examples/lorawan: update README

examples/lorawan/README.md

@@ -1,38 +1,46 @@
-LoRaWAN - OTAA
-==============
+## LoRaWAN
 
-Description
------------
+### Description
 
-This application shows a simple use case of LoRaWAN with RIOT.
+This application shows a basic LoRaWAN use-case with RIOT.
 
 By using the real time clock and low-power capabilities of a board, this
-application shows how to program a LoRaWAN Class A device using RIOT.
+application also shows how to program a LoRaWAN Class A device using RIOT.
 
-This application is using the Over-The-Air Activation (OTAA) procedure.
+By default, the application uses the Over-The-Air Activation (OTAA) procedure.
 
-Usage
------
+### Usage
+
+To join a LoRaWAN network using OTAA activation, edit the application
+`Makefile` and set your device information:
+
+    ACTIVATION_MODE ?= otaa
+    DEVEUI ?= 0000000000000000
+    APPEUI ?= 0000000000000000
+    APPKEY ?= 00000000000000000000000000000000
+
+To join a LoRaWAN network using ABP activation, edit the application
+`Makefile` and set your device and LoRaWAN application information:
+
+    ACTIVATION_MODE ?= abp
+    DEVADDR ?= 00000000
+    NWKSKEY ?= 00000000000000000000000000000000
+    APPSKEY ?= 00000000000000000000000000000000
+    RX2_FREQ ?= 869525000
+    RX2_DR ?= 3
 
 Simply build and flash the application for a ST B-L072Z-LRWAN1 board:
 
     make flash term
 
-Use the `BOARD`, `DRIVER` and `REGION` make variables to adapt the application
+Use the `BOARD`, `DRIVER` and `REGION` variables to adapt the application
 to your hardware setup and region of use:
 
 - `BOARD` can be one of the nucleo-64 boards
 - `DRIVER` can be either `sx1276` or `sx1272`
 - `REGION` can be `EU868`, `US915`, etc (see LoRaWAN regional parameters for
   details).
 
-ST Nucleo-64 can be used with mbed LoRa shields: there's one based on
+ST Nucleo-64 can be used as-is with mbed LoRa shields: there's one based on
 [the sx1276 radio](https://os.mbed.com/components/SX1276MB1xAS/) and one based
 on the [the sx1272 radio](https://os.mbed.com/components/SX1272MB2xAS/).
-
-Finally, to join a LoRaWAN network using OTAA activation, edit the application
-`Makefile` and set your device information:
-
-    DEVEUI ?= 0000000000000000
-    APPEUI ?= 0000000000000000
-    APPKEY ?= 00000000000000000000000000000000