System Call function constants

ColorSensorRead CommBTCheckStatus CommBTConnection CommBTOnOff CommBTRead CommBTWrite CommExecuteFunction CommHSCheckStatus CommHSControl CommHSRead CommHSWrite CommLSCheckStatus CommLSRead CommLSWrite CommLSWriteEx ComputeCalibValue DatalogGetTimes DatalogWrite DisplayExecuteFunction DrawCircle DrawEllipse DrawFont DrawGraphic DrawGraphicArray DrawLine DrawPoint DrawPolygon DrawRect DrawText FileClose FileDelete FileFindFirst FileFindNext FileOpenAppend FileOpenRead FileOpenReadLinear FileOpenWrite FileOpenWriteLinear FileOpenWriteNonLinear FileRead FileRename FileResize FileResolveHandle FileSeek FileTell FileWrite GetStartTick InputPinFunction IOMapRead IOMapReadByID IOMapWrite IOMapWriteByID KeepAlive ListFiles LoaderExecuteFunction MemoryManager MessageRead MessageWrite RandomEx RandomNumber ReadButton ReadLastResponse ReadSemData SetScreenMode SetSleepTimeoutVal SoundGetState SoundPlayFile SoundPlayTone SoundSetState UpdateCalibCacheInfo WriteSemData

#define ReadButton   20 Read the current button state