Problems with Arduino datalogging

Projects Programming
1

Hello,
I have been developing a model rocket flight computer and have run into a problem with data logging. Some values in the file are insanely big like altitude, altitudeAGL, and temp. Why?
The file:

Time, X_ACC, Y_ACC, Z_ACC, X_GYRO, Y_GYRO, Z_GYRO, System_State, altitude, altitudeAGL, Pressure, Temp
4087,16,16164,-104,-188,46,-94,0,-536870912,1081485777,0,-1073329600
4251,-56,16360,-288,-253,46,-87,0,-536870912,1081485777,0,-1073329600
4414,44,16104,-240,-246,30,-85,0,536870912,1081485603,0,-1073307232
4577,128,16220,-300,-269,14,-106,0,536870912,1081485603,0,-1073307232
4741,152,16272,-308,-261,34,-97,0,536870912,1081485603,0,-1073307232
4904,8,16904,12332,-479,2733,-211,0,-2147483648,1081485526,0,-1073297424
5066,-396,16828,-2160,-650,-1327,24,0,-2147483648,1081485526,0,-1073297424
5230,64,16300,180,-398,-1331,-10,0,-2147483648,1081485526,0,-1073297424
5393,116,16244,-256,-447,6,-92,0,-1073741824,1081485547,0,-1073300144
5557,-56,16336,-104,-196,73,-80,0,-1073741824,1081485547,0,-1073300144
5720,-148,16056,-624,45,-1706,63,0,-1073741824,1081485547,0,-1073300144
5883,-1184,17320,1056,-1181,-9023,467,0,-2147483648,1081485381,0,-1073278864
6047,144,18632,-1208,-19455,-13386,-7410,0,-2147483648,1081485381,0,-1073278864
6209,-1008,13180,4300,-3171,-4019,14142,0,-2147483648,1081485381,0,-1073278864
6372,3772,15880,4584,4932,3372,-7082,0,-2147483648,1081485462,0,-1073289232
6536,-3300,13504,-600,651,-310,-4183,0,-2147483648,1081485462,0,-1073289232
6699,-84,15588,2872,-5409,-6715,3715,0,-2147483648,1081485462,0,-1073289232
6863,3756,13328,2724,-3010,-2074,1263,0,-2147483648,1081485462,0,-1073289232
7026,1668,15268,5100,-7072,-5330,899,0,-1610612736,1081485349,0,-1073274784
7189,524,15792,9888,-2900,1619,2438,0,-1610612736,1081485349,0,-1073274784
7351,4456,14616,6196,500,518,-489,0,-1610612736,1081485349,0,-1073274784
7515,4856,14368,6460,591,301,-894,0,1610612736,1081483412,0,-1073026816
7678,5272,15352,6912,2888,2702,-1779,0,1610612736,1081483412,0,-1073026816
7842,3348,15044,5880,-820,1084,-506,0,1610612736,1081483412,0,-1073026816
8005,2824,14752,6068,-771,-495,226,0,1610612736,1081483574,0,-1073047552
8169,4276,15296,5864,-1431,2007,-2672,0,1610612736,1081483574,0,-1073047552
8332,-880,18428,5660,4944,5493,-19010,0,1610612736,1081483574,0,-1073047552
8494,-6704,13196,3280,32767,20420,-1832,0,1610612736,1081483672,0,-1073060096
8658,1120,15404,-5616,1937,-5,14,0,1610612736,1081483672,0,-1073060096
8821,472,32767,-684,15772,19442,-5730,0,1610612736,1081483672,0,-1073060096
8984,-2748,26800,-2840,-20500,3960,-16385,1,1073741824,1081483800,0,-1073076464
9148,-4612,-18592,-5864,1624,527,15003,1,1073741824,1081483800,0,-1073076464
9311,-13164,-17256,-6164,1000,-6143,-5345,1,1073741824,1081483800,0,-1073076464
9474,2744,10796,10264,2791,-15808,-1057,1,1610612736,1081483851,0,-1073083008
9637,-760,16768,11468,-20592,-6521,3414,1,1610612736,1081483851,0,-1073083008
9801,1280,14496,6944,-885,-2251,-3926,1,1610612736,1081483851,0,-1073083008
9964,1176,16808,6324,3735,3883,1363,1,0,1081484056,0,-1073109200
10128,548,15696,5200,-51,-246,-303,1,0,1081484056,0,-1073109200
10291,792,14744,7208,-1379,-2736,-841,1,0,1081484056,0,-1073109200
10455,1480,14848,6316,-3187,-537,-1826,1,0,1081484056,0,-1073109200
10617,860,14944,7268,-223,415,-23,1,1610612736,1081483981,0,-1073099648
10781,1344,15348,6232,8584,6165,-135,1,1610612736,1081483981,0,-1073099648
10944,-80,16548,2700,6586,11561,-4667,1,1610612736,1081483981,0,-1073099648
11108,-1280,19244,852,6691,4215,3764,1,0,1081484105,0,-1073115472
11271,276,16492,656,-279,1644,785,1,0,1081484105,0,-1073115472
11435,456,15316,112,140,4789,-382,1,0,1081484105,0,-1073115472
11598,132,16224,0,-510,465,-116,1,1610612736,1081484143,0,-1073120384
11760,24,16252,200,-406,58,-119,1,1610612736,1081484143,0,-1073120384
11923,0,16328,96,-200,73,-96,1,1610612736,1081484143,0,-1073120384
12087,344,16036,-220,-489,-992,-125,1,-2147483648,1081484324,0,-1073143568
12250,712,16552,380,-372,-854,-101,1,-2147483648,1081484324,0,-1073143568
12414,716,16380,-216,-243,-1422,32,1,-2147483648,1081484324,0,-1073143568
12577,-1564,17048,1052,-3373,-4184,-2177,1,-1610612736,1081484309,0,-1073141664
12741,-396,16948,2364,-6696,-3344,-2852,1,-1610612736,1081484309,0,-1073141664
12915,-1396,12424,4984,1105,-8779,5588,1,-1610612736,1081484309,0,-1073141664
13079,-1388,13760,2756,18293,17234,-433,1,1610612736,1081484322,0,-1073143296
13245,2488,16652,4236,-2821,-5606,-1384,1,1610612736,1081484322,0,-1073143296
13409,-752,15928,9672,-2533,-260,947,1,1610612736,1081484322,0,-1073143296
13575,2540,15664,5896,-2243,1634,1609,1,-536870912,1081484281,0,-1073138112
13739,2352,14652,5692,-2157,285,-1109,1,-536870912,1081484281,0,-1073138112
13905,1880,14648,7252,149,1422,841,1,-536870912,1081484281,0,-1073138112
14068,2536,15348,7204,-610,439,-271,1,536870912,1081484644,0,-1073184480
14234,2884,14504,7508,580,-38,-910,1,536870912,1081484644,0,-1073184480
14397,2256,14804,6848,-34,-15,-786,1,536870912,1081484644,0,-1073184480
14563,2332,14728,7716,-294,23,-113,1,536870912,1081484644,0,-1073184480
14727,2764,15300,7232,417,303,-316,1,1073741824,1081485556,0,-1073301232
14893,3064,15020,5432,1158,1768,-1190,1,1073741824,1081485556,0,-1073301232
15057,1792,15340,6132,1613,639,-1068,1,1073741824,1081485556,0,-1073301232
15222,0,15608,4212,3214,437,-185,1,-1610612736,1081485609,0,-1073308064
15385,-176,16656,2288,1990,518,-93,1,-1610612736,1081485609,0,-1073308064
15551,-616,15456,824,1285,530,-41,1,-1610612736,1081485609,0,-1073308064
15715,392,16664,-144,456,-87,-229,1,0,1081485243,0,-1073261136
15881,440,16296,284,-212,-418,-67,1,0,1081485243,0,-1073261136
16045,-40,16068,456,-409,182,-68,1,0,1081485243,0,-1073261136
16209,-600,16768,-708,-2477,-4273,-2,1,536870912,1081485098,0,-1073242592
16372,108,16372,828,468,67,100,1,536870912,1081485098,0,-1073242592
16536,36,16384,-36,-330,41,-118,1,536870912,1081485098,0,-1073242592

