diff --git a/devices/bmxx80/bmp180.go b/devices/bmxx80/bmp180.go
index fcdd8e9..814fb61 100644
--- a/devices/bmxx80/bmp180.go
+++ b/devices/bmxx80/bmp180.go
@@ -8,13 +8,13 @@ import (
 	"encoding/binary"
 	"time"
 
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 )
 
 // sense180 reads the device's registers for bmp180.
 //
 // It must be called with d.mu lock held.
-func (d *Dev) sense180(env *devices.Environment) error {
+func (d *Dev) sense180(e *physic.Env) error {
 	// Request temperature conversion and read measurement.
 	if err := d.writeCommands([]byte{0xF4, 0x20 | 0x0E}); err != nil {
 		return d.wrap(err)
@@ -38,8 +38,9 @@ func (d *Dev) sense180(env *devices.Environment) error {
 	}
 	up := (int32(pressureBuf[0])<<16 + int32(pressureBuf[1])<<8 | int32(pressureBuf[2])) >> (8 - d.os)
 	pressure := d.cal180.compensatePressure(up, int32(rawTemp), uint(d.os))
-	env.Temperature = devices.Celsius(temp * 100)
-	env.Pressure = devices.KPascal(pressure)
+	// Convert DeciCelsius to Kelvin.
+	e.Temperature = physic.Temperature(temp)*100*physic.MilliCelsius + physic.ZeroCelsius
+	e.Pressure = physic.Pressure(pressure) * physic.Pascal
 	return nil
 }
 
diff --git a/devices/bmxx80/bmp180_test.go b/devices/bmxx80/bmp180_test.go
index c56ce48..9b86b95 100644
--- a/devices/bmxx80/bmp180_test.go
+++ b/devices/bmxx80/bmp180_test.go
@@ -9,7 +9,7 @@ import (
 	"time"
 
 	"periph.io/x/periph/conn/i2c/i2ctest"
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 )
 
 var opts180 = &Opts{Temperature: O1x, Pressure: O1x}
@@ -74,13 +74,13 @@ func TestSense180_success(t *testing.T) {
 	values := []struct {
 		o Oversampling
 		c byte
-		p devices.KPascal
+		p physic.Pressure
 	}{
-		{Oversampling(42), 0x34, 100567},
-		{O1x, 0x34, 100567},
-		{O2x, 0x74, 100567},
-		{O4x, 0xB4, 100568},
-		{O8x, 0xF4, 100568},
+		{Oversampling(42), 0x34, 100567 * physic.Pascal},
+		{O1x, 0x34, 100567 * physic.Pascal},
+		{O2x, 0x74, 100567 * physic.Pascal},
+		{O4x, 0xB4, 100568 * physic.Pascal},
+		{O8x, 0xF4, 100568 * physic.Pascal},
 	}
 	for _, line := range values {
 		bus := i2ctest.Playback{
@@ -110,18 +110,18 @@ func TestSense180_success(t *testing.T) {
 		if s := dev.String(); s != "BMP180{playback(119)}" {
 			t.Fatal(s)
 		}
-		env := devices.Environment{}
-		if err := dev.Sense(&env); err != nil {
+		e := physic.Env{}
+		if err := dev.Sense(&e); err != nil {
 			t.Fatal(err)
 		}
-		if env.Temperature != 25300 {
-			t.Fatalf("temp %d", env.Temperature)
+		if e.Temperature != 25300*physic.MilliCelsius+physic.ZeroCelsius {
+			t.Fatalf("temp %d", e.Temperature)
 		}
-		if env.Pressure != line.p {
-			t.Fatalf("pressure %d", env.Pressure)
+		if e.Pressure != line.p {
+			t.Fatalf("pressure %d", e.Pressure)
 		}
-		if env.Humidity != 0 {
-			t.Fatalf("humidity %d", env.Humidity)
+		if e.Humidity != 0 {
+			t.Fatalf("humidity %d", e.Humidity)
 		}
 		if err := dev.Halt(); err != nil {
 			t.Fatal(err)
@@ -151,8 +151,8 @@ func TestSense180_fail_1(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	env := devices.Environment{}
-	if dev.Sense(&env) == nil {
+	e := physic.Env{}
+	if dev.Sense(&e) == nil {
 		t.Fatal("sensing should have failed")
 	}
 	if err := bus.Close(); err != nil {
@@ -181,8 +181,8 @@ func TestSense180_fail_2(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	env := devices.Environment{}
-	if dev.Sense(&env) == nil {
+	e := physic.Env{}
+	if dev.Sense(&e) == nil {
 		t.Fatal("sensing should have failed")
 	}
 	if err := bus.Close(); err != nil {
@@ -213,8 +213,8 @@ func TestSense180_fail_3(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	env := devices.Environment{}
-	if dev.Sense(&env) == nil {
+	e := physic.Env{}
+	if dev.Sense(&e) == nil {
 		t.Fatal("sensing should have failed")
 	}
 	if err := bus.Close(); err != nil {
@@ -247,8 +247,8 @@ func TestSense180_fail_4(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	env := devices.Environment{}
-	if dev.Sense(&env) == nil {
+	e := physic.Env{}
+	if dev.Sense(&e) == nil {
 		t.Fatal("sensing should have failed")
 	}
 	if err := bus.Close(); err != nil {
@@ -294,18 +294,18 @@ func TestSenseContinuous180_success(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	env := <-c
-	if env.Temperature != 25300 {
-		t.Fatalf("temp %d", env.Temperature)
+	e := <-c
+	if e.Temperature != 25300*physic.MilliCelsius+physic.ZeroCelsius {
+		t.Fatalf("temp %d", e.Temperature)
 	}
-	if env.Pressure != 100567 {
-		t.Fatalf("pressure %d", env.Pressure)
+	if e.Pressure != 100567*physic.Pascal {
+		t.Fatalf("pressure %d", e.Pressure)
 	}
-	if env.Humidity != 0 {
-		t.Fatalf("humidity %d", env.Humidity)
+	if e.Humidity != 0 {
+		t.Fatalf("humidity %d", e.Humidity)
 	}
 
