Add raw data logging to SD card (#24)

src/vario/IMU.cpp

@@ -8,6 +8,8 @@
 #include <ICM_20948.h>
 #include "IMU.h"
 #include "Leaf_I2C.h"
+#include "log.h"
+#include "SDcard.h"
 
 #define DEBUG_IMU 0
 
@@ -63,6 +65,12 @@ void imu_update() {
     Serial.print(" z: ");
     Serial.println(az);
   }
+
+  if (logbook.dataFileStarted) {
+    String accelName = "accel,";
+    String accelEntry = accelName + String(at);
+    SDcard_writeData(accelEntry);
+  }
 }
 
 float IMU_getAccel() {

src/vario/SDcard.cpp

@@ -325,8 +325,41 @@ void SDcard_test(void) {
 }
 
 
+// Create & log flight test data for debugging and tuning
 
-// Creating and saving log files to SDCard
+String dataSaveDir = "/Data/";
+String currentDataFile;
+File dataFile;
+String dataFileName;
+
+bool SDcard_createDataFile(String filename) {  
+  dataFileName = filename;
+  createDir(SD_MMC, dataSaveDir.c_str());
+  currentDataFile = dataSaveDir + filename;
+
+  String header = "millis,sensor, value (lat), lng, alt m, speed mps, heading deg\n";
+
+  writeFile(SD_MMC, currentDataFile.c_str(), header.c_str());
+  dataFile = SD_MMC.open(currentDataFile.c_str(), FILE_APPEND);
+
+  // check if file was written properly, and return false if not
+  if (!dataFile) {
+    return false;
+  } else {
+    return true;
+  }
+}
+
+void SDcard_writeData(String data) {
+  String entry = String(millis()) + "," + data + "\n";
+  appendOpenFile(dataFile, entry.c_str());    
+}
+
+void SDcard_closeDataFile() {
+  dataFile.close();
+}
+
+// Creating and saving track log files to SDCard
 
 String saveDir = "/Tracks/";
 String currentTrackFile;

src/vario/SDcard.h

@@ -41,4 +41,8 @@ void appendOpenFile(File &file, const char * message);
 void SDcard_writeLogHeader(void);
 void SDcard_writeLogFooter(String trackName, String trackDescription);
 
+bool SDcard_createDataFile(String filename);
+void SDcard_writeData(String data);
+void SDcard_closeDataFile(void);
+
 #endif

src/vario/baro.cpp

@@ -9,6 +9,8 @@
 #include "Leaf_I2C.h"
 #include "tempRH.h"
 #include "buttons.h"
+#include "log.h"
+#include "SDcard.h"
 
 #define DEBUG_BARO 0  // flag for printing serial debugging messages
 
@@ -27,12 +29,14 @@
   LinearRegression<PRESSURE_FILTER_VALS_PREF> pressure_lr;
 
   // probably gonna delete these
+  /*
     #define VARIO_SENSITIVITY 3 // not sure what this is yet :)
 
     #define PfilterSize		6			// pressure alt filter values (minimum 1, max 10)
     int32_t varioVals[25];
     int32_t climbVals[31];
     int32_t climbSecVals[9];
+  */
 
 // Baro Values
   BARO baro;  // struct for common baro values we need all over the place
@@ -141,17 +145,7 @@
 // Device Management
 
   //Initialize the baro sensor
-  void baro_init(void)
-  {  
-    // probably don't need these
-          uint8_t i=0;
-        // initialize averaging arrays
-          for (i=0;i<31;i++) {
-            if (i<25) varioVals[i] = 0;
-            if (i<9) climbSecVals[i]=0;    
-            climbVals[i] = 0;
-          }
-
+  void baro_init(void) {  
     // recover saved altimeter setting
       if (ALT_SETTING > 28.0 && ALT_SETTING < 32.0)
         baro.altimeterSetting = ALT_SETTING;
@@ -316,7 +310,6 @@
   }
 // Device Management 
 
-
 // Device reading & data processing  
   void baro_calculatePressure() {
     // calculate temperature (in 100ths of degrees C, from -4000 to 8500)
@@ -350,8 +343,30 @@
 
     // calculate temperature compensated pressure (in 100ths of mbars)
       baro.pressure = ((uint64_t)D1_P * SENS1 / (int64_t)pow(2,21) - OFF1)/pow(2,15);
+
+    // record datapoint on SD card if datalogging is turned on
+      if (logbook.dataFileStarted) {
+        String baroName = "baro mb*100,";
+        String baroEntry = baroName + String(baro.pressure);
+        SDcard_writeData(baroEntry);
+      }
   }
 