The datalogging file:

#include <Arduino.h>
#include <SD.h>

File forzaFlightData;
const char filename[] = "forzaDataLog.txt";
extern int pressure;
extern int temp;
extern int altitude;
char buffer[128];
bool hasRun = false;
void SDInit()
{
    SD.begin(BUILTIN_SDCARD);
    if (!SD.begin(BUILTIN_SDCARD))
    {
        Serial.print("The SD card failed to initalize");
        while (1)
            ;
    }
    Serial.println("The SD card has been initalized.");
    if (SD.exists(filename))
    {
        SD.remove(filename);
    }
    forzaFlightData = SD.open(filename, FILE_WRITE);
    if (!hasRun)
    {
        if (forzaFlightData)
        {

            forzaFlightData.println("Time, X_ACC, Y_ACC, Z_ACC, X_GYRO, Y_GYRO, Z_GYRO, System_State, altitude, altitudeAGL, Pressure, Temp");
        }
        hasRun = true;
    }
    forzaFlightData.close();
}

void dataLog()
{
    forzaFlightData = SD.open(filename, FILE_WRITE);
    if (forzaFlightData)
    {
        sprintf(buffer, "%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d", millis(), ax, ay, az, gx, gy, gz, systemState, BMPAltitudeUpdate(), BMPAltitudeUpdate() - 357.4, BMPPressureUpdate(), BMPTempUpdate());
        forzaFlightData.println(buffer);
        // Serial.println(millis()); // just a lil debugging :)
        delay(100);
    }
    forzaFlightData.close();
}
void stopDataLog()
{
    forzaFlightData.close();
}

the BMP280 file:

