feat: Implement endpoint_diagnose app

Record the signal strength, GPS data and time in log.

TODO: Get the correct time with the consideration of time zone.

Related to #688.

endpoint/endpoint_diagnose.adef

@@ -0,0 +1,20 @@
+executables:
+{
+    endpoint_diagnose = ( endpoint_diagnoseComp )
+}
+
+processes:
+{
+    run:
+    {
+        (endpoint_diagnose)
+    }
+}
+
+bindings:
+{
+    endpoint_diagnose.endpoint_diagnoseComp.le_gnss -> positioningService.le_gnss
+    endpoint_diagnose.endpoint_diagnoseComp.le_mrc -> modemService.le_mrc
+}
+
+start: manual

endpoint/endpoint_diagnoseComp/Component.cdef

@@ -0,0 +1,18 @@
+requires:
+{
+    api:
+    {
+        modemServices/le_mrc.api
+        positioning/le_gnss.api
+    }
+}
+
+sources:
+{
+    endpoint_diagnose.c
+}
+
+cflags:
+{
+    -g -O0
+}

endpoint/endpoint_diagnoseComp/endpoint_diagnose.c

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2019-2020 BiiLabs Co., Ltd. and Contributors
+ * All Rights Reserved.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the MIT license. A copy of the license can be found in the file
+ * "LICENSE" at the root of this distribution.
+ */
+
+#include "le_gnss_interface.h"
+#include "le_mrc_interface.h"
+#include "legato.h"
+
+static void hardware_logging(le_timer_Ref_t timer) {
+  static char time_str[30];
+  static size_t copied_bytes = 0;
+  static int32_t latitude = 0, longitude = 0, accuracy = 0;
+  static uint32_t quality = 0;
+  static le_gnss_SampleRef_t position_sample;
+  static le_result_t result;
+
+  // Signal strength
+  result = le_mrc_GetSignalQual(&quality);
+  switch (result) {
+    case LE_OK:
+      LE_INFO("Signal strength: %d\n", quality);
+      break;
+    default:
+      LE_ERROR("Fail to get signal strength\n");
+      break;
+  }
+
+  // GPS
+  position_sample = le_gnss_GetLastSampleRef();
+  result = le_gnss_GetLocation(position_sample, &latitude, &longitude, &accuracy);
+  switch (result) {
+    case LE_OK:
+      LE_INFO("Latitude: %lf, Longitude: %lf, Horizontal accuracy: %d\n", (double)latitude / 1000000,
+              (double)longitude / 1000000, accuracy);
+      break;
+    case LE_FAULT:
+      LE_ERROR("Fail to get location data\n");
+      break;
+    case LE_OUT_OF_RANGE:
+      LE_ERROR("At least one retrieved value is invalid (set to INT32_MAX)\n");
+      LE_INFO("Latitude: %lf, Longitude: %lf, Horizontal accuracy: %d\n", (double)latitude / 1000000,
+              (double)longitude / 1000000, accuracy);
+      break;
+    default:
+      break;
+  }
+
+  // Time
+  result = le_clk_GetLocalDateTimeString(LE_CLK_STRING_FORMAT_DATE_TIME, time_str, sizeof(time_str), &copied_bytes);
+  switch (result) {
+    case LE_OK:
+      LE_INFO("Time: %s\n", time_str);
+      break;
+    case LE_OVERFLOW:
+      LE_ERROR("Overflow of time string\n");
+      break;
+    default:
+      break;
+  }
+}
+
+COMPONENT_INIT {
+  le_timer_Ref_t timer;
+  le_clk_Time_t interval = {3 /*sec*/, 0 /*usec*/};
+  le_gnss_State_t gnss_state;
+
+  // GPS state checking and activation
+  gnss_state = le_gnss_GetState();
+  if (gnss_state != LE_GNSS_STATE_ACTIVE) {
+    le_gnss_Start();
+    le_gnss_Enable();
+  }
+
+  // Timer for hardware logging
+  timer = le_timer_Create("diagnose_timer");
+  le_timer_SetInterval(timer, interval);
+  le_timer_SetRepeat(timer, 0);
+  le_timer_SetHandler(timer, hardware_logging);
+  le_timer_Start(timer);
+}

endpoint/endpoint_diagnoseComp/endpoint_diagnose.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2019-2020 BiiLabs Co., Ltd. and Contributors
+ * All Rights Reserved.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the MIT license. A copy of the license can be found in the file
+ * "LICENSE" at the root of this distribution.
+ */
+
+#ifndef ENDPOINT_DIAGNOSE_H
+#define ENDPOINT_DIAGNOSE_H
+
+/**
+ * @file endpoint/endpoint_diagnoseComp/endpoint_diagnose.h
+ */
+
+/**
+ * @brief Log the information from hardware
+ *
+ * @param[in] timer The timer of the function. It would be passed by the timer API le_timer_SetHandler().
+ */
+static void hardware_logging(le_timer_Ref_t timer);
+
+#endif  // ENDPOINT_DIAGNOSE_H