user31311: I am currently working with two Arduinos and I'm trying to synchronize them. I want to get data from four LIS3DH accelerometers. The LIS3DH accelerometers are connected to the Arduino using I2C interface. I have managed to get the Arduinos to synchronize using SPI but when I get the third set of data it keeps on showing OVF rather than the values. My code is below can someone please help me out? 
Thanks 
// SPI Master
#include <Wire.h>
#include <SPI.h>
#include "SPI_anything.h"
#include <Adafruit_LIS3DH.h>
#include <Adafruit_Sensor.h>

//#define LIS3DH_CLK 13
//#define LIS3DH_MISO 12
//#define LIS3DH_MOSI 11
//#define LIS3DH_CS  10

// I2C
Adafruit_LIS3DH lisch1 = Adafruit_LIS3DH();
Adafruit_LIS3DH lisch2 = Adafruit_LIS3DH();
// Adafruit_LIS3DH lisch3 = Adafruit_LIS3DH();
struct event3;

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using
// programming port to program the Zero!
#define Serial SerialUSB
#endif

void setup() {
#ifndef ESP8266
  while (!Serial)
    ; // will pause Zero, Leonardo, etc until serial console opens
#endif

  Serial.begin(9600);

  // have to send on master in, *slave out*
  pinMode(MISO, OUTPUT);

  // turn on SPI in slave mode
  SPCR |= _BV(SPE);

  Serial.println("LIS3DH test!");

  if (!lisch1.begin(0x19)) { // change this to 0x19 for alternative i2c address
                             // - Voltage SDO

    Serial.println("Couldnt start");
    while (1)
      ;
  }
  Serial.println("LIS3DH1 found!");
  if (!lisch2.begin(0x18)) { // change this to 0x18 for alternative i2c address
                             // - Ground SDO
    Serial.println("Couldnt start");
    while (1)
      ;
  }
  Serial.println("LIS3DH2 found!");

  lisch1.setRange(LIS3DH_RANGE_16_G); // 2, 4, 8 or 16 G!
  lisch2.setRange(LIS3DH_RANGE_16_G); // 2, 4, 8 or 16 G!

  Serial.print("Range = ");
  Serial.print(2 << lisch1.getRange());
  Serial.print("Range = ");
  Serial.print(2 << lisch2.getRange());
  Serial.println("G");
}

void loop() {

  lisch1.read(); // get X Y and Z data at once

  /* Or....get a new sensor event, normalized */
  sensors_event_t event;

  lisch1.getEvent(&event);

  /* Display the results (acceleration is measured in m/s^2) */
  Serial.print(" \t ");
  Serial.print(event.acceleration.x);
  Serial.print(" \t ");
  Serial.print(event.acceleration.y);
  Serial.print(" \t ");
  Serial.print(event.acceleration.z);

  lisch2.read(); // get X Y and Z data at once
  lisch2.getEvent(&event);

  /* Display the results (acceleration is measured in m/s^2) */
  Serial.print(" \t ");
  Serial.print(event.acceleration.x);
  Serial.print(" \t ");
  Serial.print(event.acceleration.y);
  Serial.print(" \t ");
  Serial.print(event.acceleration.z);

  struct event;

  SPI_readAnything(event);
  //  sensors_event_t event;

  //  lisch3.getEvent(&event);
  Serial.print(" \t "); Serial.print(float2s(event.acceleration.x,6);
  Serial.print(" \t "); Serial.print(event.acceleration.y); 
  Serial.print(" \t "); Serial.print(event.acceleration.z);
  Serial.println ();


  delay(500);
}

/ SPI Slave

#include <Wire.h>
#include <SPI.h>
#include "SPI_anything.h"
#include <Adafruit_LIS3DH.h>
#include <Adafruit_Sensor.h>

#define LIS3DH_CLK 13
#define LIS3DH_MISO 12
#define LIS3DH_MOSI 11
#define LIS3DH_CS 10

    // I2C
    Adafruit_LIS3DH lisch3 = Adafruit_LIS3DH();

