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subframe and temp, hum calcs

pull/62/head
michael carter 2021-02-08 17:45:17 +00:00
rodzic 8e6d953e60
commit 0304e4ea32
2 zmienionych plików z 312 dodań i 0 usunięć
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309
libraries/SondeLib/RS41.cpp
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@ -17,6 +17,128 @@
static byte data[800];
static int dpos = 0;
static byte subframe[51*16]; // 816 subframe bytes
static bool subframeReceived[51] = { false }; // do we have data for row
static bool subframeComplete = false; // is the subframe complete
static bool validExternalTemperature = false; // have received all the calibration frames for the external temperature
static bool validHumidity = false; // have received all the calibration frames for the humidity
static bool validRAExternalTemperature = false; // have received all the calibration frames for the external temperature
static bool validRAHumidity = false; // have received all the calibration frames for the humidity
// whole 51 row frame as C structure
// taken from https://github.com/einergehtnochrein/ra-firmware
union subframeBuffer {
byte rawData[51*16];
struct __attribute__((__packed__)) {
uint16_t crc16; /* CRC16 CCITT Checksum over range 0x002...0x31F */
uint16_t frequency; /* 0x002: TX is on 400 MHz + (frequency / 64) * 10 kHz */
uint8_t startupTxPower; /* 0x004: TX power level at startup (1...7) */
uint8_t reserved005;
uint8_t reserved006;
uint16_t reserved007; /* 0x007: ?? (some bitfield) [0],[1],[2],[3]. Init value = 0xE */
uint16_t reserved009; /* 0x009: ? */
uint8_t reserved00B;
uint8_t reserved00C;
uint8_t serial[8]; /* 0x00D: Sonde ID, 8 char, not terminated */
uint16_t firmwareVersion; /* 0x015: 10000*major + 100*minor + patch*/
uint16_t reserved017;
uint16_t minHeight4Flight; /* 0x019: Height (meter above ground) where flight mode begins */
uint8_t lowBatteryThreshold100mV; /* 0x01B: (Default=18) Shutdown if battery voltage below this
threshold for some time (10s ?)
*/
uint8_t nfcDetectorThreshold; /* 0x01C: NFC detector threshold [25mV] (Default: 0x05 = 125mV) */
uint8_t reserved01D; /* 0x01D: ?? (Init value = 0xB4) */
uint8_t reserved01E; /* 0x01E: ?? (Init value = 0x3C) */
uint16_t reserved01F;
int8_t refTemperatureThreshold; /* 0x021: Reference temperature threshold [°C] */
uint8_t reserved022;
uint16_t reserved023;
uint16_t reserved025;
int16_t flightKillFrames; /* 0x027: Number of frames in flight until kill (-1 = disabled) */
uint16_t reserved029; /* 0x029: ? (Init value = 0) */
uint8_t burstKill; /* 0x02B: Burst kill (0=disabled, 1=enabled) */
uint8_t reserved02C;
uint8_t reserved02D;
uint16_t reserved02E;
uint16_t reserved030;
uint8_t reserved032;
uint16_t reserved033;
uint16_t reserved035;
uint16_t reserved037;
uint16_t reserved039; /* 0x039: */
uint8_t reserved03B; /* 0x03B: */
uint8_t reserved03C; /* 0x03C: */
float refResistorLow; /* 0x03D: Reference resistor low (750 Ohms) */
float refResistorHigh; /* 0x041: Reference resistor high (1100 Ohms) */
float refCapLow; /* 0x045: Reference capacitance low (0) */
float refCapHigh; /* 0x049: Reference capacitance high (47 pF) */
float taylorT[3]; /* 0x04D: Tayor coefficients for main temperature calculation */
float calT; /* 0x059: Calibration factor for main sensor */
float polyT[6]; /* 0x05D: */
float calibU[2]; /* 0x075: Calibration coefficients for humidity sensor */
float matrixU[7][6]; /* 0x07D: Matrix for humidity sensor RH calculation */
float taylorTU[3]; /* 0x125: Coefficients for U sensor temperature calculation */
float calTU; /* 0x131: Calibration factor for U temperature sensor */
float polyTrh[6]; /* 0x135: */
uint8_t reserved14D; /* 0x14D: */
