diff --git a/tools/cooja/contiki_tests/crosslevel.js b/tools/cooja/contiki_tests/crosslevel.js
index 8131c3d64..68407db79 100644
--- a/tools/cooja/contiki_tests/crosslevel.js
+++ b/tools/cooja/contiki_tests/crosslevel.js
@@ -1,34 +1,25 @@
-/* Only handle receive messages */
-if (!msg.contains('received')) {
-  return;
+TIMEOUT(120000);
+
+var nr_packets = new Array();
+for (i=1; i <= 10; i++) {
+  nr_packets[i] = 0;
 }
 
-/* Log receiver */
-count = global.get("count_" + id);
-if (count == null) {
-  count = 0;
-}
-count++;
-global.put("count_" + id, count);
+while (true) {
 
-log.log("Node " + id + " received message: " + count + "\n");
+  /* Listen for receive notifications */
+  if (msg.contains('abc message received')) {
 
-/* Did all nodes (1-10) receive a message? */
-for (i = 1; i <= 10; i++) {
-  result = global.get("count_" + i);
-  if (result == null || result == 0) {
-    log.log("Node " + i + " did not yet receive a message\n");
-    return;
+    /* Log receiving node */
+    nr_packets[id] ++;
+    log.log("Node " + id + " received message: " + nr_packets[id] + "\n");
   }
-}
 
-/* Report test info */
-log.log("TEST INFO: ");
-for (i = 1; i <= 10; i++) {
-  result = global.get("count_" + i);
-  log.log(java.lang.Integer.toString(result) + " ");
-}
-log.log("\n");
+  /* Did all nodes (1-10) receive at least one message? */
+  for (i = 1; i <= 10; i++) {
+    if (nr_packets[id] < 1) break;
+    if (nr_packets[id] == 10) log.testOK();
+  }
 
-log.log("TEST OK\n"); /* Report test success */
-mote.getSimulation().getGUI().doQuit(false); /* Quit simulator (to end test run)*/
+  YIELD();
+}
diff --git a/tools/cooja/contiki_tests/rime_abc.js b/tools/cooja/contiki_tests/rime_abc.js
index cddc84d25..cd6c17ce5 100644
--- a/tools/cooja/contiki_tests/rime_abc.js
+++ b/tools/cooja/contiki_tests/rime_abc.js
@@ -1,28 +1,22 @@
-/* Only handle receive messages */
-if (!msg.contains('received')) {
-  return;
-}
+TIMEOUT(100000, log.log("Node 1: " + nr_packets[1] + ".\nNode 2: " + nr_packets[2] + ".\n"));
 
-/* Count received packets */
-result = global.get("recv_" + id);
-if (result == null) {
-  result = 0;
-}
-result++;
-global.put("recv_" + id, result);
-log.log(id + " received " + result + " messages\n");
+nr_packets = new Array();
+nr_packets[1] = 0;
+nr_packets[2] = 0;
 
-/* Did all nodes (1 and 2) receive a message? */
-for (i = 1; i <= 2; i++) {
-  result = global.get("recv_" + i);
-  if (result == null) {
-    return;
-  }
-  if (result < 30) {
-    return;
+while (true) {
+  /* Only handle receive messages */
+  YIELD_THEN_WAIT_UNTIL(msg.contains('received'));
+
+  /* Count received packets */
+  nr_packets[id]++;
+  //log.log("Node " + id + " received " + nr_packets[id] + " messages\n");
+
+  if (nr_packets[1] >= 30 && nr_packets[2] >= 30) {
+    log.log("Node 1: " + nr_packets[1] + ".\nNode 2: " + nr_packets[2] + ".\n");
+    log.testOK(); /* Report test success */
   }
+
 }
 
