Add ens160 i2c driver

Driver for ENS160 sensor:
https://www.sciosense.com/wp-content/uploads/2023/12/ENS160-Datasheet.pdf

ens160/registers.go

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+package ens160
+
+// DefaultAddress is the default I2C address for the ENS160 when the ADDR pin is
+// connected to high (3.3V). When connected to low (GND), the address is 0x52.
+const DefaultAddress = 0x53
+
+// Registers
+const (
+	regPartID   = 0x00
+	regOpMode   = 0x10
+	regConfig   = 0x11
+	regCommand  = 0x12
+	regTempIn   = 0x13
+	regRhIn     = 0x15
+	regStatus   = 0x20
+	regAQI      = 0x21
+	regTVOC     = 0x22
+	regECO2     = 0x24
+	regDataT    = 0x30
+	regDataRH   = 0x32
+	regMISR     = 0x38
+	regGPRWrite = 0x40
+	regGPRRead  = 0x48
+)
+
+// Operating modes
+const (
+	ModeDeepSleep = 0x00
+	ModeIdle      = 0x01
+	ModeStandard  = 0x02
+	ModeReset     = 0xF0
+)
+
+// Status register bits
+const (
+	statusSTATAS = 1 << 7
+	statusSTATER = 1 << 6
+
+	statusValidityMask  = 0x0C
+	statusValidityShift = 2
+
+	statusNEWDAT = 1 << 1
+	statusNEWGPR = 1 << 0
+)
+
+// Validity flags
+const (
+	ValidityNormalOperation     = 0x00
+	ValidityWarmUpPhase         = 0x01 // need ~3 minutes until valid data
+	ValidityInitialStartUpPhase = 0x02 // need ~1 hour until valid data
+	ValidityInvalidOutput       = 0x03
+)
+
+// Commands
+const (
+	cmdNOP       = 0x00
+	cmdGetAppVer = 0x0E
+	cmdClrGPR    = 0xCC
+)
+
+// Part IDs
+const (
+	LowPartID  = 0x60
+	HighPartID = 0x01
+)