uint32_t reserved14E; /* 0x14E: */
float f152;
uint8_t u156;
float f157; /* 0x157: ?? (Initialized by same value as calibU) */
uint8_t reserved15B[0x160-0x15B];
float f160[35];
uint8_t startIWDG; /* 0x1EC: If ==0 or ==2: Watchdog IWDG will not be started */
uint8_t parameterSetupDone; /* 0x1ED: Set (!=0) if parameter setup was done */
uint8_t reserved1EE;
uint8_t reserved1EF;
float f1F0[8];
float pressureLaunchSite[2]; /* 0x210: Pressure [hPa] at launch site */
struct {
char variant[10]; /* 0x218: Sonde variant (e.g. "RS41-SG") */
uint8_t mainboard[10]; /* 0x222: Name of mainboard (e.g. "RSM412") */
} names;
struct {
uint8_t mainboard[9]; /* 0x22C: Serial number of mainboard (e.g. "L1123553") */
uint8_t text235[12]; /* 0x235: "0000000000" */
uint16_t reserved241; /* 0x241: */
uint8_t pressureSensor[8]; /* 0x243: Serial number of pressure sensor (e.g. "N1310487") */
uint16_t reserved24B; /* 0x24B: */
} serials;
uint16_t reserved24D; /* 0x24D: */
uint8_t reserved24F;
uint8_t reserved250;
uint16_t reserved251; /* 0x251: (Init value = 0x21A = 538) */
uint8_t xdataUartBaud; /* 0x253: 1=9k6, 2=19k2, 3=38k4, 4=57k6, 5=115k2 */
uint8_t reserved254;
float cpuTempSensorVoltageAt25deg; /* 0x255: CPU temperature sensor voltage at 25°C */
uint8_t reserved259;
uint8_t reserved25A[0x25E -0x25A];
float matrixP[18]; /* 0x25E: Coefficients for pressure sensor polynomial */
float f2A6[17];
uint8_t reserved2EA[0x2FA-0x2EA];
uint16_t halfword2FA[9];
float reserved30C;
float reserved310; /* 0x310: */
uint8_t reserved314; /* 0x314: */
uint8_t reserved315; /* 0x315: */
int16_t burstKillFrames; /* 0x316: Number of active frames after burst kill */
uint8_t reserved318[0x320-0x318];
/* This is fragment 50. It only uses 14 valid bytes! */
int16_t killCountdown; /* 0x320: Counts frames remaining until kill (-1 = inactive) */
uint8_t reserved322[6];
int8_t intTemperatureCpu; /* 0x328: Temperature [°C] of CPU */
int8_t intTemperatureRadio; /* 0x329: Temperature [°C] of radio chip */
int8_t reserved32A; /* 0x32A: */
uint8_t reserved32B; /* 0x32B: */
uint8_t reserved32C; /* 0x32C: ? (the sum of two slow 8-bit counters) */
uint8_t reserved32D; /* 0x32D: ? (the sum of two slow 8-bit counters) */
} value;
} calibration;
static uint16_t CRCTAB[256];
#define X2C_DIVR(a, b) ((b) != 0.0f ? (a)/(b) : (a))
@ -251,6 +373,11 @@ static int32_t getint32(const byte frame[], uint32_t frame_len,
return (int32_t)n;
} /* end getint32() */
static uint32_t getint24(const byte frame[], uint32_t frame_len, uint32_t p) { // 24bit unsigned int
uint32_t val24 = 0;
val24 = frame[p] | (frame[p+1]<<8) | (frame[p+2]<<16);
return val24;
}
static uint32_t getcard16(const byte frame[], uint32_t frame_len,
uint32_t p)
@ -379,7 +506,124 @@ static void posrs41(const byte b[], uint32_t b_len, uint32_t p)
sonde.si()->validPos = 0x7f;
} /* end posrs41() */
void ProcessSubframe( byte subframeBytes[16], int subframeNumber ) {
// the total subframe consists of 51 rows, each row 16 bytes
// based on https://github.com/bazjo/RS41_Decoding/tree/master/RS41-SGP#Subframe
memcpy( calibration.rawData+16*subframeNumber, subframeBytes, 16);
subframeReceived[subframeNumber] = true; // mark this row of the total subframe as complete
#if 0
Serial.printf("subframe number: 0x%02X\n", subframeNumber );
Serial.print("subframe values: ");
for ( int i = 0; i < 16; i++ ) {
Serial.printf( "%02X ", subframeBytes[i] );
}
Serial.println();
Serial.println("Full subframe");
for ( int j = 0; j<51; j++ ) {
Serial.printf("%03X ", j*16);
for ( int i = 0; i < 16; i++ ) {
Serial.printf( "%02X ", subframe[j*16+i] );
}
Serial.println();
}
Serial.println();
#endif
}
/* Find the water vapor saturation pressure for a given temperature.