-	if dev.Sense(&env) == nil {
+	if dev.Sense(&e) == nil {
 		t.Fatal("Sense() should have failed")
 	}
 
@@ -314,7 +314,7 @@ func TestSenseContinuous180_success(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	env = <-c2
+	e = <-c2
 
 	if _, ok := <-c; ok {
 		t.Fatal("c should be closed")
diff --git a/devices/bmxx80/bmx280.go b/devices/bmxx80/bmx280.go
index eca708a..133e84a 100644
--- a/devices/bmxx80/bmx280.go
+++ b/devices/bmxx80/bmx280.go
@@ -7,13 +7,13 @@ package bmxx80
 import (
 	"time"
 
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 )
 
 // sense280 reads the device's registers for bme280/bmp280.
 //
 // It must be called with d.mu lock held.
-func (d *Dev) sense280(env *devices.Environment) error {
+func (d *Dev) sense280(e *physic.Env) error {
 	// All registers must be read in a single pass, as noted at page 21, section
 	// 4.1.
 	// Pressure: 0xF7~0xF9
@@ -32,18 +32,21 @@ func (d *Dev) sense280(env *devices.Environment) error {
 	tRaw := int32(buf[3])<<12 | int32(buf[4])<<4 | int32(buf[5])>>4
 
 	t, tFine := d.cal280.compensateTempInt(tRaw)
-	env.Temperature = devices.Celsius(t * 10)
+	// Convert CentiCelsius to Kelvin.
+	e.Temperature = physic.Temperature(t)*10*physic.MilliCelsius + physic.ZeroCelsius
 
 	if d.opts.Pressure != Off {
 		p := d.cal280.compensatePressureInt64(pRaw, tFine)
-		env.Pressure = devices.KPascal((int32(p) + 127) / 256)
+		// It has 8 bits of fractional Pascal.
+		e.Pressure = physic.Pressure(p) * 15625 * physic.MicroPascal / 4
 	}
 
 	if d.opts.Humidity != Off {
 		// This value is 16 bits as per doc.
 		hRaw := int32(buf[6])<<8 | int32(buf[7])
-		h := d.cal280.compensateHumidityInt(hRaw, tFine)
-		env.Humidity = devices.RelativeHumidity((int32(h)*100 + 511) / 1024)
+		h := physic.RelativeHumidity(d.cal280.compensateHumidityInt(hRaw, tFine))
+		// Convert base 1024 to base 1000.
+		e.Humidity = h * physic.MicroRH * 1000 / 1024
 	}
 	return nil
 }
diff --git a/devices/bmxx80/bmx280_test.go b/devices/bmxx80/bmx280_test.go
index b0afc98..0fa5203 100644
--- a/devices/bmxx80/bmx280_test.go
+++ b/devices/bmxx80/bmx280_test.go
@@ -17,7 +17,6 @@ import (
 	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/conn/spi"
 	"periph.io/x/periph/conn/spi/spitest"
-	"periph.io/x/periph/devices"
 )
 
