESOURCE, note COAP_MAX_OBSERVERS)
REST IMPLEMENTATIONS
--------------------
The Makefile uses WITH_COAP to configure different implementations for the Erbium (Er) REST Engine.
* WITH_COAP=13 uses Erbium CoAP 13 apps/er-coap-13/.
The default port for coap-13 is 5683.
* WITH_COAP=12 uses Erbium CoAP 12 apps/er-coap-12/.
The default port for coap-12 is 5683.
* WITH_COAP=7 uses Erbium CoAP 08 apps/er-coap-07/.
The default port for coap-07/-08 is 5683.
* WITH_COAP=3 uses Erbium CoAP 03 apps/er-coap-03/.
The default port for coap-03 is 61616.
er-coap-03 produces some warnings, as it not fully maintained anymore.
* WITH_COAP=0 is a stub to link an Erbium HTTP engine that uses the same resource abstraction (REST.x() functions and RESOURCE macros.
TODOs
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* Dedicated Observe buffers
* Optimize message struct variable access (directly access struct without copying)
* Observe client
* Multiple If-Match ETags
* (Message deduplication)