-log.log("Node 1 received " + global.get("recv_1") + " messages\n");
-log.log("Node 2 received " + global.get("recv_2") + " messages\n");
-log.testOK(); /* Report test success */
+
diff --git a/tools/cooja/contiki_tests/rime_rucb.js b/tools/cooja/contiki_tests/rime_rucb.js
index edcbc2705..d34689a34 100644
--- a/tools/cooja/contiki_tests/rime_rucb.js
+++ b/tools/cooja/contiki_tests/rime_rucb.js
@@ -1,4 +1,4 @@
-if (msg.startsWith('Completion time')) {
-  log.log(msg + "\n");
-  log.testOK(); /* Report test success and quit */
-}
+TIMEOUT(120000);
+
+WAIT_UNTIL(msg.startsWith('Completion time'));
+log.testOK();
diff --git a/tools/cooja/contiki_tests/rime_runicast.js b/tools/cooja/contiki_tests/rime_runicast.js
index 47fe8530e..f1f07e091 100644
--- a/tools/cooja/contiki_tests/rime_runicast.js
+++ b/tools/cooja/contiki_tests/rime_runicast.js
@@ -1,63 +1,46 @@
+TIMEOUT(120000);
+
+nr_recv = 0;
+nr_timedout = 0;
+nr_sent = 0;
+
+while (nr_sent < 10) {
 
 /* Count received packets */
 if (msg.contains('received')) {
-  result = global.get("recv");
-  if (result == null) {
-    result = 0;
-  }
-
-  result++;
-  global.put("recv", result);
-  log.log("Received packets count now: " + result + "\n");
+  nr_recv++;
+  log.log("Received packets count now: " + nr_recv + "\n");
 }
 
 /* Count timed out packets */
-if (msg.contains('timed out')) {
-  result = global.get("timeout");
-  if (result == null) {
-    result = 0;
-  }
-
-  result++;
-  global.put("timeout", result);
-  log.log("Timed out packets count now: " + result + "\n");
+else if (msg.contains('timed out')) {
+  nr_timedout++;
+  log.log("Timed out packets count now: " + nr_timedout + "\n");
 }
 
-
-
 /* Count sent packets */
-if (msg.contains('sent to')) {
-  result = global.get("sent");
-  if (result == null) {
-    result = 0;
-  }
-
-  result++;
-  global.put("sent", result);
-  log.log("Sent packets count now: " + result + "\n");
+else if (msg.contains('sent to')) {
+  nr_sent++;
+  log.log("Sent packets count now: " + nr_sent + "\n");
 }
 
-/* Look for test completion */
-countSent = global.get("sent");
-if (countSent >= 10) {
-
-  /* Make sure received counter matches sent counter */
-  countReceived = global.get("recv");
-  if (countReceived < countSent) {
-    log.log("Received < Sent: " + countReceived + " < " + countSent + "\n");
-    log.log("Received packets less than acked sent packets!\n");
-    log.testFailed();
-  }
-
-  /* Make sure some packets timed out (all from node 4) */
-  countTimedOut = global.get("timeout");
-  if (countTimedOut == null || countTimedOut < 2) {
-    log.log("Timed out: " + countTimedOut + "\n");
-    log.log("Too few packets timed out!\n");
-    log.testFailed();
-  }
-
-  log.log("Received / Sent: " + countReceived + " / " + countSent + "\n");
-  log.log("Timed out: " + countTimedOut + "\n");
-  log.testOK();
+YIELD();
 }
+
+/* Make sure received counter matches sent counter */
+if (nr_recv < nr_sent) {
+  log.log("Received < Sent: " + nr_recv + " < " + nr_sent + "\n");
+  log.log("Received packets less than acked sent packets!\n");
+  log.testFailed();
+}
+
+/* Make sure some packets timed out (all from node 4) */
+if (nr_timedout < 2) {
+  log.log("Timed out: " + nr_timedout + "\n");
+  log.log("Too few packets timed out!\n");
+  log.testFailed();
+}
+
+log.log("Received / Sent: " + nr_recv + " / " + nr_sent + "\n");
+log.log("Timed out: " + nr_timedout + "\n");
+log.testOK();
diff --git a/tools/cooja/contiki_tests/rime_trickle.js b/tools/cooja/contiki_tests/rime_trickle.js
index 80998ec45..8a4036d99 100644
--- a/tools/cooja/contiki_tests/rime_trickle.js
+++ b/tools/cooja/contiki_tests/rime_trickle.js
@@ -1,36 +1,25 @@
-/* Initiate trickle from node 1 by clicking button (once) */
-result = global.get("recv_1");
-if (result == null) {
-  if (id != 1) {
-    return;
-  }
+TIMEOUT(120000, log.log(nr_packets[1] + ", " + nr_packets[2] + ", " + nr_packets[3] + ", " + nr_packets[4] + ", " + nr_packets[5] + ", " + nr_packets[6] + ", " + nr_packets[7] + ", " + nr_packets[8] + ", " + nr_packets[9] + ", " + nr_packets[10] + "\n"));
 