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using
// programming port to program the Zero!
#define Serial SerialUSB
#endif

void setup() {
#ifndef ESP8266
  while (!Serial)
    ; // will pause Zero, Leonardo, etc until serial console opens
#endif

  Serial.begin(9600); // start serial for output

  SPI.begin();

  // Slow down the master a bit
  SPI.setClockDivider(SPI_CLOCK_DIV8);

  Serial.println("LIS3DH3 test!");

  if (!lisch3.begin(0x19)) { // change this to 0x19 for alternative i2c address
                             // - Voltage SDO

    Serial.println("Couldnt start");
    while (1)
      ;
  }
  Serial.println("LIS3DH3 found!");

  lisch3.setRange(LIS3DH_RANGE_16_G); // 2, 4, 8 or 16 G!

  Serial.print("Range = ");
  Serial.print(2 << lisch3.getRange());

  Serial.println("G");
}

void loop() {

  lisch3.read(); // get X Y and Z data at once

  /* Or....get a new sensor event, normalized */
  sensors_event_t event;

  lisch3.getEvent(&event);

  /* Display the results (acceleration is measured in m/s^2) */
  Serial.print(" \t ");
  Serial.print(event.acceleration.x);
  Serial.print(" \t ");
  Serial.print(event.acceleration.y);
  Serial.print(" \t ");
  Serial.print(event.acceleration.z);
  Serial.println();

  digitalWrite(SS, LOW); // SS is pin 10
  SPI_writeAnything(event);
  digitalWrite(SS, HIGH);
  //  delay (1000);  // for testing

  delay(100);
}


user42384: OVF means overflow, you probably exceeded the range of the data type you're using. Try /1000; /10000000000 etc to your variable until you don't get the OVF or use a datatype with a bigger range.  

31311: <p>I am currently working with two Arduinos and I'm trying to synchronize them. I want to get data from four LIS3DH accelerometers. The LIS3DH accelerometers are connected to the Arduino using I2C interface. I have managed to get the Arduinos to synchronize using SPI but when I get the third set of data it keeps on showing OVF rather than the values. My code is below can someone please help me out? </p>

<p>Thanks </p>

<pre><code>// SPI Master
#include &lt;Wire.h&gt;
#include &lt;SPI.h&gt;
#include "SPI_anything.h"
#include &lt;Adafruit_LIS3DH.h&gt;
#include &lt;Adafruit_Sensor.h&gt;

//#define LIS3DH_CLK 13
//#define LIS3DH_MISO 12
//#define LIS3DH_MOSI 11
//#define LIS3DH_CS  10

// I2C
Adafruit_LIS3DH lisch1 = Adafruit_LIS3DH();
Adafruit_LIS3DH lisch2 = Adafruit_LIS3DH();
// Adafruit_LIS3DH lisch3 = Adafruit_LIS3DH();
struct event3;

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using
// programming port to program the Zero!
#define Serial SerialUSB
#endif

void setup() {
#ifndef ESP8266
  while (!Serial)
    ; // will pause Zero, Leonardo, etc until serial console opens
#endif

  Serial.begin(9600);

  // have to send on master in, *slave out*
  pinMode(MISO, OUTPUT);

  // turn on SPI in slave mode
  SPCR |= _BV(SPE);

  Serial.println("LIS3DH test!");

  if (!lisch1.begin(0x19)) { // change this to 0x19 for alternative i2c address
                             // - Voltage SDO

    Serial.println("Couldnt start");
    while (1)
      ;
  }
  Serial.println("LIS3DH1 found!");
  if (!lisch2.begin(0x18)) { // change this to 0x18 for alternative i2c address
                             // - Ground SDO
    Serial.println("Couldnt start");
    while (1)
      ;
  }
  Serial.println("LIS3DH2 found!");

  lisch1.setRange(LIS3DH_RANGE_16_G); // 2, 4, 8 or 16 G!
  lisch2.setRange(LIS3DH_RANGE_16_G); // 2, 4, 8 or 16 G!