 // Real data extracted from a device.
@@ -87,21 +86,21 @@ func TestSPISenseBME280_success(t *testing.T) {
 	if s := dev.String(); s != "BME280{playback}" {
 		t.Fatal(s)
 	}
-	env := devices.Environment{}
-	if err := dev.Sense(&env); err != nil {
+	e := physic.Env{}
+	if err := dev.Sense(&e); err != nil {
 		t.Fatal(err)
 	}
 	// TODO(maruel): The values do not make sense but I think I burned my SPI
 	// BME280 by misconnecting it in reverse for a few minutes. It still "work"
 	// but fail to read data. It could also be a bug in the driver. :(
-	if env.Temperature != 62680 {
-		t.Fatalf("temp %d", env.Temperature)
+	if e.Temperature != 62680*physic.MilliCelsius+physic.ZeroCelsius {
+		t.Fatalf("temp %d", e.Temperature)
 	}
-	if env.Pressure != 99576 {
-		t.Fatalf("pressure %d", env.Pressure)
+	if e.Pressure != 99575933593750*physic.NanoPascal {
+		t.Fatalf("pressure %d", e.Pressure)
 	}
-	if env.Humidity != 995 {
-		t.Fatalf("humidity %d", env.Humidity)
+	if e.Humidity != 9950*physic.MicroRH {
+		t.Fatalf("humidity %d", e.Humidity)
 	}
 	if err := s.Close(); err != nil {
 		t.Fatal(err)
@@ -288,7 +287,7 @@ func TestI2CSenseBME280_fail(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if dev.Sense(&devices.Environment{}) == nil {
+	if dev.Sense(&physic.Env{}) == nil {
 		t.Fatal("sense fail read")
 	}
 	// The I/O didn't occur.
@@ -328,18 +327,18 @@ func TestI2CSenseBMP280_success(t *testing.T) {
 	if s := dev.String(); s != "BMP280{playback(118)}" {
 		t.Fatal(s)
 	}
-	env := devices.Environment{}
-	if err := dev.Sense(&env); err != nil {
+	e := physic.Env{}
+	if err := dev.Sense(&e); err != nil {
 		t.Fatal(err)
 	}
-	if env.Temperature != 23720 {
-		t.Fatalf("temp %d", env.Temperature)
+	if e.Temperature != 23720*physic.MilliCelsius+physic.ZeroCelsius {
+		t.Fatalf("temp %d", e.Temperature)
 	}
-	if env.Pressure != 100943 {
-		t.Fatalf("pressure %d", env.Pressure)
+	if e.Pressure != 100942695312500*physic.NanoPascal {
+		t.Fatalf("pressure %d", e.Pressure)
 	}
-	if env.Humidity != 0 {
-		t.Fatalf("humidity %d", env.Humidity)
+	if e.Humidity != 0 {
+		t.Fatalf("humidity %d", e.Humidity)
 	}
 	if err := dev.Halt(); err != nil {
 		t.Fatal(err)
@@ -381,18 +380,18 @@ func TestI2CSenseBME280_success(t *testing.T) {
 	if s := dev.String(); s != "BME280{playback(118)}" {
 		t.Fatal(s)
 	}
-	env := devices.Environment{}
-	if err := dev.Sense(&env); err != nil {
+	e := physic.Env{}
+	if err := dev.Sense(&e); err != nil {
 		t.Fatal(err)
 	}
-	if env.Temperature != 23720 {
-		t.Fatalf("temp %d", env.Temperature)
+	if e.Temperature != 23720*physic.MilliCelsius+physic.ZeroCelsius {
+		t.Fatalf("temp %d", e.Temperature)
 	}
-	if env.Pressure != 100943 {
-		t.Fatalf("pressure %d", env.Pressure)
+	if e.Pressure != 100942695312500*physic.NanoPascal {
+		t.Fatalf("pressure %d", e.Pressure)
 	}
-	if env.Humidity != 6531 {
-		t.Fatalf("humidity %d", env.Humidity)
+	if e.Humidity != 65305*physic.MicroRH {
+		t.Fatalf("humidity %d", e.Humidity)
 	}
 	if err := dev.Halt(); err != nil {
 		t.Fatal(err)
@@ -430,8 +429,8 @@ func TestI2CSense280_idle_fail(t *testing.T) {
 	if s := dev.String(); s != "BME280{playback(118)}" {
 		t.Fatal(s)
 	}
-	env := devices.Environment{}
-	if dev.Sense(&env) == nil {
+	e := physic.Env{}
+	if dev.Sense(&e) == nil {
 		t.Fatal("isIdle() should have failed")
 	}
 }
@@ -466,8 +465,8 @@ func TestI2CSense280_command_fail(t *testing.T) {
 	if s := dev.String(); s != "BME280{playback(118)}" {
 		t.Fatal(s)
 	}
-	env := devices.Environment{}
-	if dev.Sense(&env) == nil {
+	e := physic.Env{}
+	if dev.Sense(&e) == nil {
 		t.Fatal("isIdle() should have failed")
 	}
 }
@@ -511,20 +510,20 @@ func TestI2CSenseContinuous280_success(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	env := devices.Environment{}
+	e := physic.Env{}
 	select {
-	case env = <-c:
+	case e = <-c:
 	case <-time.After(2 * time.Second):
 		t.Fatal("failed")
 	}
-	if env.Temperature != 23720 {
-		t.Fatalf("temp %d", env.Temperature)
+	if e.Temperature != 23720*physic.MilliCelsius+physic.ZeroCelsius {
+		t.Fatalf("temp %d", e.Temperature)
 	}
-	if env.Pressure != 100943 {
-		t.Fatalf("pressure %d", env.Pressure)
+	if e.Pressure != 100942695312500*physic.NanoPascal {
+		t.Fatalf("pressure %d", e.Pressure)
 	}
-	if env.Humidity != 6531 {
-		t.Fatalf("humidity %d", env.Humidity)
+	if e.Humidity != 65305*physic.MicroRH {
+		t.Fatalf("humidity %d", e.Humidity)
 	}
 
 	// This cancels the previous channel and resets the interval.
@@ -537,26 +536,26 @@ func TestI2CSenseContinuous280_success(t *testing.T) {
 		t.Fatal("c should be closed")
 	}
 	select {
-	case env = <-c2:
+	case e = <-c2:
 	case <-time.After(2 * time.Second):
 		t.Fatal("failed")
 	}
 	select {
-	case env = <-c2:
+	case e = <-c2:
 	case <-time.After(2 * time.Second):
 		t.Fatal("failed")
 	}
-	if env.Temperature != 23720 {
-		t.Fatalf("temp %d", env.Temperature)
+	if e.Temperature != 23720*physic.MilliCelsius+physic.ZeroCelsius {
+		t.Fatalf("temp %d", e.Temperature)
 	}
-	if env.Pressure != 100943 {
-		t.Fatalf("pressure %d", env.Pressure)
+	if e.Pressure != 100942695312500*physic.NanoPascal {
+		t.Fatalf("pressure %d", e.Pressure)
 	}
-	if env.Humidity != 6531 {
-		t.Fatalf("humidity %d", env.Humidity)
+	if e.Humidity != 65305*physic.MicroRH {
+		t.Fatalf("humidity %d", e.Humidity)
 	}
 
-	if dev.Sense(&env) == nil {
+	if dev.Sense(&e) == nil {
 		t.Fatal("can't Sense() during SenseContinously")
 	}
 
diff --git a/devices/bmxx80/bmx280smoketest/bmx280smoketest.go b/devices/bmxx80/bmx280smoketest/bmx280smoketest.go
index 9d89639..51857b8 100644
--- a/devices/bmxx80/bmx280smoketest/bmx280smoketest.go
+++ b/devices/bmxx80/bmx280smoketest/bmx280smoketest.go
@@ -15,10 +15,10 @@ import (
 	"periph.io/x/periph/conn/i2c"
 	"periph.io/x/periph/conn/i2c/i2creg"
 	"periph.io/x/periph/conn/i2c/i2ctest"
+	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/conn/spi"
 	"periph.io/x/periph/conn/spi/spireg"
 	"periph.io/x/periph/conn/spi/spitest"
-	"periph.io/x/periph/devices"
 	"periph.io/x/periph/devices/bmxx80"
 )
 