+
+  // Filter Pressure Values
+  //
+  // To reduce noise, we perform a moving average of the last N data points.  We create an array of datapoints pressureFilterVals[] with size FILTER_VALS_MAX + 1, 
+  //     saving one spot [0] for an index/bookmark to where the next value should be stored.
+  // The value of the bookmark rises from 1 up to FILTER_VALS_MAX, then wraps around to 1 again, overwriting old data.  
+  // For proper behavior on startup, the each element of the array is loaded with the current (first) pressure reading.
+  //
+  // When filtering the pressure values, the most recent N values are summed up (from the bookmarked spot back to N spots before that), then divided by N to get the average.
+  //  (where N is presently PRESSURE_FILTER_VALS_PREF == FILTER_VALS_MAX)
+  // 
+  // TODO: Eventually we will support the user adjusting the sensitivity by reducing the size of PRESSURE_FILTER_VALS_PREF to average over fewer samples, if higher sensitivity (less noise reduction) is desired.
+  //
+  // NOTE: We have also explored performing a linear regeression on the last N samples to get a more accurate filtered value.  This is still in testing, and not currently being used in the code.
+  //
   void baro_filterPressure(void) {  
     // new way with regression:
       pressure_lr.update((double)millis(), (double)baro.alt);
@@ -410,7 +425,7 @@
       }
       baro.climbRateFiltered /= CLIMB_FILTER_VALS_PREF; // divide to get the filtered climb rate
 
-    // now calculate the longer-running average climb value
+    // now calculate the longer-running average climb value (this is a smoother, slower-changing value for things like glide ratio, etc)
     int32_t total_samples = CLIMB_AVERAGE * FILTER_VALS_MAX;   // CLIMB_AVERAGE seconds * 20 samples per second = total samples to average over
 
                             // current averaege    *   weighted by total samples (minus 1) + one more new sample     / total samples

src/vario/gps.cpp

@@ -12,6 +12,7 @@
 #include "settings.h"
 #include "log.h"
 #include "baro.h"
+#include "SDcard.h"
 
 #define DEBUG_GPS 0
 
@@ -223,6 +224,20 @@ void gps_update() {
   gps_updateSatList();
   gps_calculateGlideRatio();
 
+  if (logbook.dataFileStarted) {
+    String gpsName = "gps,";
+    String gpsEntryString = gpsName + 
+                            String(gps.location.lat(),8) + ',' +
+                            String(gps.location.lng(),8) + ',' +
+                            String(gps.altitude.meters()) + ',' +
+                            String(gps.speed.mps()) + ',' +
+                            String(gps.course.deg());
+
+    SDcard_writeData(gpsEntryString);
+  }
+
+
+
   /*
 
   Serial.print("Valid: ");

src/vario/log.cpp

@@ -10,6 +10,8 @@
 #include "SDcard.h"
 #include "tempRH.h"
 
+bool DATAFILE = true; // set to false to disable data logging to SDcard
+
 // Flight Timer
   uint32_t flightTimerSec = 0;
   bool flightTimerRunning = 0;
@@ -66,6 +68,11 @@ void log_update() {
       }
     }
 
+    // start the data file logging if needed
+    if (DATAFILE && !logbook.dataFileStarted) {
+      logbook.dataFileStarted = SDcard_createDataFile(log_createTestDataFileName());
+    }
+
     uint32_t logSave_time = micros();
 
     // save datapoints to the track
@@ -227,6 +234,12 @@ void log_update() {
         SDcard_writeLogFooter(log_createTrackFileName(), log_createTrackDescription());
         //TODO: other KML file additions; maybe adding description and min/max and other stuff
       }
+
+      //if a flight data file was started
+      if (logbook.dataFileStarted) {
+        logbook.dataFileStarted = false;
+        SDcard_closeDataFile();
+      }
     }
     flightTimerRunning = 0;
   }
@@ -409,6 +422,7 @@ String log_getKMLCoordinates() {
   return logPointStr;
 }
 
+// filename for Flight Track log file (GPS points every second)
 String log_createFileName() {  
   String fileTitle = "FlightTrack";
   String fileDate = String(gps_getLocalDate());
@@ -431,6 +445,21 @@ String log_createFileName() {
   return fileName;
 }
 
+// file name for Test Data file (all flight sensor data saved in real time -- for debugging and tuning purposes)
+String log_createTestDataFileName() {
+  String fileTitle = "TestData";
+  String fileDate = String(gps_getLocalDate());
+  int32_t timeInMinutes = (gps.time.hour()*60 + gps.time.minute() + 24*60 + TIME_ZONE) % (24*60);
+  uint8_t timeHours = timeInMinutes/60;
+  uint8_t timeMinutes = timeInMinutes % 60;
+  String fileTime = String(timeHours/10) + String(timeHours % 10) + String(timeMinutes / 10) + String(timeMinutes % 10);
+
+  String fileName = fileTitle + "_" + fileDate + "_" + fileTime + ".csv";
+  Serial.println(fileName);
+
+  return fileName;
+}
+
 String log_createTrackFileName() {
   Serial.print("creating track file name...");
   String trackname = "Flight Time: ";

src/vario/log.h

@@ -38,6 +38,9 @@
   String log_createTrackFileName(void);
   String log_createTrackDescription(void);
 
+// Test data file (all sensor values dumped realtime to csv)
+  String log_createTestDataFileName(void);
+
   void log_captureValues(void);
   void log_checkMinMaxValues(void);
   bool flightTimer_autoStop(void);
@@ -46,6 +49,7 @@
 // baro struct to hold most values 
 	struct LOGBOOK {
     bool flightTrackStarted = false;
+    bool dataFileStarted = false;
 
     int32_t alt = 0;
     int32_t alt_start = 0;