-  if (!msg.contains('Starting')) {
-    return;
-  }
-
-  log.log("Clicking node 1 button\n");
-  mote.getInterfaces().getButton().clickButton()
-  global.put("recv_1", "ok");
-  return;
+nr_packets = new Array();
+for (i=1; i <= 10; i++) {
+  nr_packets[i] = 0;
 }
 
-/* Only handle receive messages */
-if (!msg.contains('received')) {
-  return;
-}
+WAIT_UNTIL(id == 1 && msg.contains('Starting'));
+log.log("Node 1 started. Clicking node button.\n");
+mote.getInterfaces().getButton().clickButton()
 
-/* Remember receiver */
-global.put("recv_" + id, "ok");
-log.log(id + " received a message\n");
+while (true) {
+  /* Only handle receive messages */
+  WAIT_UNTIL(msg.contains('received'));
 
-/* Did all nodes (1-10) receive a message? */
-for (i = 1; i <= 10; i++) {
-  result = global.get("recv_" + i);
-  if (result == null) {
-    return;
+  /* Remember receiving node */
+  log.log(id + " received a message\n");
+  nr_packets[id]++;
+
+  /* Did all nodes (2-10) receive a message? */
+  for (i = 2; i <= 10; i++) {
+    if (nr_packets[i] < 1) break;
+    if (i == 10) log.log("TEST OK\n"); /* Report test success */
   }
 }
-
-log.log("TEST OK\n"); /* Report test success */
-mote.getSimulation().getGUI().doQuit(false); /* Quit simulator (to end test run)*/
diff --git a/tools/cooja/contiki_tests/sky_coffee.js b/tools/cooja/contiki_tests/sky_coffee.js
index 4359054f2..8f454e10c 100644
--- a/tools/cooja/contiki_tests/sky_coffee.js
+++ b/tools/cooja/contiki_tests/sky_coffee.js
@@ -1,30 +1,31 @@
-if (msg.startsWith('Coffee file test: 0')) {
-  global.put("coffee_file_test", true);
-} else if (msg.startsWith('Coffee file test')) {
-  global.put("coffee_file_test", false);
-} else if (msg.startsWith('Coffee garbage collection test: 0')) {
-  global.put("coffee_gc_test", true);
-} else if (msg.startsWith('Coffee garbage collection test')) {
-  global.put("coffee_gc_test", false);
-}
-
-if (global.get("coffee_file_test") == null) {
-  //log.log("file test not finished yet\n");
-  return;
-}
-if (global.get("coffee_gc_test") == null) {
-  //log.log("gc test not finished yet\n");
-  return;
-}
-
-if (global.get("coffee_gc_test") == false) {
-  log.log("coffee garbage collection failed\n");
-  log.testFailed();
-}
-
-if (global.get("coffee_file_test") == false) {
-  log.log("coffee file test failed\n");
-  log.testFailed();
-}
-
-log.testOK();
+TIMEOUT(60000);
+
+fileOK = null;
+gcOK = null;
+
+while (fileOK == null || gcOK == null) {
+  YIELD();
+
+  if (msg.startsWith('Coffee file test: 0')) {
+    fileOK = true;
+  } else if (msg.startsWith('Coffee file test')) {
+    fileOK = false;
+  } else if (msg.startsWith('Coffee garbage collection test: 0')) {
+    gcOK = true;
+  } else if (msg.startsWith('Coffee garbage collection test')) {
+    gcOK = false;
+  }
+
+}
+
+if (gcOK == false) {
+  log.log("coffee garbage collection failed\n");
+}
+if (fileOK == false) {
+  log.log("coffee file test failed\n");
+}
+if (!fileOK || !gcOK) {
+  log.testFailed();
+} else {
+  log.testOK();
+}
diff --git a/tools/cooja/contiki_tests/sky_collect.js b/tools/cooja/contiki_tests/sky_collect.js
index bb669c711..9fdabf7ce 100644
--- a/tools/cooja/contiki_tests/sky_collect.js
+++ b/tools/cooja/contiki_tests/sky_collect.js
@@ -1,60 +1,51 @@
-/* Wait until all nodes have booted */
-if (msg.startsWith('Starting')) {
-  log.log("Node " + id + " booted\n");
-  global.put("boot_" + id, true);
+TIMEOUT(120000, log.log("received/node: " + count[1] + " " + count[2] + " " + count[3] + " " + count[4] + " " + count[5] + " " + count[6] + " " + count[7] + "\n"));
+
+/* Conf. */
+booted = new Array();
+count = new Array();
+nrNodes = 7;
+nodes_starting = true;
+for (i = 1; i <= nrNodes; i++) {
+  booted[i] = false;
+  count[i] = 0;
 }
-for (i = 1; i <= 7; i++) {
-  result = global.get("boot_" + i);
-  if (result == null || result == false) {
-    /*log.log("Node " + i + " did not yet boot\n");*/
-    return;
+
+/* Wait until all nodes have started */
+while (nodes_starting) {
+  WAIT_UNTIL(msg.startsWith('Starting'));
+  log.log("Node " + id + " booted\n");
+  booted[id] = true;
+
+  for (i = 1; i <= nrNodes; i++) {
+    if (!booted[i]) break;
+    if (i == nrNodes) nodes_starting = false;
   }
 }
 
