main.cpp

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#include "main.h"
 
#include <Arduino.h>
#include <Wire.h>
#include <math.h>
 
#include "SparkFun_LPS28DFW_Arduino_Library.h"
 
static LPS28DFW pressureSensor;
 
/** Barometric altitude (m) from static pressure using a simple ISA troposphere
 * fit. */
static float pressureToAltitudeM(float pressureHpa, float seaLevelHpa) {
    if (pressureHpa <= 0.f || seaLevelHpa <= 0.f)
        return NAN;
    // h = 44330 * (1 - (P/P0)^(1/5.255)); exponent ≈ 0.190284
    return 44330.0f * (1.0f - powf(pressureHpa / seaLevelHpa, 0.190284f));
}
 
void setup() {
    Serial.begin(115200);
    while (!Serial)
        delay(10);
 
    Wire.begin(LPS28DFW_SDA_PIN, LPS28DFW_SCL_PIN);
 
    while (pressureSensor.begin(LPS28DFW_I2C_ADDR, Wire) != LPS28DFW_OK) {
        Serial.println(
            "ERROR: LPS28DFW not found. Check wiring and I2C address (0x5C / "
            "0x5D).");
        delay(1000);
    }
 
    lps28dfw_md_t modeConfig = {
        .fs = LPS28DFW_1260hPa,
        .odr = LPS28DFW_10Hz,
        .avg = LPS28DFW_32_AVG,
        .lpf = LPS28DFW_LPF_DISABLE,
    };
    if (pressureSensor.setModeConfig(&modeConfig) != LPS28DFW_OK) {
        Serial.println("ERROR: setModeConfig failed.");
        while (1)
            delay(1000);
    }
 
    Serial.println();
    Serial.println("LPS28DFW test (SparkFun library)");
    Serial.printf(
        "Altitude uses ISA P0 = %.2f hPa (change LPS28DFW_SEA_LEVEL_HPA to "
        "match local pressure)\r\n",
        LPS28DFW_SEA_LEVEL_HPA);
    Serial.println();
}
 
void loop() {
    if (pressureSensor.getSensorData() != LPS28DFW_OK) {
        Serial.println("ERROR: getSensorData failed");
        delay(500);
        return;
    }
 
    const float tempC = pressureSensor.data.heat.deg_c;
    const float pressHpa = pressureSensor.data.pressure.hpa;
    const float altM = pressureToAltitudeM(pressHpa, LPS28DFW_SEA_LEVEL_HPA);
 
    Serial.printf("Temperature: %.3f C\r\n", tempC);
    Serial.printf("Pressure:    %.3f hPa\r\n", pressHpa);
    Serial.printf("Altitude:    %.1f m (barometric, ISA)\r\n", altM);
    Serial.println();
 
    delay(1000);
}