* Uses the Hyland and Wexler equation with coefficients for T < 0°C.
*/
// taken from https://github.com/einergehtnochrein/ra-firmware
static float _RS41_waterVaporSaturationPressure (float Tcelsius)
{
/* Convert to Kelvin */
float T = Tcelsius + 273.15f;
/* Apply some correction magic */
T = 0
- 0.4931358f
+ (1.0f + 4.61e-3f) * T
- 1.3746454e-5f * T * T
+ 1.2743214e-8f * T * T * T
;
/* Plug into H+W equation */
float p = expf(-5800.2206f / T
+ 1.3914993f
+ 6.5459673f * logf(T)
- 4.8640239e-2f * T
+ 4.1764768e-5f * T * T
- 1.4452093e-8f * T * T * T
);
/* Scale result to hPa */
return p / 100.0f;
}
// taken from https://github.com/einergehtnochrein/ra-firmware
float GetRATemp( uint32_t measuredCurrent, uint32_t refMin, uint32_t refMax, float calT, float taylorT[3], float polyT[6] ) {
/* Reference values for temperature are two known resistors.
* From that we can derive the resistance of the sensor.
*/
float current = float(measuredCurrent - refMin) / float(refMax - refMin);
float res = calibration.value.refResistorLow
+ (calibration.value.refResistorHigh - calibration.value.refResistorLow) * current;
float x = res * calT;
float Tuncal = 0
+ taylorT[0]
+ taylorT[1] * x
+ taylorT[2] * x * x;
/* Apply calibration polynomial */
float temperature =
Tuncal + polyT[0]
+ polyT[1] * Tuncal
+ polyT[2] * Tuncal * Tuncal
+ polyT[3] * Tuncal * Tuncal * Tuncal
+ polyT[4] * Tuncal * Tuncal * Tuncal * Tuncal
+ polyT[5] * Tuncal * Tuncal * Tuncal * Tuncal * Tuncal;
return temperature;
}
// taken from https://github.com/einergehtnochrein/ra-firmware
float GetRAHumidity( uint32_t humCurrent, uint32_t humMin, uint32_t humMax, float sensorTemp, float externalTemp ) {
float current = float( humCurrent - humMin) / float( humMax - humMin );
/* Compute absolute capacitance from the known references */
float C = calibration.value.refCapLow
+ (calibration.value.refCapHigh - calibration.value.refCapLow) * current;
/* Apply calibration */
float Cp = ( C / calibration.value.calibU[0] - 1.0f) * calibration.value.calibU[1];
Serial.printf("Cp = %f\n", Cp );
int j, k;
float sum = 0;
float xj = 1.0f;
for (j = 0; j < 7; j++) {
float yk = 1.0f;
for (k = 0; k < 6; k++) {
sum += xj * yk * calibration.value.matrixU[j][k];
yk *= ( sensorTemp - 20.0f) / 180.0f;
}
xj *= Cp;
}
/* Since there is always a small difference between the temperature readings for
* the atmospheric (main) tempoerature sensor and the temperature sensor inside
* the humidity sensor device, transform the humidity value to the atmospheric conditions
* with its different water vapor saturation pressure.
