reenable GPS + implement adaptiveDelay

api.h

@@ -11,12 +11,10 @@ class OsemApi {
   bool postMeasurement(String measurement, String sensorID) {
     //telnet.print("Connecting to API.. ");
     if (!client.connect(API_ENDPOINT, 443)) {
-      //Serial.println("connection failed");
       return false;
     }
     
     if (!client.verify(API_FINGERPRINT, API_ENDPOINT)) {
-      //Serial.println("certificate doesn't match");
       return false;
     }
     
@@ -29,12 +27,10 @@ class OsemApi {
     client << measurement;
 
     // read response
-    while (client.connected()) {
-      String line = client.readStringUntil('\n');
-      if (line == "\r") break;
-    }
-    Serial << "API-Server response: " << client.readString() << EOL;
-
+    if (!client.connected()) return false;
+    String line = client.readStringUntil('\r');
+    if (line != "HTTP/1.1 201 Created") return false;
+   
     return true;
   }
 };

config.h

@@ -20,3 +20,5 @@
 #define API_KEY "XXXXXXXXXXX"
 #define ID_BOX "57c7f3291421551100bf13c8"
 #define ID_SENSOR_WIFI "57c7f3291421551100bf13ca"
+
+#define MEASUREMENT_INTERVAL 10000

gps.h

@@ -66,14 +66,11 @@ class Gps {
   }
   
   /**
-   * return an iso8601 formatted datestring with the current time
+   * fill a char[20] with an iso8601 formatted date from now
    */
-  static char* getISODate() {
-    // TODO: check why we need to allocate that much storage for a 20 character string for Serial printing??
-    char result[100] = { 0 };
-    sprintf(result, "%04d-%02d-%02d-T%02d:%02d:%02dZ",
+  void getISODate(char* result) {
+    sprintf(result, "%04d-%02d-%02dT%02d:%02d:%02dZ",
       year(), month(), day(), hour(), minute(), second());
-    return result;
   }
 };
 

mobile-sensebox.ino

@@ -4,34 +4,16 @@
 #include "api.h"
 #include "storage.h"
 #include "TelnetPrint.h"
+#include "streampipe.h"
 
-#define DEBUG_OUT Serial
-//#define DEBUG_OUT telnet
+#define DEBUG_OUT telnet // debug output is available via telnet!
 
-//TelnetPrint telnet = TelnetPrint();
 Storage storage = Storage();
 Wifi wifi = Wifi();
+TelnetPrint telnet = TelnetPrint();
 OsemApi api = OsemApi();
 Gps gps = Gps();
 
-/* UTILS */
-void printState(WifiState wifiState) {
-  DEBUG_OUT.print("homeAvailable: ");
-  DEBUG_OUT.println(wifiState.homeAvailable);
-  DEBUG_OUT.print("numNetworks: ");
-  DEBUG_OUT.println(wifiState.numNetworks);
-  DEBUG_OUT.print("numUnencrypted: ");
-  DEBUG_OUT.println(wifiState.numUnencrypted);
-
-  DEBUG_OUT.print("lat: ");
-  //DEBUG_OUT.print(gps.getLocation().lat(), 6);
-  DEBUG_OUT.print(" lng: ");
-  //DEBUG_OUT.println(gps.getLocation().lng(), 6);
-
-  DEBUG_OUT.println(gps.getISODate());
-  DEBUG_OUT.println("");
-}
-
 bool storeMeasurement(float lat, float lng, float value, const char* timeStamp, const char* sensorID) {
   Measurement m;
   m.lat = lat;
@@ -43,26 +25,57 @@ bool storeMeasurement(float lat, float lng, float value, const char* timeStamp,
   return storage.add(m);
 }
 
+bool uploadMeasurements(const uint16_t maxUploads = 5) {
+  uint16_t uploadCount = 0;
+  String measure;
+  // only upload limited measures per cycle, to avoid long gaps in measurements
+  while (storage.size() && uploadCount++ < maxUploads) {
+    measure = storage.pop();
+    DEBUG_OUT << "Uploading measurement for " << measure;
+    if(!api.postMeasurement(measure.substring(API_KEY_LENGTH + 1), measure.substring(0, API_KEY_LENGTH))) {
+      DEBUG_OUT << "upload failed!" << EOL;
+      return false;
+    }
+    DEBUG_OUT << "success!" << EOL;
+  }
+  return true;       
+}
+
+// delay for a given duration (ms), rollover-safe implementation
+// offset may be a duration which has been "used up" before, so the delay is adaptive,
+// meaning that the interval of a adaptiveDelay() call is constant
+void adaptiveDelay(unsigned long ms, unsigned long offset = 0) {
+  unsigned long start = millis();
+  for (;;) {
+    // for some reason, operations have to be performed in this loop for
+    // proper operation, so we just do the polling to be done anyway
+    gps.pollGPS();
+    telnet.pollClients();
+  
+    unsigned long now = millis();
+    unsigned long elapsed = now - start + offset;
+    //DEBUG_OUT << elapsed << EOL;
+    if (elapsed >= ms) return;
+  }
+}
 
