Fix for RX memory collision

LibAPRS/AX25.cpp

@@ -49,7 +49,11 @@ static void ax25_decode(AX25Ctx *ctx) {
     msg.len = ctx->frame_len - 2 - (buf - ctx->buf);
     msg.info = buf;
 
-    if (ctx->hook) ctx->hook(&msg);        
+    if (ctx->hook) {
+        cli();
+        ctx->hook(&msg);
+        sei();
+    }   
 
 }
 

LibAPRS/examples/Basic_usage/Basic_usage.ino

@@ -18,6 +18,9 @@
 // You always need to include this function. It will
 // get called by the library every time a packet is
 // received, so you can process incoming packets.
+//
+// If you are only interested in receiving, you should
+// just leave this function empty.
 // 
 // IMPORTANT! This function is called from within an
 // interrupt. That means that you should only do things