user13633: I'm new to Arduino and I'm trying to get my MPU 6050  chip to work. The simple code runs fine but when I use the downloaded example I get the following:
Arduino: 1.6.5 (Windows 7), Board: "Arduino/Genuino Uno"
Build options changed, rebuilding all
....

g.cpp.o 

C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-gcc -w -Os -Wl,--gc-sections -mmcu=atmega328p -o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp/MPU6050_DMP6.cpp.elf C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050_DMP6.cpp.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\Wire\Wire.cpp.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\Wire\utility\twi.c.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp/core.a -LC:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp -lm 

C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setRate(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:133: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setExternalFrameSync(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:175: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDLPFMode(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:218: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setFullScaleGyroRange(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:253: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setFullScaleAccelRange(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:387: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMotionDetectionThreshold(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:531: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMotionDetectionDuration(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:561: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZeroMotionDetectionThreshold(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:601: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZeroMotionDetectionDuration(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:632: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setSlaveAddress(unsigned char, unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:972: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o:C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1558: more undefined references to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)' follow
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getIntStatus()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1687: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1687: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1687: undefined reference to `I2Cdev::readByte(unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setFIFOEnabled(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2351: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setI2CMasterModeEnabled(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2375: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::resetFIFO()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2391: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::resetI2CMaster()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2400: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::reset()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2426: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o:C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2450: more undefined references to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)' follow
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setClockSource(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2543: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getFIFOCount()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2708: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2708: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2708: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getFIFOBytes(unsigned char*, unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2744: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2744: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2744: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getDeviceID()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2764: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2764: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2764: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getOTPBankValid()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2785: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2785: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2785: undefined reference to `I2Cdev::readBit(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setOTPBankValid(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2789: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getXGyroOffsetTC()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2792: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2792: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2792: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setXGyroOffsetTC(signed char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2796: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getYGyroOffsetTC()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2802: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2802: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2802: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setYGyroOffsetTC(signed char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2806: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getZGyroOffsetTC()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2812: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2812: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2812: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZGyroOffsetTC(signed char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2816: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZAccelOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2876: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setXGyroOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2886: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setYGyroOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2896: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZGyroOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2906: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDMPEnabled(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2971: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::resetDMP()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2974: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMemoryBank(unsigned char, bool, bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2983: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMemoryStartAddress(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2989: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::readMemoryByte()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2995: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2995: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2995: undefined reference to `I2Cdev::readByte(unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::readMemoryBlock(unsigned char*, unsigned int, unsigned char, unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3016: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3016: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3016: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::writeMemoryBlock(unsigned char const*, unsigned int, unsigned char, unsigned char, bool, bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3060: undefined reference to `I2Cdev::writeBytes(unsigned char, unsigned char, unsigned char, unsigned char*)'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3066: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3066: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3066: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::writeDMPConfigurationSet(unsigned char const*, unsigned int, bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3170: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDMPConfig1(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3198: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDMPConfig2(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3208: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
collect2.exe: error: ld returned 1 exit status
Error compiling.

Help would be most appreciated
Thanks!

user7856: You seem to be missing the I2C header.
If you are using the Arduino IDE, beware that it has its own whacky idea of where headers should be. Try adding the #include to the .ino file.

13633: <p>I'm new to Arduino and I'm trying to get my MPU 6050  chip to work. The simple code runs fine but when I use the downloaded example I get the following:</p>

<p>Arduino: 1.6.5 (Windows 7), Board: "Arduino/Genuino Uno"</p>

<pre><code>Build options changed, rebuilding all
....

g.cpp.o 

C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-gcc -w -Os -Wl,--gc-sections -mmcu=atmega328p -o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp/MPU6050_DMP6.cpp.elf C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050_DMP6.cpp.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\Wire\Wire.cpp.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\Wire\utility\twi.c.o C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp/core.a -LC:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp -lm 

C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setRate(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:133: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setExternalFrameSync(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:175: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDLPFMode(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:218: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setFullScaleGyroRange(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:253: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setFullScaleAccelRange(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:387: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMotionDetectionThreshold(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:531: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMotionDetectionDuration(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:561: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZeroMotionDetectionThreshold(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:601: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZeroMotionDetectionDuration(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:632: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setSlaveAddress(unsigned char, unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:972: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o:C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1558: more undefined references to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)' follow
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getIntStatus()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1687: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1687: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:1687: undefined reference to `I2Cdev::readByte(unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setFIFOEnabled(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2351: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setI2CMasterModeEnabled(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2375: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::resetFIFO()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2391: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::resetI2CMaster()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2400: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::reset()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2426: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o:C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2450: more undefined references to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)' follow
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setClockSource(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2543: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getFIFOCount()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2708: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2708: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2708: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getFIFOBytes(unsigned char*, unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2744: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2744: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2744: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getDeviceID()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2764: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2764: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2764: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getOTPBankValid()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2785: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2785: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2785: undefined reference to `I2Cdev::readBit(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setOTPBankValid(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2789: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getXGyroOffsetTC()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2792: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2792: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2792: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setXGyroOffsetTC(signed char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2796: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getYGyroOffsetTC()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2802: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2802: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2802: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setYGyroOffsetTC(signed char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2806: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::getZGyroOffsetTC()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2812: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2812: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2812: undefined reference to `I2Cdev::readBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZGyroOffsetTC(signed char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2816: undefined reference to `I2Cdev::writeBits(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZAccelOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2876: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setXGyroOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2886: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setYGyroOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2896: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setZGyroOffset(int)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2906: undefined reference to `I2Cdev::writeWord(unsigned char, unsigned char, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDMPEnabled(bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2971: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::resetDMP()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2974: undefined reference to `I2Cdev::writeBit(unsigned char, unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMemoryBank(unsigned char, bool, bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2983: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setMemoryStartAddress(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2989: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::readMemoryByte()':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2995: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2995: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:2995: undefined reference to `I2Cdev::readByte(unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::readMemoryBlock(unsigned char*, unsigned int, unsigned char, unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3016: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3016: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3016: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::writeMemoryBlock(unsigned char const*, unsigned int, unsigned char, unsigned char, bool, bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3060: undefined reference to `I2Cdev::writeBytes(unsigned char, unsigned char, unsigned char, unsigned char*)'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3066: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3066: undefined reference to `I2Cdev::readTimeout'
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3066: undefined reference to `I2Cdev::readBytes(unsigned char, unsigned char, unsigned char, unsigned char*, unsigned int)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::writeDMPConfigurationSet(unsigned char const*, unsigned int, bool)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3170: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDMPConfig1(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3198: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
C:\Users\Emma\AppData\Local\Temp\build2536911660206936106.tmp\MPU6050\MPU6050.cpp.o: In function `MPU6050::setDMPConfig2(unsigned char)':
C:\Users\Emma\Documents\Arduino\libraries\MPU6050/MPU6050.cpp:3208: undefined reference to `I2Cdev::writeByte(unsigned char, unsigned char, unsigned char)'
collect2.exe: error: ld returned 1 exit status
Error compiling.
</code></pre>

<p>Help would be most appreciated</p>

<p>Thanks!</p>
 7856: <p>You seem to be missing the I2C header.
If you are using the Arduino IDE, beware that it has its own whacky idea of where headers should be. Try adding the #include to the .ino file.</p>
