Clear WLAN WD so it does not interfere with Particle.connect()

system/src/system_network_internal.h

@@ -557,6 +557,8 @@ class ManagedNetworkInterface : public NetworkInterface
             WLAN_CONNECTING = 0;
             WLAN_CONNECTED = 0;
             WLAN_DHCP_PENDING = 0;
+            CLR_WLAN_WD();
+            LOG(INFO, "Clearing WLAN WD in disconnect()");
 
             cloud_disconnect(true, false, CLOUD_DISCONNECT_REASON_NETWORK_DISCONNECT);
             const auto diag = NetworkDiagnostics::instance();

user/tests/wiring/cell_connect_after_off/application.cpp

@@ -0,0 +1,14 @@
+#include "application.h"
+#include "unit-test/unit-test.h"
+
+// make clean all TEST=wiring/no_fixture PLATFORM=electron -s COMPILE_LTO=n program-dfu DEBUG_BUILD=y
+// make clean all TEST=wiring/no_fixture PLATFORM=electron -s COMPILE_LTO=n program-dfu DEBUG_BUILD=y USE_THREADING=y
+//
+ // Serial1LogHandler logHandler(115200, LOG_LEVEL_ALL, {
+  // { "comm", LOG_LEVEL_NONE }, // filter out comm messages
+  // { "system", LOG_LEVEL_INFO } // only info level for system messages
+ // });
+
+UNIT_TEST_APP();
+
+SYSTEM_THREAD(ENABLED);

user/tests/wiring/cell_connect_after_off/cellular_conn_after_off.cpp

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2018 Particle Industries, Inc.  All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "application.h"
+#include "unit-test/unit-test.h"
+
+#if Wiring_Cellular == 1
+
+// Global variable to indicate a connection attempt
+volatile int g_state_conn_attempt = 0;
+
+static void nwstatus_callback_handler(system_event_t ev, int param) {
+    if (param == network_status_connecting){
+        g_state_conn_attempt = 1;
+    }
+}
+
+test(CELLULAR_CONN_01_conn_after_off)
+{
+    // Connect to Particle cloud
+    Particle.connect();
+    delay(30000);
+    // Power off the cell radio
+    Cellular.off();
+    delay(60000);
+    // Callback handler for network_status
+    System.on(network_status, nwstatus_callback_handler);
+    // clear g_state_conn_attempt just-in-case
+    g_state_conn_attempt = 0;
+    // Check that Particle.connect() attempts to work after the delay
+    Particle.connect();
+    // Wait sometime for Particle.connect() to try
+    delay(30000);
+    // Verify that a connection attempt has been made
+    assertEqual(g_state_conn_attempt, 1);
+}
+
+#endif // Wiring_Cellular == 1

user/tests/wiring/cell_connect_after_off/readme.md

@@ -0,0 +1,5 @@
+The following illustrates the problem statement:
+> Keep antenna disconnected for this test
+1. With antenna disconnected, run `Particle.connect()`
+2. Run `Cellular.off()`
+3. After 60 sec, run `Particle.connect()` again, and verify that you see cellular AT traffic to turn on the modem or connect to the network.