 /* Create sink */
-result = global.get("created_sink");
-if (result == null || result == false) {
-  log.log("All nodes booted, creating sink at node " + id + "\n");
-  mote.getInterfaces().getButton().clickButton()
-  global.put("created_sink", true);
-  return;
-}
+log.log("All nodes booted, creating sink at node " + id + "\n");
+mote.getInterfaces().getButton().clickButton()
 
-/* Log incoming sensor data */
-source = msg.split(" ")[0];
-count = global.get("count_" + source);
-log.log("Got data from node " + source + "\n");
-if (count == null) {
-  count = 0;
-}
-count++;
-global.put("count_" + source, count);
+while (true) {
+  YIELD();
 
-/* Fail if any node has transmitted more than 20 packets */
-for (i = 1; i <= 7; i++) {
-  result = global.get("count_" + i);
-  if (result > 20) {
+  /* Count sensor data packets */
+  source = msg.split(" ")[0];
+  log.log("Got data from node " + source + "\n");
+  count[source]++;
 
-  log.log("FAILED: received/node: " + 
-    global.get("count_1") + " " +
-    global.get("count_2") + " " +
-    global.get("count_3") + " " +
-    global.get("count_4") + " " +
-    global.get("count_5") + " " +
-    global.get("count_6") + " " +
-    global.get("count_7") + "\n");
-    log.testFailed(); /* We are done! */
-    return;
+  /* Fail if any node has transmitted more than 20 packets */
+  for (i = 1; i <= nrNodes; i++) {
+    if (count[i] > 20) {
+      log.log("received/node: " + count[1] + " " + count[2] + " " + count[3] + " " + count[4] + " " + count[5] + " " + count[6] + " " + count[7] + "\n");
+      log.testFailed(); /* We are done! */
+    }
   }
-}
 
-/* Wait until we have received data from all nodes */
-for (i = 1; i <= 7; i++) {
-  result = global.get("count_" + i);
-  if (result < 5) {
-    /*log.log("Node " + i + " only sent " + result + " messages yet\n");*/
-    return;
+  /* Wait until we have received data from all nodes */
+  for (i = 1; i <= nrNodes; i++) {
+    if (count[i] < 5) break;
+    if (i == nrNodes) log.testOK();
   }
-}
 
