ds3231: basic support for DS3231 RTC device

ds3231/registers.go

@@ -0,0 +1,48 @@
+package ds3231
+
+// The I2C address which this device listens to.
+const Address = 0x68
+
+// Registers
+const (
+	REG_TIMEDATE = 0x00
+	REG_ALARMONE = 0x07
+	REG_ALARMTWO = 0x0B
+
+	REG_CONTROL = 0x0E
+	REG_STATUS  = 0x0F
+	REG_AGING   = 0x10
+
+	REG_TEMP = 0x11
+
+	REG_ALARMONE_SIZE = 4
+	REG_ALARMTWO_SIZE = 3
+
+	// DS3231 Control Register Bits
+	A1IE  = 0
+	A2IE  = 1
+	INTCN = 2
+	RS1   = 3
+	RS2   = 4
+	CONV  = 5
+	BBSQW = 6
+	EOSC  = 7
+
+	// DS3231 Status Register Bits
+	A1F     = 0
+	A2F     = 1
+	BSY     = 2
+	EN32KHZ = 3
+	OSF     = 7
+
+	AlarmFlag_Alarm1    = 0x01
+	AlarmFlag_Alarm2    = 0x02
+	AlarmFlag_AlarmBoth = 0x03
+
+	None          Mode = 0
+	BatteryBackup Mode = 1
+	Clock         Mode = 2
+	AlarmOne      Mode = 3
+	AlarmTwo      Mode = 4
+	ModeAlarmBoth Mode = 5
+)