@@ -154,8 +154,8 @@ func run(i2cBus i2c.Bus, i2cAddr uint16, spiPort spi.PortCloser) (err error) {
 		}
 	}()
 
-	i2cEnv := devices.Environment{}
-	spiEnv := devices.Environment{}
+	i2cEnv := physic.Env{}
+	spiEnv := physic.Env{}
 	if err2 := i2cDev.Sense(&i2cEnv); err2 != nil {
 		return err2
 	}
@@ -164,7 +164,7 @@ func run(i2cBus i2c.Bus, i2cAddr uint16, spiPort spi.PortCloser) (err error) {
 		return err2
 	}
 	printEnv(spiDev, &spiEnv)
-	delta := devices.Environment{
+	delta := physic.Env{
 		Temperature: i2cEnv.Temperature - spiEnv.Temperature,
 		Pressure:    i2cEnv.Pressure - spiEnv.Pressure,
 		Humidity:    i2cEnv.Humidity - spiEnv.Humidity,
@@ -186,6 +186,6 @@ func run(i2cBus i2c.Bus, i2cAddr uint16, spiPort spi.PortCloser) (err error) {
 	return nil
 }
 
-func printEnv(dev interface{}, env *devices.Environment) {
-	fmt.Printf("%-18s: %8s %10s %9s\n", dev, env.Temperature, env.Pressure, env.Humidity)
+func printEnv(dev interface{}, e *physic.Env) {
+	fmt.Printf("%-18s: %8s %10s %9s\n", dev, e.Temperature, e.Pressure, e.Humidity)
 }
diff --git a/devices/bmxx80/bmxx80.go b/devices/bmxx80/bmxx80.go
index 5c9201b..09e6eb8 100644
--- a/devices/bmxx80/bmxx80.go
+++ b/devices/bmxx80/bmxx80.go
@@ -38,8 +38,8 @@ import (
 	"periph.io/x/periph/conn"
 	"periph.io/x/periph/conn/i2c"
 	"periph.io/x/periph/conn/mmr"
+	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/conn/spi"
-	"periph.io/x/periph/devices"
 )
 
 // Oversampling affects how much time is taken to measure each of temperature,
@@ -245,7 +245,7 @@ func (d *Dev) String() string {
 // Sense requests a one time measurement as °C, kPa and % of relative humidity.
 //
 // The very first measurements may be of poor quality.
-func (d *Dev) Sense(env *devices.Environment) error {
+func (d *Dev) Sense(e *physic.Env) error {
 	d.mu.Lock()
 	defer d.mu.Unlock()
 	if d.stop != nil {
@@ -266,9 +266,9 @@ func (d *Dev) Sense(env *devices.Environment) error {
 				return d.wrap(err)
 			}
 		}
-		return d.sense280(env)
+		return d.sense280(e)
 	}
-	return d.sense180(env)
+	return d.sense180(e)
 }
 
 // SenseContinuous returns measurements as °C, kPa and % of relative humidity
@@ -279,7 +279,7 @@ func (d *Dev) Sense(env *devices.Environment) error {
 //
 // It's the responsibility of the caller to retrieve the values from the
 // channel as fast as possible, otherwise the interval may not be respected.
-func (d *Dev) SenseContinuous(interval time.Duration) (<-chan devices.Environment, error) {
+func (d *Dev) SenseContinuous(interval time.Duration) (<-chan physic.Env, error) {
 	d.mu.Lock()
 	defer d.mu.Unlock()
 	if d.stop != nil {
@@ -302,7 +302,7 @@ func (d *Dev) SenseContinuous(interval time.Duration) (<-chan devices.Environmen
 		}
 	}
 
-	sensing := make(chan devices.Environment)
+	sensing := make(chan physic.Env)
 	d.stop = make(chan struct{})
 	d.wg.Add(1)
 	go func() {
@@ -433,14 +433,14 @@ func (d *Dev) makeDev(opts *Opts) error {
 	return nil
 }
 
-func (d *Dev) sensingContinuous(interval time.Duration, sensing chan<- devices.Environment, stop <-chan struct{}) {
+func (d *Dev) sensingContinuous(interval time.Duration, sensing chan<- physic.Env, stop <-chan struct{}) {
 	t := time.NewTicker(interval)
 	defer t.Stop()
 
 	var err error
 	for {
 		// Do one initial sensing right away.
-		var e devices.Environment
+		e := physic.Env{}
 		d.mu.Lock()
 		if d.is280 {
 			err = d.sense280(&e)
@@ -514,5 +514,5 @@ var defaults = Opts{
 var doSleep = time.Sleep
 
 var _ conn.Resource = &Dev{}
-var _ devices.Environmental = &Dev{}
+var _ physic.SenseEnv = &Dev{}
 var _ fmt.Stringer = &Dev{}
diff --git a/devices/bmxx80/example_test.go b/devices/bmxx80/example_test.go
index ced88b3..602d72f 100644
--- a/devices/bmxx80/example_test.go
+++ b/devices/bmxx80/example_test.go
@@ -9,7 +9,7 @@ import (
 	"log"
 
