Improve tests

tests/api_receivet0_eth0_1s1r/receiver.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python
+
+def receivet(node,timeout):
+    ##### Simple receive
+    code, data=node.receivet("eth0",timeout)
+    msg="Received: "+data if code == 0 else "Receive failed code="+str(code)
+    node.log(msg)
+
+def execute(api):
+    # Should not works since communication start at t=0s
+    receivet(api,0)
+    api.wait(1)
+    # Now communication started
+    receivet(api,0) # Should work (no timeout error)