I'm trying to use a 9DOF IMU I purchased from eBay.
Similar to the one here: Introduction | Adafruit 9-DOF IMU Breakout | Adafruit Learning System
I connected the sensor to the arduino as described on their website and tried to use the checking code they posted (added below).
I keep getting an error message that I have to check the wires because the sensor isn't found.
Has anyone here had any experience with connecting IMU's and arduinos? would love some help 
Thank you!
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_LSM303_U.h>
#include <Adafruit_L3GD20_U.h>
#include <Adafruit_9DOF.h>
/* Assign a unique ID to the sensors */
Adafruit_9DOF dof = Adafruit_9DOF();
Adafruit_LSM303_Accel_Unified accel = Adafruit_LSM303_Accel_Unified(30301);
Adafruit_LSM303_Mag_Unified mag = Adafruit_LSM303_Mag_Unified(30302);
/* Update this with the correct SLP for accurate altitude measurements */
float seaLevelPressure = SENSORS_PRESSURE_SEALEVELHPA;
/**************************************************************************/
/*!
@brief Initialises all the sensors used by this example
*/
/**************************************************************************/
void initSensors()
{
if(!accel.begin())
{
/* There was a problem detecting the LSM303 ... check your connections */
Serial.println(F("Ooops, no LSM303 detected ... Check your wiring!"));
while(1);
}
if(!mag.begin())
{
/* There was a problem detecting the LSM303 ... check your connections */
Serial.println("Ooops, no LSM303 detected ... Check your wiring!");
while(1);
}
}
/**************************************************************************/
/*!
*/
/**************************************************************************/
void setup(void)
{
Serial.begin(9600);
Serial.println(F("Adafruit 9 DOF Pitch/Roll/Heading Example")); Serial.println("");
/* Initialise the sensors */
initSensors();
}
/**************************************************************************/
/*!
@brief Constantly check the roll/pitch/heading/altitude/temperature
*/
/**************************************************************************/
void loop(void)
{
sensors_event_t accel_event;
sensors_event_t mag_event;
sensors_vec_t orientation;
/* Calculate pitch and roll from the raw accelerometer data */
accel.getEvent(&accel_event);
if (dof.accelGetOrientation(&accel_event, &orientation))
{
/* 'orientation' should have valid .roll and .pitch fields */
Serial.print(F("Roll: "));
Serial.print(orientation.roll);
Serial.print(F("; "));
Serial.print(F("Pitch: "));
Serial.print(orientation.pitch);
Serial.print(F("; "));
}
/* Calculate the heading using the magnetometer */
mag.getEvent(&mag_event);
if (dof.magGetOrientation(SENSOR_AXIS_Z, &mag_event, &orientation))
{
/* 'orientation' should have valid .heading data now */
Serial.print(F("Heading: "));
Serial.print(orientation.heading);
Serial.print(F("; "));
}
Serial.println(F(""));
delay(0);
}