 	"periph.io/x/periph/conn/i2c/i2creg"
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/devices/bmxx80"
 	"periph.io/x/periph/host"
 )
@@ -30,7 +30,7 @@ func Example() {
 	if err != nil {
 		log.Fatalf("failed to initialize bme280: %v", err)
 	}
-	e := devices.Environment{}
+	e := physic.Env{}
 	if err := d.Sense(&e); err != nil {
 		log.Fatal(err)
 	}
diff --git a/devices/devices.go b/devices/devices.go
index d3eb19d..a44c76f 100644
--- a/devices/devices.go
+++ b/devices/devices.go
@@ -8,7 +8,6 @@ import (
 	"image"
 	"image/color"
 	"io"
-	"time"
 
 	"periph.io/x/periph/conn"
 )
@@ -41,22 +40,3 @@ type Display interface {
 	// To be compatible with draw.Drawer, this function doesn't return an error.
 	Draw(r image.Rectangle, src image.Image, sp image.Point)
 }
-
-// Environment represents measurements from an environmental sensor.
-//
-// Deprecated: This interface will be removed in v3. Use physic.Env instead.
-type Environment struct {
-	Temperature Celsius
-	Pressure    KPascal
-	Humidity    RelativeHumidity
-}
-
-// Environmental represents an environmental sensor.
-//
-// Deprecated: This interface will be removed in v3. Use physic.SenseEnv
-// instead.
-type Environmental interface {
-	conn.Resource
-	Sense(env *Environment) error
-	SenseContinuous(interval time.Duration) (<-chan Environment, error)
-}
diff --git a/devices/ds18b20/ds18b20.go b/devices/ds18b20/ds18b20.go
index 97434ce..4126ffe 100644
--- a/devices/ds18b20/ds18b20.go
+++ b/devices/ds18b20/ds18b20.go
@@ -28,7 +28,7 @@ import (
 
 	"periph.io/x/periph/conn"
 	"periph.io/x/periph/conn/onewire"
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 )
 
 // ConvertAll performs a conversion on all DS18B20 devices on the bus.
@@ -109,7 +109,7 @@ func (d *Dev) Halt() error {
 }
 
 // Temperature performs a conversion and returns the temperature.
-func (d *Dev) Temperature() (devices.Celsius, error) {
+func (d *Dev) Temperature() (physic.Temperature, error) {
 	if err := d.onewire.TxPower([]byte{0x44}, nil); err != nil {
 		return 0, err
 	}
@@ -121,7 +121,7 @@ func (d *Dev) Temperature() (devices.Celsius, error) {
 // device.
 //
 // It is useful in combination with ConvertAll.
-func (d *Dev) LastTemp() (devices.Celsius, error) {
+func (d *Dev) LastTemp() (physic.Temperature, error) {
 	// Read the scratchpad memory.
 	spad, err := d.readScratchpad()
 	if err != nil {
@@ -129,9 +129,10 @@ func (d *Dev) LastTemp() (devices.Celsius, error) {
 	}
 
 	// spad[1] is MSB, spad[0] is LSB and has 4 fractional bits. Need to do sign
-	// extension multiply by 1000 to get devices.Millis, divide by 16 due to 4
-	// fractional bits.  Datasheet p.4.
-	c := (devices.Celsius(int8(spad[1]))<<8 + devices.Celsius(spad[0])) * 1000 / 16
+	// extension multiply by 1000 to get Millis, divide by 16 due to 4 fractional
+	// bits. Datasheet p.4.
+	v := (int(int8(spad[1]))<<8 + int(spad[0])) * 1000 / 16
+	c := physic.Temperature(v)*physic.MilliKelvin + physic.ZeroCelsius
 
 	// The device powers up with a value of 85°C, so if we read that odds are
 	// very high that either no conversion was performed or that the conversion
diff --git a/devices/ds18b20/ds18b20_test.go b/devices/ds18b20/ds18b20_test.go
index da3fba8..b8a2806 100644
--- a/devices/ds18b20/ds18b20_test.go
+++ b/devices/ds18b20/ds18b20_test.go
@@ -11,7 +11,7 @@ import (
 
 	"periph.io/x/periph/conn/onewire"
 	"periph.io/x/periph/conn/onewire/onewiretest"
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 )
 
 func TestNew_fail_resolution(t *testing.T) {
@@ -52,7 +52,7 @@ func TestTemperature(t *testing.T) {
 		},
 	}
 	var addr onewire.Address = 0x740000070e41ac28
-	var temp devices.Celsius = 30000 // 30.000°C
+	temp := 30*physic.Celsius + physic.ZeroCelsius
 	bus := onewiretest.Playback{Ops: ops}
 	dev, err := New(&bus, addr, 10)
 	if err != nil {
@@ -187,7 +187,7 @@ func TestRecordTemp(t *testing.T) {
 		t.Logf("  %#v,", op)
 	}
 	t.Log("}")
-	t.Logf("var temp devices.Celsius = %d // %s", temp, temp.String())
+	t.Logf("var temp physic.Temperature = %d  // %s", temp, temp.String())
 }
 
 //
diff --git a/devices/lepton/cci/cci.go b/devices/lepton/cci/cci.go
index 48b8f89..f40a7a8 100644
--- a/devices/lepton/cci/cci.go
+++ b/devices/lepton/cci/cci.go
@@ -31,7 +31,7 @@ import (
 	"periph.io/x/periph/conn"
 	"periph.io/x/periph/conn/i2c"
 	"periph.io/x/periph/conn/mmr"
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/devices/lepton/internal"
 )
 
