microcoap_server: make app fully work with Copper

In its current state (and setup with radvd), the microcoap_example application will show up in Copper, but the CoAP requests won't reach the application. This commit fixes that and updates the README.

examples/microcoap_server/README.md

@@ -42,15 +42,18 @@ RIOT native hardware initialization complete.
 
 main(): This is RIOT! (Version: 2015.12-devel-632-g8f451-booze-add_conn_coap_example)
 RIOT microcoap example application
+Waiting for address autoconfiguration...
 Configured network interfaces:
-Iface  5   HWaddr: fa:bf:2b:01:9e:a3
-           MTU:1280  HL:64
+Iface  5   HWaddr: 96:3c:18:1e:26:f7
+
+           MTU:1500  HL:64  RTR  RTR_ADV
            Source address length: 6
            Link type: wired
            inet6 addr: ff02::1/128  scope: local [multicast]
-           inet6 addr: fe80::f8bf:2bff:fe01:9ea3/64  scope: local
-           inet6 addr: ff02::1:ff01:9ea3/128  scope: local [multicast]
+           inet6 addr: fe80::e42a:1aff:feca:10ec/64  scope: local
+           inet6 addr: ff02::1:ffca:10ec/128  scope: local [multicast]
            inet6 addr: ff02::2/128  scope: local [multicast]
+           inet6 addr: 2001:db8:1:0:e42a:1aff:feca:10ec/64  scope: global
 
 Waiting for incoming UDP packet...
 ```
@@ -80,22 +83,28 @@ getting it to work with RIOT requires a little setup.
 Make sure you've installed
 
 - The [Firefox Copper plugin](https://addons.mozilla.org/en-US/firefox/addon/copper-270430/)
-- The Router Advertisement Daemon (radvd) 
+- The Router Advertisement Daemon (radvd)
+
+And build the application again using `make`.
 
 Enter the following into your `/etc/radvd.conf` (if it doesn't exist yet, create one):
 
 ```
 interface tap0
 {
-        AdvSendAdvert on;
-        MinRtrAdvInterval 3;
-        MaxRtrAdvInterval 10;
-        prefix fc00::/64
-        {
-                AdvOnLink on;
-                AdvAutonomous on;
-                AdvRouterAddr off;
-        };
+    AdvSendAdvert on;
+
+    MinRtrAdvInterval 3;
+    MaxRtrAdvInterval 10;
+
+    AdvDefaultPreference low;
+
+    prefix 2001:db8:1:0::/64
+    {
+        AdvOnLink on;
+        AdvAutonomous on;
+        AdvRouterAddr off;
+    };
 };
 ```
 
@@ -104,13 +113,31 @@ interface tap0
 and run
 
 ```
-/bin/systemctl start radvd.service
+sudo radvd
+```
+
+Then, run the RIOT binary as usual:
+
+```
+make term
 ```
 
-Now you can enter
+Note that the output listing all configured interfaces contains a globally scoped
+address, which you can now use to reach the RIOT instance via Copper. To do so, enter this:
 
 ```
-coap://[fc00::1]/riot/board
+coap://[2001:db8:1:0:e42a:1aff:feca:10ec]/riot/board
 ```
 
-into your Firefox address bar.
+into your Firefox address bar, where you should replace `2001:db8:1:0:e42a:1aff:feca:10ec`
+with your RIOT instance's address marked as "scope: **global**".
+If you click the big green `GET` button, the word `native` should appear in the
+**Payload** text box at the center of the GUI.
+
+**If this doesn't work,** try manually adding a Global address to the tap0 interface:
+
+```
+sudo service radvd start
+sudo ip address add 2001:db8:1::a/64 dev tap0
+make term
+```

examples/microcoap_server/main.c

@@ -19,6 +19,7 @@
 
 #include <stdio.h>
 #include "msg.h"
+#include "xtimer.h"
 
 #define MAIN_QUEUE_SIZE     (8)
 static msg_t _main_msg_queue[MAIN_QUEUE_SIZE];
@@ -35,6 +36,9 @@ int main(void)
     /* microcoap_server uses conn which uses gnrc which needs a msg queue */
     msg_init_queue(_main_msg_queue, MAIN_QUEUE_SIZE);
 
+    puts("Waiting for address autoconfiguration...");
+    xtimer_sleep(3);
+
     /* print network addresses */
     puts("Configured network interfaces:");
     _netif_config(0, NULL);