GPIO Adventures on Raspberry Pi #wiringPi

23 December 2014

Linking Error

/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../libwiringPi.so: undefined reference to `i2c_smbus_write_byte'
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../libwiringPi.so: undefined reference to `i2c_smbus_read_byte'
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../libwiringPi.so: undefined reference to `i2c_smbus_write_byte_data'
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../libwiringPi.so: undefined reference to `i2c_smbus_write_word_data'
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../libwiringPi.so: undefined reference to `i2c_smbus_read_word_data'
/usr/lib/gcc/arm-linux-gnueabihf/4.6/../../../libwiringPi.so: undefined reference to `i2c_smbus_read_byte_data'
collect2: ld returned 1 exit status

Dependencies

After googling, the reasons are locked: libi2c-dev, i2c-tools and python-smbus and can be installed as following:

sudo apt-get install libi2c-dev python-smbus

As can be seen i2c-tools is resolved and installed automatically.

Rebuild

Rebuild is necessary, meaning uninstalling and cleaning before making and installing again.

`gpio`

This time the gpio utility is usable.

gpio -V

gpio readall