Problem with SPI BMP280 & H3LIS331DL

Hi!

I have been trying to use a BMP280 and an H3LIS331DL with an Arduino Uno via SPI for a couple of days and when I use one at a time, they work flawlessly. However, when I try to use both at the same time, an error shows up in the Serial Monitor.

Instead of the altitude, it writes “nan”. I don’t understand why. I use exactly the same code for the BMP280 when I use it with and without the other sensor.

#include <SparkFun_LIS331.h>
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_BMP280.h>

#define BMP_SCK  (13)
#define BMP_MISO (12)
#define BMP_MOSI (11)
#define BMP_CS   (9)

Adafruit_BMP280 bmp(BMP_CS, BMP_MOSI, BMP_MISO,  BMP_SCK);

LIS331 xl;


void setup() {
  Serial.begin(9600);
  Serial.println(F("BMP280 test"));

  if (!bmp.begin()) {
    Serial.println(F("Could not find a valid BMP280 sensor, check wiring!"));
    while (1);
  }

  /* Default settings from datasheet. */
  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); /* Standby time. */

  pinMode(8,INPUT);       // Interrupt pin input
  pinMode(10, OUTPUT);    // CS for SPI
  digitalWrite(10, HIGH); // Make CS high
  pinMode(11, OUTPUT);    // MOSI for SPI
  pinMode(12, INPUT);     // MISO for SPI
  pinMode(13, OUTPUT);    // SCK for SPI
  SPI.begin();
  xl.setSPICSPin(10);     // This MUST be called BEFORE .begin() so 
                          //  .begin() can communicate with the chip
  xl.begin(LIS331::USE_SPI); // Selects the bus to be used and sets
                          //  the power up bit on the accelerometer.
                          //  Also zeroes out all accelerometer
                          //  registers that are user writable.
  // This next section configures an interrupt. It will cause pin
  //  INT1 on the accelerometer to go high when the absolute value
  //  of the reading on the Z-axis exceeds a certain level for a
  //  certain number of samples.
  xl.intSrcConfig(LIS331::INT_SRC, 1); // Select the source of the
                          //  signal which appears on pin INT1. In
                          //  this case, we want the corresponding
                          //  interrupt's status to appear. 
  xl.setIntDuration(50, 1); // Number of samples a value must meet
                          //  the interrupt condition before an
                          //  interrupt signal is issued. At the
                          //  default rate of 50Hz, this is one sec.
  xl.setIntThreshold(2, 1); // Threshold for an interrupt. This is
                          //  not actual counts, but rather, actual
                          //  counts divided by 16.
  xl.enableInterrupt(LIS331::Z_AXIS, LIS331::TRIG_ON_HIGH, 1, true);
                          // Enable the interrupt. Parameters indicate
                          //  which axis to sample, when to trigger
                          //  (in this case, when the absolute mag
                          //  of the signal exceeds the threshold),
                          //  which interrupt source we're configuring,
                          //  and whether to enable (true) or disable
                          //  (false) the interrupt.
}

void loop() {
  
    Serial.print(F("Temperature = "));
    Serial.print(bmp.readTemperature());
    Serial.println(" *C");

    Serial.print(F("Pressure = "));
    Serial.print(bmp.readPressure());
    Serial.println(" Pa");

    Serial.print(F("Approx altitude = "));
    Serial.print(bmp.readAltitude(1013.25)); /* Adjusted to local forecast! */
    Serial.println(" m");

  static long loopTimer = 0;
  int16_t x, y, z;
  if (millis() - loopTimer > 1000)
  {
    loopTimer = millis();
    xl.readAxes(x, y, z);  // The readAxes() function transfers the
                           //  current axis readings into the three
                           //  parameter variables passed to it.
    Serial.println(x);
    Serial.println(y);
    Serial.println(z);
    Serial.println(xl.convertToG(6,x)); // The convertToG() function
    Serial.println(xl.convertToG(6,y)); // accepts as parameters the
    Serial.println(xl.convertToG(6,z)); // raw value and the current
    Serial.println(" ");                // maximum g-rating.
  }
    Serial.println();
    delay(500);
}

I am using the official code from:

https://learn.sparkfun.com/tutorials/h3lis331dl-accelerometer-breakout-hookup-guide?_ga=2.78861268.1377347010.1560794051-2070279539.1551687244

for the H3LIS331DL and the example from the Adafruit_BMP280 library.

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No problem.PNG

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Bob.