*/
float RH = sum
* _RS41_waterVaporSaturationPressure(sensorTemp)
/ _RS41_waterVaporSaturationPressure(externalTemp);
return RH;
}
// returns: 0: ok, -1: rs or crc error
int RS41::decode41(byte *data, int maxlen)
@ -457,6 +701,13 @@ int RS41::decode41(byte *data, int maxlen)
sonde.si()->countKT = cntdown;
sonde.si()->crefKT = fnr;
}
// process this subframe
int subframeOffset = 24; // 24 = 0x18, start of subframe data
byte receivedBytes[16];
memcpy( receivedBytes, data+p+subframeOffset, 16);
ProcessSubframe( receivedBytes, calnr );
}
// TODO: some more data
break;
@ -476,6 +727,64 @@ int RS41::decode41(byte *data, int maxlen)
case '{': // pos
posrs41(data+p, len, 0);
break;
case 'z': // 0x7a is character z - 7A-MEAS temperature and humidity frame
{
uint32_t tempMeasMain = getint24(data, 560, p+0);
uint32_t tempMeasRef1 = getint24(data, 560, p+3);
uint32_t tempMeasRef2 = getint24(data, 560, p+6);
uint32_t humidityMain = getint24(data, 560, p+9);
uint32_t humidityRef1 = getint24(data, 560, p+12);
uint32_t humidityRef2 = getint24(data, 560, p+15);
uint32_t tempHumiMain = getint24(data, 560, p+18);
uint32_t tempHumiRef1 = getint24(data, 560, p+21);
uint32_t tempHumiRef2 = getint24(data, 560, p+24);
uint32_t pressureMain = getint24(data, 560, p+27);
uint32_t pressureRef1 = getint24(data, 560, p+30);
uint32_t pressureRef2 = getint24(data, 560, p+33);
#if 0
Serial.printf( "External temp: tempMeasMain = %ld, tempMeasRef1 = %ld, tempMeasRef2 = %ld\n", tempMeasMain, tempMeasRef1, tempMeasRef2 );
Serial.printf( "Rel Humidity: humidityMain = %ld, humidityRef1 = %ld, humidityRef2 = %ld\n", humidityMain, humidityRef1, humidityRef2 );
Serial.printf( "Humid sensor: tempHumiMain = %ld, tempHumiRef1 = %ld, tempHumiRef2 = %ld\n", tempHumiMain, tempHumiRef1, tempHumiRef2 );
Serial.printf( "Pressure sens: pressureMain = %ld, pressureRef1 = %ld, pressureRef2 = %ld\n", pressureMain, pressureRef1, pressureRef2 );
#endif
// for a valid temperature, require rLow rHigh (frames 3 4) TaylorT (frames 4 5), polyT (frames 5 6 7),
validExternalTemperature = subframeReceived[3] && subframeReceived[4] && subframeReceived[5]
&& subframeReceived[6] && subframeReceived[7];
// for a valid RA humidity, valid temperature, calibU (frame 7) matrixU (frame 7-12), taylorTU (frame 12 13),
// calTU (frame 13) polyTrh (frame 13 14)
validHumidity = validExternalTemperature && subframeReceived[0x08] && subframeReceived[0x09] && subframeReceived[0x0A]
&& subframeReceived[0x0B] && subframeReceived[0x0C] && subframeReceived[0x0D] && subframeReceived[0x0E]
&& subframeReceived[0x0F] && subframeReceived[0x10] && subframeReceived[0x11] && subframeReceived[0x12];
if ( validExternalTemperature ) {
if ( tempMeasMain > tempMeasRef1 && tempMeasMain < tempMeasRef2 ) {
sonde.si()->temperature = GetRATemp( tempMeasMain, tempMeasRef1, tempMeasRef2,
calibration.value.calT, calibration.value.taylorT, calibration.value.polyT );
Serial.printf("tempRA = %f\n", sonde.si()->temperature );
}
else {
Serial.println( "External temperature data measurement mismatch");
}
}
if ( validHumidity ) {
if ( tempHumiMain > tempHumiRef1 && tempHumiMain < tempHumiRef2 ) {
sonde.si()->tempRHSensor = GetRATemp( tempHumiMain, tempHumiRef1, tempHumiRef2,
calibration.value.calTU, calibration.value.taylorTU, calibration.value.polyTrh );
sonde.si()->relativeHumidity = GetRAHumidity( humidityMain, humidityRef1, humidityRef2, sonde.si()->tempRHSensor, sonde.si()->temperature );
Serial.printf("Relative humidity = %f\n", sonde.si()->relativeHumidity );
}
else {
Serial.println( "Sensor temperature data measurement mismatch" );
}
}
}
break;
default:
break;
}}

3
libraries/SondeLib/Sonde.h
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@ -99,6 +99,9 @@ typedef struct st_sondeinfo {
// shut down timers, currently only for RS41; -1=disabled
int16_t launchKT, burstKT, countKT;
uint16_t crefKT; // frame number in which countKT was last sent
float temperature = -300.0; // platinum resistor temperature
float tempRHSensor = -300.0; // temperature of relative humidity sensor
float relativeHumidity = -1.0; // relative humidity
} SondeInfo;
// rxStat: 3=undef[empty] 1=timeout[.] 2=errro[E] 0=ok[|] 4=no valid position[°]