 /* MAIN ENTRY POINTS */
 void setup() {
-  DEBUG_OUT.begin(115200);
-
   size_t bytesFree = storage.begin();
-  //gps.begin();
+  gps.begin();
   wifi.begin();
   
+  // DEBUG: just for connection to telnet printer
   wifi.connect(WIFI_SSID, WIFI_PASS);
-
-  //delay(5000); // DEBUG oportunity to connect to network logger
+  DEBUG_OUT.begin();
+  delay(5000);
+  telnet.pollClients();
 
   // wait until we got a first fix from GPS, and thus an initial time
-  /*DEBUG_OUT.print("Getting GPS fix..");
+  DEBUG_OUT.print("Getting GPS fix..");
   while (!gps.updateLocation()) { DEBUG_OUT.print("."); }
-  DEBUG_OUT.print(" done! ");*/
-  DEBUG_OUT.println(gps.getISODate());
+  DEBUG_OUT.println(" done! ");
 
-  DEBUG_OUT.println("Setup done!\n");
   DEBUG_OUT.println("WiFi MAC            WiFi IP");
   DEBUG_OUT.print(WiFi.macAddress());
   DEBUG_OUT.print("   ");
@@ -71,38 +84,58 @@ void setup() {
   DEBUG_OUT.print("SPIFF bytes free: ");
   DEBUG_OUT.println(bytesFree);
   
-  digitalWrite(D9, HIGH); // DEBUG: integrated led? doesnt work
+  DEBUG_OUT.println("Setup done!\n");
 }
 
+unsigned long cycleStart;
+TinyGPSLocation loc;
+char dateString[20];
+
 void loop() {
-  //pollGPS();
-  //DEBUG_OUT.pollClients();
+  cycleStart = millis();
+  
+  //gps.pollGPS();
+  //telnet.pollClients();
+
+  // measure WiFi
   WifiState wifiState = wifi.scan(WIFI_SSID);
-  char* dateString = gps.getISODate();
 
-  // TODO: take other measurements (average them?)
-/*
+  // measure GPS
   if(!gps.updateLocation()) DEBUG_OUT.println("GPS timed out (location)");
   if(!gps.updateTime()) DEBUG_OUT.println("GPS timed out (time)");
-*/
+  loc = gps.getLocation();
+  gps.getISODate(dateString);
+
+  // print state
+  DEBUG_OUT << "homeAvailable:  " << wifiState.homeAvailable << EOL;
+  DEBUG_OUT << "numNetworks:    " << wifiState.numNetworks << EOL;
+  DEBUG_OUT << "numUnencrypted: " << wifiState.numUnencrypted << EOL;
+  DEBUG_OUT.print("lat: ");
+  DEBUG_OUT.print(loc.lat(), 6);
+  DEBUG_OUT.print(" lng: ");
+  DEBUG_OUT.println(loc.lng(), 6);
+  DEBUG_OUT << dateString << EOL;
 
   // write measurements to file
-  if (storeMeasurement(51.25345345, 7.89, wifiState.numNetworks, "2016-08-31T00:03:10Z", ID_SENSOR_WIFI)) {
-    DEBUG_OUT.print("measurement stored! storage size: ");
+  if (storeMeasurement(loc.lat(), loc.lng(), wifiState.numNetworks, dateString, ID_SENSOR_WIFI)) {
+    DEBUG_OUT.print("measurement (wifi) stored! storage size: ");
   } else {
-    DEBUG_OUT.print("measurement store failed! storage size: ");
+    DEBUG_OUT.print("measurement (wifi) store failed! storage size: ");
   }
   DEBUG_OUT.println(storage.size());
 
-  // TODO: connect to wifi, if available & not connected yet
-  
-  // then upload local data, remove from storage
-  while (storage.size()) {
-    String measure = storage.pop();
-    api.postMeasurement(measure.substring(API_KEY_LENGTH + 1), measure.substring(0, API_KEY_LENGTH));
+  // connect to wifi, if available & not connected yet
+  // once we are connected, upload (max) 3 stored measurements & free the storage
+  if (wifi.isConnected() || (wifiState.homeAvailable && wifi.connect(WIFI_SSID, WIFI_PASS)) ) {
+    uploadMeasurements(3);  
   }
+  
+  DEBUG_OUT << EOL;
 
-  printState(wifiState);
-  delay(5000);
+  // the measurement & upload cycle takes ~4 seconds, so lets we wait measure
+  // every 10secs in total
+  // run the loop every 10secs. using an adaptive delay
+  // IDEA: dont use time but distance interval? -> TinyGPSPlus::distanceBetween()
+  adaptiveDelay(MEASUREMENT_INTERVAL, millis() - cycleStart);
 }
 

wifi.h

@@ -50,5 +50,9 @@ class Wifi {
     //telnet.println(" timeout");
     return false;
   }
+
+  bool isConnected() {
+    return (WiFi.status() == WL_CONNECTED);
+  }
 };