make SetCriticalTempLock and SetWindowTempLock exported and don't auto lock when setting temps since the device doesn't seem to respond well to it

samples/mcp9808.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"fmt"
 	"os"
-	"time"
 
 	"github.com/kidoman/embd"
 	_ "github.com/kidoman/embd/host/rpi"
@@ -28,6 +27,8 @@ func main() {
 	}
 
 	therm.SetShutdownMode(false)
+	therm.SetCriticalTempLock(false)
+	therm.SetWindowTempLock(false)
 	therm.SetAlertMode(true)
 	therm.SetInterruptClear(true)
 	therm.SetAlertStatus(true)
@@ -35,6 +36,9 @@ func main() {
 	therm.SetAlertSelect(false)
 	therm.SetAlertPolarity(true)
 
+	// get faster results (130ms vs 250ms default)
+	therm.SetTempResolution(mcp9808.EighthC)
+
 	config, _ := therm.Config()
 	fmt.Printf("New Config: %b\n", config)
 
@@ -47,7 +51,7 @@ func main() {
 	}
 	fmt.Printf("Critical Temp set to: %fC\n", critTemp)
 
-	if err := therm.SetWindowTempLower(TempFToC(50)); err != nil {
+	if err := therm.SetWindowTempLower(TempFToC(60)); err != nil {
 		panic(err)
 	}
 	lowerTemp, err := therm.WindowTempLower()
@@ -62,6 +66,9 @@ func main() {
 	upperTemp, _ := therm.WindowTempUpper()
 	fmt.Printf("Upper Temp Limit set to: %fC\n", upperTemp)
 
+	therm.SetCriticalTempLock(true)
+	therm.SetWindowTempLock(true)
+
 	alert, err := embd.NewDigitalPin(23)
 	if err != nil {
 		panic(err)
@@ -87,10 +94,11 @@ func main() {
 		cancel <- true
 	}()
 
-	timer := time.Tick(time.Duration(5) * time.Second)
 	for {
 		select {
-		case <-timer:
+		case <-cancel:
+			return
+		default:
 			temp, err := therm.AmbientTemp()
 			if err != nil {
 				fmt.Printf("Error reading temp: %s\n", err.Error())
@@ -98,8 +106,6 @@ func main() {
 				fmt.Printf("Current temp is: %fF (%fC), Window Alert: %v, Critical Alert: %v\n",
 					TempCToF(temp.CelsiusDeg), temp.CelsiusDeg, temp.AboveUpper || temp.BelowLower, temp.AboveCritical)
 			}
-		case <-cancel:
-			return
 		}
 	}
 }

sensor/mcp9808/mcp9808.go

@@ -164,7 +164,7 @@ func (d *MCP9808) CriticalTempLock() (bool, error) {
 // 1 (true) = Locked. TCRIT register can not be written
 // When enabled, this bit remains set to ‘1’ or locked until cleared by an internal Reset
 // This bit can be programmed in Shutdown mode.
-func (d *MCP9808) setCriticalTempLock(locked bool) error {
+func (d *MCP9808) SetCriticalTempLock(locked bool) error {
 	return d.flipConfigBit(configCriticalTempLock, locked)
 }
 
@@ -176,12 +176,12 @@ func (d *MCP9808) WindowTempLock() (bool, error) {
 	return d.readConfigValue(configWindowTempLock)
 }
 
-// setWindowTempLock - TUPPER and TLOWER Window Lock bit
+// SetWindowTempLock - TUPPER and TLOWER Window Lock bit
 // 0 (false) = Unlocked; TUPPER and TLOWER registers can be written (power-up default)
 // 1 (true) = Locked; TUPPER and TLOWER registers can not be written
 // When enabled, this bit remains set to ‘1’ or locked until cleared by a Power-on Reset
 // This bit can be programmed in Shutdown mode.
-func (d *MCP9808) setWindowTempLock(locked bool) error {
+func (d *MCP9808) SetWindowTempLock(locked bool) error {
 	return d.flipConfigBit(configWindowTempLock, locked)
 }
 
@@ -329,17 +329,9 @@ func (d *MCP9808) CriticalTemp() (float64, error) {
 }
 
 // SetCriticalTemp when the temperature goes above the set value the alert will be
-// triggered if enabled.
+// triggered if enabled.  This has no effect if CriticalTempLock is set.
 func (d *MCP9808) SetCriticalTemp(newTemp float64) error {
-	if err := d.setCriticalTempLock(false); err != nil {
-		return err
-	}
-
-	if err := d.setTemp(regCriticalTemp, newTemp); err != nil {
-		return err
-	}
-
-	return d.setCriticalTempLock(true)
+	return d.setTemp(regCriticalTemp, newTemp)
 }
 
 // WindowTempUpper reads the current temperature set in the upper window temperature register.
@@ -348,17 +340,9 @@ func (d *MCP9808) WindowTempUpper() (float64, error) {
 }
 
 // SetWindowTempUpper when the temperature goes above the set value the alert will be
-// triggered if enabled.
+// triggered if enabled.  This has no effect if WindowTempLock is set.
 func (d *MCP9808) SetWindowTempUpper(newTemp float64) error {
-	if err := d.setWindowTempLock(false); err != nil {
-		return err
-	}
-
-	if err := d.setTemp(regUpperTemp, newTemp); err != nil {
-		return err
-	}
-
-	return d.setWindowTempLock(true)
+	return d.setTemp(regUpperTemp, newTemp)
 }
 
 // WindowTempLower reads the current temperature set in the lower window temperature register.
@@ -367,17 +351,9 @@ func (d *MCP9808) WindowTempLower() (float64, error) {
 }
 
 // SetWindowTempLower when the temperature goes below the set value the alert will be
-// triggered if enabled.
+// triggered if enabled.  This has no effect if WindowTempLock is set.
 func (d *MCP9808) SetWindowTempLower(newTemp float64) error {
-	if err := d.setWindowTempLock(false); err != nil {
-		return err
-	}
-
-	if err := d.setTemp(regLowerTemp, newTemp); err != nil {
-		return err
-	}
-
-	return d.setWindowTempLock(true)
+	return d.setTemp(regLowerTemp, newTemp)
 }
 
 // TempResolution reads the current temperature accuracy from the sensor (affects temperature read speed)