#include <Arduino.h>
#include <Adafruit_BMP280.h>
#include <SPI.h>
#include <Wire.h>
#define BMP_SCK (13)
#define BMP_MISO (12)
#define BMP_MOSI (11)
#define BMP_CS (10)
Adafruit_BMP280 bmp(BMP_CS);
extern int systemState;
bool hitApogee;
extern int altitudeAGL;
void BMPInit()
{
    if (!bmp.begin())
    {
        Serial.print("Connection To Barometer Failed...");
    }
    Serial.println("Succesfully connected to BMP280...");
    bmp.setSampling(Adafruit_BMP280::MODE_NORMAL,  /* Operating Mode. */
                    Adafruit_BMP280::SAMPLING_X2,  /* Temp. oversampling */
                    Adafruit_BMP280::SAMPLING_X16, /* Pressure oversampling */
                    Adafruit_BMP280::FILTER_X16,   /* Filtering. */
                    Adafruit_BMP280::STANDBY_MS_500);
}

void printVals_BARO_x10()
{
    for (int i = 0; i < 10; i++)
    {
        Serial.println(bmp.readAltitude(1017.0));
        delay(500);
    }
}

float BMPPressureUpdate()
{
    return bmp.readPressure();
}
float BMPTempUpdate()
{
    return bmp.readTemperature();
}
float BMPAltitudeUpdate()
{
    return bmp.readAltitude(1017.0); // Adjust to local forecast!!
}
bool detectApogee()
{
    int currentAltitude = 0;
    if (systemState == 1)
    {
        int lastAltitude = currentAltitude;
        currentAltitude = BMPAltitudeUpdate();
        if (currentAltitude > lastAltitude)
        {
            return false;
        }
        else
        {
            systemState++;
            hitApogee = true;
            return true;
        }
    }
}
void detectLanding()
{
    if (systemState == 3 && hitApogee && altitudeAGL < 5)
    {
        systemState++;
    }
}

And the main.cpp file:

#include <Arduino.h>
#include <IMU6050.h>
#include <BARO280.h>
#include <GNC.h>
#include <State_Indication.h>
#include <System.h>
#include <pyro.h>
#include <datalog.h>
#include <SITL.h>
#include <TVC.h>
int systemState = 0;
extern int altitudeAGL = 0;
extern int altitude = 0;
extern int temp = 0;
extern int pressure = 0;
void setup()
{
    Serial.begin(9600);
    mpuInit();
    BMPInit();
    SDInit();
    TVCInitalize();
}

void loop()
{
    timeKeeper();
    State_Indication();
    navUpdate();
    dataLog();
    TVCCenter();

    if (systemState == 0) // Ground idle
    {
        allPyrosLow();
        detectLiftoff();
    }
    if (systemState == 1) // Ascent
    {
        detectApogee();
    }
    if (systemState == 2) // Ballistic descent
    {
        detectChutes();
    }
    if (systemState == 3) // Under chutes
    {
        detectLanding();
    }
    delay(50);
}
2

The insanely big values probably result from the print() method deciding that some variable should be converted as "long".

Big hint: these are always the 9th, 10th, and 12th numbers on a line, and the 11th is always zero.

Please explain how sprintf() deals with float values, in this line:

sprintf(buffer, "%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d", millis(), ax, ay, az, gx, gy, gz, systemState, BMPAltitudeUpdate(), BMPAltitudeUpdate() - 357.4, BMPPressureUpdate(), BMPTempUpdate());

BTW: what program is printing out the data, posted as "the file"?

3

%f not %d for floats

4

Except floats are not enabled for Arduino sprintf(). Use dtostrf() to convert the float to a string then %s for the placeholder in sprintf() format string.

5

I did not know that... thanks.

6

sprintf "%f" is enabled for some MCUs that can be programmed using the Arduino IDE, but the OP forgot to mention whatever it is they are using.

7

Turns out, this problem was caused by my poor understanding of the sprintf function.

Please explain how sprintf() deals with float values, in this line:

The answer is, it doesn't. That was the problem. I needed to use %f.
For anyone wondering, I'm using a Teensy 4.1 microcontroller from PJRC.
Thanks for the help!

8

Fortunately, the Teensy series is one in which sprintf("%f") is supported.

9

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