Supports I2C and SPI via the Wire and SPI libraries, respectively
Supports I2C and SPI interfaces via other libraries (e.g. Software I2C) by inheritance
Automatic antenna tuning

Changelog:

1.3.3 fixed https://bitbucket.org/christandlg/as3935mi/issues/49/class-spiclass-has-no-member-named
1.3.2 fixed https://bitbucket.org/christandlg/as3935mi/issues/47/need-help-using-as3935spiclass
1.3.1 fixed https://bitbucket.org/christandlg/as3935mi/issues/48/clear-statistics-function-to-be-added
1.3.0 fixed https://bitbucket.org/christandlg/as3935mi/issues/12/autocalibrate-no-longer-working
1.2.1 Merged PR by Hernán Freschi https://bitbucket.org/christandlg/as3935mi/pull-requests/2
1.2.0
- extended examples to include increasing sensitivity if no disturbances are detected.
1.1.1
- fixed an issue where ESP8266 would crash with message "ISR not in IRAM"
1.1.0
- extended function calibrateResonanceFrequency() to return the resonance frequency of the antenna
1.0.0
- added more values for watchdog threshold and spike rejection ratio settings
- fixed an incorrect function name
- added missing function names to keywords.txt
0.5.0
- added new classes AS3935TwoWire and AS3935SPIClass for TwoWire and SPIClass interfaces
- moved AS3935I2C and AS3935SPI classes into their own respecitve source files, further separating data processing from communications
- when updating from an earlier version and using the AS3935I2C or AS3935SPI classes, change #include <AS3935MI.h> to #include <AS3935I2C.h> or #include <AS3935SPI.h>, respectively
- added examples for AS3935TwoWire and AS3935SPIClass
0.4.1
- fixed an issue where checkIRQ() causes a deadlock on Arduino Nano
0.4.0
- added functions to increase / decrease noise floor threshold
- added functions to increase / decrease watchdog threshold
- added functions to increase / decrease spike rejection ratio
- added function to check communication to sensor
- added function to check IRQ pin assignment
0.3.0
- derived classes must now implement function beginInterface() instead of begin()
0.2.0
- split code into 3 classes - AS3935MI, AS3935I2C, AS3935SPI
- users can now implement classes derived from AS3935MI easily
- writeRegister is nur used to send direct commands
- updated examples
- added arduino due I2C issue workaround
- minor fixes
- derived
0.1.2
- renamed library
0.1.1
- added license information
0.1.0
- initial release