  Serial.print("Range = ");
  Serial.print(2 &lt;&lt; lisch1.getRange());
  Serial.print("Range = ");
  Serial.print(2 &lt;&lt; lisch2.getRange());
  Serial.println("G");
}

void loop() {

  lisch1.read(); // get X Y and Z data at once

  /* Or....get a new sensor event, normalized */
  sensors_event_t event;

  lisch1.getEvent(&amp;event);

  /* Display the results (acceleration is measured in m/s^2) */
  Serial.print(" \t ");
  Serial.print(event.acceleration.x);
  Serial.print(" \t ");
  Serial.print(event.acceleration.y);
  Serial.print(" \t ");
  Serial.print(event.acceleration.z);

  lisch2.read(); // get X Y and Z data at once
  lisch2.getEvent(&amp;event);

  /* Display the results (acceleration is measured in m/s^2) */
  Serial.print(" \t ");
  Serial.print(event.acceleration.x);
  Serial.print(" \t ");
  Serial.print(event.acceleration.y);
  Serial.print(" \t ");
  Serial.print(event.acceleration.z);

  struct event;

  SPI_readAnything(event);
  //  sensors_event_t event;

  //  lisch3.getEvent(&amp;event);
  Serial.print(" \t "); Serial.print(float2s(event.acceleration.x,6);
  Serial.print(" \t "); Serial.print(event.acceleration.y); 
  Serial.print(" \t "); Serial.print(event.acceleration.z);
  Serial.println ();


  delay(500);
}

/ SPI Slave

#include &lt;Wire.h&gt;
#include &lt;SPI.h&gt;
#include "SPI_anything.h"
#include &lt;Adafruit_LIS3DH.h&gt;
#include &lt;Adafruit_Sensor.h&gt;

#define LIS3DH_CLK 13
#define LIS3DH_MISO 12
#define LIS3DH_MOSI 11
#define LIS3DH_CS 10

    // I2C
    Adafruit_LIS3DH lisch3 = Adafruit_LIS3DH();

#if defined(ARDUINO_ARCH_SAMD)
// for Zero, output on USB Serial console, remove line below if using
// programming port to program the Zero!
#define Serial SerialUSB
#endif

void setup() {
#ifndef ESP8266
  while (!Serial)
    ; // will pause Zero, Leonardo, etc until serial console opens
#endif

  Serial.begin(9600); // start serial for output

  SPI.begin();

  // Slow down the master a bit
  SPI.setClockDivider(SPI_CLOCK_DIV8);

  Serial.println("LIS3DH3 test!");

  if (!lisch3.begin(0x19)) { // change this to 0x19 for alternative i2c address
                             // - Voltage SDO

    Serial.println("Couldnt start");
    while (1)
      ;
  }
  Serial.println("LIS3DH3 found!");

  lisch3.setRange(LIS3DH_RANGE_16_G); // 2, 4, 8 or 16 G!

  Serial.print("Range = ");
  Serial.print(2 &lt;&lt; lisch3.getRange());

  Serial.println("G");
}

void loop() {

  lisch3.read(); // get X Y and Z data at once

  /* Or....get a new sensor event, normalized */
  sensors_event_t event;

  lisch3.getEvent(&amp;event);

  /* Display the results (acceleration is measured in m/s^2) */
  Serial.print(" \t ");
  Serial.print(event.acceleration.x);
  Serial.print(" \t ");
  Serial.print(event.acceleration.y);
  Serial.print(" \t ");
  Serial.print(event.acceleration.z);
  Serial.println();

  digitalWrite(SS, LOW); // SS is pin 10
  SPI_writeAnything(event);
  digitalWrite(SS, HIGH);
  //  delay (1000);  // for testing

  delay(100);
}
</code></pre>
 42384: <p>OVF means overflow, you probably exceeded the range of the data type you're using. Try /1000; /10000000000 etc to your variable until you don't get the OVF or use a datatype with a bigger range.  </p>