-log.testOK(); /* We are done! */
+}
diff --git a/tools/cooja/contiki_tests/sky_helloworld.js b/tools/cooja/contiki_tests/sky_helloworld.js
index ef3a62343..4f3fd415d 100644
--- a/tools/cooja/contiki_tests/sky_helloworld.js
+++ b/tools/cooja/contiki_tests/sky_helloworld.js
@@ -1,7 +1,4 @@
-/* Script is called once for every node log output. */
-/* Input variables: Mote mote, int id, String msg. */
+TIMEOUT(2000, log.log("last message: " + msg + "\n"));
 
-if (msg.startsWith('Hello, world')) {
-  log.log('TEST OK\n'); /* Report test success */
-  mote.getSimulation().getGUI().doQuit(false); /* Quit simulator (to end test run)*/
-}
+WAIT_UNTIL(msg.equals('Hello, world'));
+log.testOK();
diff --git a/tools/cooja/contiki_tests/sky_shell_basic_commands.js b/tools/cooja/contiki_tests/sky_shell_basic_commands.js
index c0f78cb2e..e1866ca87 100644
--- a/tools/cooja/contiki_tests/sky_shell_basic_commands.js
+++ b/tools/cooja/contiki_tests/sky_shell_basic_commands.js
@@ -1,52 +1,15 @@
+TIMEOUT(2000, log.log("last message: " + msg + "\n"));
+
 /* Wait until node has booted */
-if (msg.startsWith('Starting')) {
-  log.log("Shell started\n");
-  global.put("started", true);
-}
-result = global.get("started");
-if (result == null || result == false) {
-  /*log.log("Shell did not yet start\n");*/
-  return;
-}
+WAIT_UNTIL(msg.startsWith('Starting'));
+log.log("Shell started\n");
 
-/* Send command ps */
-result = global.get("command_ps");
-if (result == null || result == false) {
-  log.log("Sending 'ps'\n");
-  global.put("command_ps", true);
-  node.write("ps");
-  return;
-}
+/* Test command: ps */
+node.write("ps");
+WAIT_UNTIL(msg.startsWith('Event timer'));
 
-/* Wait for ps response */
-if (msg.startsWith('Event timer')) {
-  log.log("Reponse from 'ps'\n");
-  global.put("response_ps", true);
-}
-result = global.get("response_ps");
-if (result == null || result == false) {
-  /*log.log("Waiting for 'ps' response\n");*/
-  return;
-}
+/* Test command: help */
+node.write("help");
+WAIT_UNTIL(msg.startsWith('write <filename>'));
 
-/* Send command help */
-result = global.get("command_help");
-if (result == null || result == false) {
-  log.log("Sending 'help'\n");
-  global.put("command_help", true);
-  node.write("help");
-  return;
-}
-
-/* Wait for help response */
-if (msg.startsWith('write <filename>')) {
-  log.log("Reponse from 'help'\n");
-  global.put("response_help", true);
-}
-result = global.get("response_help");
-if (result == null || result == false) {
-  /*log.log("Waiting for 'help' response\n");*/
-  return;
-}
-
-log.testOK(); /* We are done! */
\ No newline at end of file
+log.testOK(); /* We are done! */
diff --git a/tools/cooja/contiki_tests/sky_shell_compilation_test.js b/tools/cooja/contiki_tests/sky_shell_compilation_test.js
index d935b627c..b7fb0cf6a 100644
--- a/tools/cooja/contiki_tests/sky_shell_compilation_test.js
+++ b/tools/cooja/contiki_tests/sky_shell_compilation_test.js
@@ -1,9 +1,4 @@
-/* Script is called once for every node log output. */
-/* Input variables: Mote mote, int id, String msg. */
+TIMEOUT(2000, log.log("last message: " + msg + "\n"));
 
-/* Contiki test script example */
-if (msg.startsWith('Contiki')) {
-  log.testOK(); /* Report test success */
-} else {
-  log.testFailed(); /* Report test failure */
-}
+WAIT_UNTIL(msg.startsWith('Contiki'));
+log.testOK();