@@ -132,7 +132,7 @@ type FFCMode struct {
 	ShutterTempLockoutState ShutterTempLockoutState // Default: ShutterTempLockoutStateInactive
 	ElapsedTimeSinceLastFFC time.Duration           // Uptime
 	DesiredFFCPeriod        time.Duration           // Default: 300s
-	DesiredFFCTempDelta     devices.Celsius         // Default: 3K
+	DesiredFFCTempDelta     physic.Temperature      // Default: 3K
 	ImminentDelay           uint16                  // Default: 52
 	VideoFreezeDuringFFC    bool                    // Default: true
 	FFCDesired              bool                    // Default: false
@@ -256,25 +256,25 @@ func (d *Dev) GetUptime() (time.Duration, error) {
 	if err := d.c.get(sysUptime, &v); err != nil {
 		return 0, err
 	}
-	return v.ToD(), nil
+	return v.Duration(), nil
 }
 
 // GetTemp returns the temperature inside the camera.
-func (d *Dev) GetTemp() (devices.Celsius, error) {
+func (d *Dev) GetTemp() (physic.Temperature, error) {
 	var v internal.CentiK
 	if err := d.c.get(sysTemperature, &v); err != nil {
 		return 0, err
 	}
-	return v.ToC(), nil
+	return v.Temperature(), nil
 }
 
 // GetTempHousing returns the temperature of the camera housing.
-func (d *Dev) GetTempHousing() (devices.Celsius, error) {
+func (d *Dev) GetTempHousing() (physic.Temperature, error) {
 	var v internal.CentiK
 	if err := d.c.get(sysHousingTemperature, &v); err != nil {
 		return 0, err
 	}
-	return v.ToC(), nil
+	return v.Temperature(), nil
 }
 
 // GetFFCModeControl returns the internal state with regards to calibration.
@@ -286,9 +286,9 @@ func (d *Dev) GetFFCModeControl() (*FFCMode, error) {
 	return &FFCMode{
 		FFCShutterMode:          FFCShutterMode(v.FFCShutterMode),
 		ShutterTempLockoutState: ShutterTempLockoutState(v.ShutterTempLockoutState),
-		ElapsedTimeSinceLastFFC: v.ElapsedTimeSinceLastFFC.ToD(),
-		DesiredFFCPeriod:        v.DesiredFFCPeriod.ToD(),
-		DesiredFFCTempDelta:     devices.Celsius(v.DesiredFFCTempDelta * 10),
+		ElapsedTimeSinceLastFFC: v.ElapsedTimeSinceLastFFC.Duration(),
+		DesiredFFCPeriod:        v.DesiredFFCPeriod.Duration(),
+		DesiredFFCTempDelta:     v.DesiredFFCTempDelta.Temperature(),
 		ImminentDelay:           v.ImminentDelay,
 		VideoFreezeDuringFFC:    v.VideoFreezeDuringFFC == internal.Enabled,
 		FFCDesired:              v.FFCDesired == internal.Enabled,
diff --git a/devices/lepton/internal/internal.go b/devices/lepton/internal/internal.go
index 0895478..371dcd2 100644
--- a/devices/lepton/internal/internal.go
+++ b/devices/lepton/internal/internal.go
@@ -8,7 +8,7 @@ import (
 	"encoding/binary"
 	"time"
 
-	"periph.io/x/periph/devices"
+	"periph.io/x/periph/conn/physic"
 )
 
 // Flag is used in FFCMode.
@@ -25,8 +25,8 @@ const (
 // It is an implementation detail of the protocol.
 type DurationMS uint32
 
-// ToD converts a millisecond based timing to time.Duration.
-func (d DurationMS) ToD() time.Duration {
+// Duration converts a millisecond based timing to time.Duration.
+func (d DurationMS) Duration() time.Duration {
 	return time.Duration(d) * time.Millisecond
 }
 
@@ -35,10 +35,9 @@ func (d DurationMS) ToD() time.Duration {
 // It is an implementation detail of the protocol.
 type CentiK uint16
 
-// ToC converts a Kelvin measurement to Celsius.
-func (c CentiK) ToC() devices.Celsius {
-	v := (int(c) - 27315) * 10
-	return devices.Celsius(v)
+// Temperature converts a Kelvin measurement to Temperature.
+func (c CentiK) Temperature() physic.Temperature {
+	return physic.Temperature(c) * 10 * physic.MilliKelvin
 }
 
 // Status returns the camera status as returned by the camera.
@@ -57,7 +56,7 @@ type FFCMode struct {
 	ElapsedTimeSinceLastFFC DurationMS // Uptime in ms.
 	DesiredFFCPeriod        DurationMS // Default: 300000
 	ExplicitCommandToOpen   Flag       // Default: Disabled
-	DesiredFFCTempDelta     uint16     // Default: 300
+	DesiredFFCTempDelta     CentiK     // Default: 300
 	ImminentDelay           uint16     // Default: 52
 
 	// These are documented at page 51 but not listed in the structure.
diff --git a/devices/lepton/internal/internal_test.go b/devices/lepton/internal/internal_test.go
index f070d22..774e0ba 100644
--- a/devices/lepton/internal/internal_test.go
+++ b/devices/lepton/internal/internal_test.go
@@ -8,16 +8,18 @@ import (
 	"bytes"
 	"testing"
 	"time"
+
+	"periph.io/x/periph/conn/physic"
 )
 
 func TestDuration(t *testing.T) {
-	if d := DurationMS(100).ToD(); d != 100*time.Millisecond {
+	if d := DurationMS(100).Duration(); d != 100*time.Millisecond {
 		t.Fatal(d)
 	}
 }
 
 func TestCentiK(t *testing.T) {
-	if c := CentiK(100).ToC(); c != -272150 {
+	if c := CentiK(100).Temperature(); c != physic.Kelvin {
 		t.Fatal(c)
 	}
 }
diff --git a/devices/lepton/lepton.go b/devices/lepton/lepton.go
index d51ffdd..99c5c3f 100644
--- a/devices/lepton/lepton.go
+++ b/devices/lepton/lepton.go
@@ -29,27 +29,27 @@ import (
 	"periph.io/x/periph/conn"
 	"periph.io/x/periph/conn/gpio"
 	"periph.io/x/periph/conn/i2c"
+	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/conn/spi"
-	"periph.io/x/periph/devices"
 	"periph.io/x/periph/devices/lepton/cci"
 	"periph.io/x/periph/devices/lepton/internal"
 )
 
