Arduino APIs added by firmware version

Language - Arduino Compatibility

Once Arduino.h has been added to a source file, additional Arduino APIs are made available. The APIs added are determined by the targeted firmware version. In addition to defining the new APIs, the ARDUINO symbol is set to a value that describes the supported SDK version. (e.g. 10800 for 1.8.0)

The table below lists the Arduino APIs added for each firmware version and the value of the ARDUINO symbol.

API name	description	ARDUINO version	Particle version
SPISettings		10800	0.6.2
__FastStringHelper		10800	0.6.2
Wire.setClock	synonym for `Wire.setSpeed`	10800	0.6.2
SPI.usingInterrupt	NB: this function is included to allow libraries to compile, but is implemented as a empty function.	10800	0.6.2
LED_BUILTIN	defines the pin that corresponds to the built-in LED	10800	0.6.2