 // Metadata is constructed from telemetry data, which is sent with each frame.
 type Metadata struct {
-	SinceStartup   time.Duration   //
-	FrameCount     uint32          // Number of frames since the start of the camera, in 27fps (not 9fps).
-	AvgValue       uint16          // Average value of the buffer.
-	Temp           devices.Celsius // Temperature inside the camera.
-	TempHousing    devices.Celsius // Camera housing temperature.
-	RawTemp        uint16          //
-	RawTempHousing uint16          //
-	FFCSince       time.Duration   // Time since last internal calibration.
-	FFCTemp        devices.Celsius // Temperature at last internal calibration.
-	FFCTempHousing devices.Celsius //
-	FFCState       cci.FFCState    // Current calibration state.
-	FFCDesired     bool            // Asserted at start-up, after period (default 3m) or after temperature change (default 3K). Indicates that a calibration should be triggered as soon as possible.
-	Overtemp       bool            // true 10s before self-shutdown.
+	SinceStartup   time.Duration      //
+	FrameCount     uint32             // Number of frames since the start of the camera, in 27fps (not 9fps).
+	AvgValue       uint16             // Average value of the buffer.
+	Temp           physic.Temperature // Temperature inside the camera.
+	TempHousing    physic.Temperature // Camera housing temperature.
+	RawTemp        uint16             //
+	RawTempHousing uint16             //
+	FFCSince       time.Duration      // Time since last internal calibration.
+	FFCTemp        physic.Temperature // Temperature at last internal calibration.
+	FFCTempHousing physic.Temperature //
+	FFCState       cci.FFCState       // Current calibration state.
+	FFCDesired     bool               // Asserted at start-up, after period (default 3m) or after temperature change (default 3K). Indicates that a calibration should be triggered as soon as possible.
+	Overtemp       bool               // true 10s before self-shutdown.
 }
 
 // Frame is a FLIR Lepton frame, containing 14 bits resolution intensity stored
@@ -334,16 +334,16 @@ func (m *Metadata) parseTelemetry(data []byte) error {
 	if err := binary.Read(bytes.NewBuffer(data), internal.Big16, &rowA); err != nil {
 		return err
 	}
-	m.SinceStartup = rowA.TimeCounter.ToD()
+	m.SinceStartup = rowA.TimeCounter.Duration()
 	m.FrameCount = rowA.FrameCounter
 	m.AvgValue = rowA.FrameMean
-	m.Temp = rowA.FPATemp.ToC()
-	m.TempHousing = rowA.HousingTemp.ToC()
+	m.Temp = rowA.FPATemp.Temperature()
+	m.TempHousing = rowA.HousingTemp.Temperature()
 	m.RawTemp = rowA.FPATempCounts
 	m.RawTempHousing = rowA.HousingTempCounts
-	m.FFCSince = rowA.TimeCounterLastFFC.ToD()
-	m.FFCTemp = rowA.FPATempLastFFC.ToC()
-	m.FFCTempHousing = rowA.HousingTempLastFFC.ToC()
+	m.FFCSince = rowA.TimeCounterLastFFC.Duration()
+	m.FFCTemp = rowA.FPATempLastFFC.Temperature()
+	m.FFCTempHousing = rowA.HousingTempLastFFC.Temperature()
 	if rowA.StatusBits&statusMaskNil != 0 {
 		return fmt.Errorf("lepton: (Status: 0x%08X) & (Mask: 0x%08X) = (Extra: 0x%08X) in 0x%08X", rowA.StatusBits, statusMask, rowA.StatusBits&statusMaskNil, statusMaskNil)
 	}
diff --git a/devices/lepton/lepton_test.go b/devices/lepton/lepton_test.go
index 423346e..90e7bb5 100644
--- a/devices/lepton/lepton_test.go
+++ b/devices/lepton/lepton_test.go
@@ -18,9 +18,9 @@ import (
 	"periph.io/x/periph/conn/gpio"
 	"periph.io/x/periph/conn/gpio/gpiotest"
 	"periph.io/x/periph/conn/i2c/i2ctest"
+	"periph.io/x/periph/conn/physic"
 	"periph.io/x/periph/conn/spi"
 	"periph.io/x/periph/conn/spi/spitest"
-	"periph.io/x/periph/devices"
 	"periph.io/x/periph/devices/lepton/internal"
 )
 
@@ -192,7 +192,7 @@ func TestNextFrame(t *testing.T) {
 	if err := d.NextFrame(&f); err != nil {
 		t.Fatal(err)
 	}
-	if f.Metadata.TempHousing != devices.Celsius(2000) {
+	if f.Metadata.TempHousing != 2*physic.Celsius+physic.ZeroCelsius {
 		t.Fatal(f.Metadata.TempHousing)
 	}
 	// Compare the frame with the reference image. It should match.
@@ -268,7 +268,7 @@ func TestReadImg(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if f.Metadata.TempHousing != devices.Celsius(2000) {
+	if f.Metadata.TempHousing != 2*physic.Celsius+physic.ZeroCelsius {
 		t.Fatal(f.Metadata.TempHousing)
 	}
 	if err := i.Close(); err != nil {
diff --git a/devices/units.go b/devices/units.go
deleted file mode 100644
index f29dc28..0000000
--- a/devices/units.go
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright 2016 The Periph Authors. All rights reserved.
-// Use of this source code is governed under the Apache License, Version 2.0
-// that can be found in the LICENSE file.
-
-package devices
-
-import (
-	"strconv"
-)
-
-// Milli is a fixed point value with 0.001 precision.
-//
-// Deprecated: This interface will be removed in v3.
-type Milli int32
-
-// Float64 returns the value as float64 with 0.001 precision.
-func (m Milli) Float64() float64 {
-	return float64(m) * .001
-}
-
-// String returns the value formatted as a string.
-func (m Milli) String() string {
-	d := m % 1000
-	if d < 0 {
-		d = -d
-	}
-	return strconv.Itoa(int(m)/1000) + "." + prefixZeros(3, int(d))
-}
-
-// Celsius is a temperature at a precision of 0.001°C.
-//
-// Deprecated: This interface will be removed in v3. Use physic.Temperature
-// instead.
-type Celsius Milli
-
-// Float64 returns the value as float64 with 0.001 precision.
-func (c Celsius) Float64() float64 {
-	return Milli(c).Float64()
-}
-
-// String returns the temperature formatted as a string.
-func (c Celsius) String() string {
-	return Milli(c).String() + "°C"
-}
-
-// ToF returns the temperature as Fahrenheit, a unit used in the United States.
-func (c Celsius) ToF() Fahrenheit {
-	return Fahrenheit((c*9+2)/5 + 32000)
-}
-
-// Fahrenheit is an unsound unit used in the United States.
-//
-// Deprecated: This interface will be removed in v3. Use physic.Temperature
-// instead.
-type Fahrenheit Milli
-
-// Float64 returns the value as float64 with 0.001 precision.
-func (f Fahrenheit) Float64() float64 {
-	return Milli(f).Float64()
-}
-
-// String returns the temperature formatted as a string.
-func (f Fahrenheit) String() string {
-	return Milli(f).String() + "°F"
-}
-
-// KPascal is pressure at precision of 1Pa.
-//
-// Deprecated: This interface will be removed in v3. Use physic.Pressure
-// instead.
-type KPascal Milli
-
-// Float64 returns the value as float64 with 0.001 precision.
-func (k KPascal) Float64() float64 {
-	return Milli(k).Float64()
-}
-
-// String returns the pressure formatted as a string.
-func (k KPascal) String() string {
-	return Milli(k).String() + "KPa"
-}
-
-// RelativeHumidity is humidity level in %rH with 0.01%rH precision.
-//
-// Deprecated: This interface will be removed in v3. Use
-// physic.RelativeHumidity instead.
-type RelativeHumidity int32
-
-// Float64 returns the value in %.
-func (r RelativeHumidity) Float64() float64 {
-	return float64(r) * .01
-}
-
-// String returns the humidity formatted as a string.
-func (r RelativeHumidity) String() string {
-	m := r % 100
-	if m < 0 {
-		m = -m
-	}
-	return strconv.Itoa(int(r)/100) + "." + prefixZeros(2, int(m)) + "%rH"
-}
-
-//
-
-func prefixZeros(digits, v int) string {
-	// digits is expected to be around 2~3.
-	s := strconv.Itoa(v)
-	for len(s) < digits {
-		// O(n²) but since digits is expected to run 2~3 times at most, it doesn't matter.
-		s = "0" + s
-	}
-	return s
-}
diff --git a/devices/units_test.go b/devices/units_test.go
deleted file mode 100644
index 5a98830..0000000
--- a/devices/units_test.go
+++ /dev/null
@@ -1,80 +0,0 @@
-// Copyright 2016 The Periph Authors. All rights reserved.
-// Use of this source code is governed under the Apache License, Version 2.0
-// that can be found in the LICENSE file.
-
-package devices
-
-import "testing"
-
-func TestMilli(t *testing.T) {
-	o := Milli(10010)
-	if s := o.String(); s != "10.010" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f > 10.011 || f < 10.009 {
-		t.Fatalf("%f", f)
-	}
-}
-
-func TestMilli_neg(t *testing.T) {
-	o := Milli(-10010)
-	if s := o.String(); s != "-10.010" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f > -10.009 || f < -10.011 {
-		t.Fatalf("%f", f)
-	}
-}
-
-func TestCelsius(t *testing.T) {
-	o := Celsius(10010)
-	if s := o.String(); s != "10.010°C" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f > 10.011 || f < 10.009 {
-		t.Fatalf("%f", f)
-	}
-	if f := o.ToF(); f != 50018 {
-		t.Fatalf("%d", f)
-	}
-}
-
-func TestFahrenheit(t *testing.T) {
-	o := Fahrenheit(10010)
-	if s := o.String(); s != "10.010°F" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f > 10.011 || f < 10.009 {
-		t.Fatalf("%f", f)
-	}
-}
-
-func TestKPascal(t *testing.T) {
-	o := KPascal(10010)
-	if s := o.String(); s != "10.010KPa" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f > 10.011 || f < 10.009 {
-		t.Fatalf("%f", f)
-	}
-}
-
-func TestRelativeHumidity(t *testing.T) {
-	o := RelativeHumidity(5006)
-	if s := o.String(); s != "50.06%rH" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f >= 50.07 || f <= 50.05 {
-		t.Fatalf("%f", f)
-	}
-}
-
-func TestRelativeHumidity_neg(t *testing.T) {
-	o := RelativeHumidity(-5010)
-	if s := o.String(); s != "-50.10%rH" {
-		t.Fatalf("%#v", s)
-	}
-	if f := o.Float64(); f <= -50.11 || f >= -50.09 {
-		t.Fatalf("%f", f)
-	}
-}