Ensure atomicity, update README and improve examples.

README.rst

@@ -14,6 +14,7 @@ To install, just click **Download ZIP** and install it using **Sketch > Include
 The following examples_ are provided:
 
 * Fade_ Arduino Fade example using an AC lamp.
+* FadeMinimum_ Arduino Fade example using an AC lamp and setting a minimum power level (useful for dimmable LED or CFL lamps).
 * RandomLamps_ Control 3 dimmable lamps with random values (can be extended to 10 lamps).
 * WaveLamps_ Control 3 dimmable lamps in a wave form (can be extended to 10 lamps).
 * CountMode_ Control high, low response AC loads without introducing noise using count mode.
@@ -23,6 +24,7 @@ The following examples_ are provided:
 .. _Circuitar: https://www.circuitar.com/
 .. _examples: https://github.com/circuitar/Dimmer/tree/master/examples/
 .. _Fade: https://github.com/circuitar/Dimmer/blob/master/examples/Fade/Fade.ino
+.. _FadeMinimum: https://github.com/circuitar/Dimmer/blob/master/examples/FadeMinimum/FadeMinimum.ino
 .. _RandomLamps: https://github.com/circuitar/Dimmer/blob/master/examples/RandomLamps/RandomLamps.ino
 .. _WaveLamps: https://github.com/circuitar/Dimmer/blob/master/examples/WaveLamps/WaveLamps.ino
 .. _CountMode: https://github.com/circuitar/Dimmer/blob/master/examples/CountMode/CountMode.ino

examples/FadeMinimum/FadeMinimum.ino

@@ -12,12 +12,12 @@ Dimmer dimmer(3, DIMMER_RAMP, 1.5);
 
 void setup() {
   dimmer.begin();
-  dimmer.setMinimum(25);
+  dimmer.setMinimum(20);
 }
 
 void loop() {
   dimmer.set(100);
-  delay(1500);
+  delay(2500);
   dimmer.set(0);
-  delay(1500);
+  delay(2500);
 }

src/Dimmer.cpp

@@ -7,6 +7,7 @@
 
 #include "Arduino.h"
 #include "Dimmer.h"
+#include <util/atomic.h>
 
 // Timer configuration macros
 #define _TCNT(X) TCNT ## X
@@ -154,15 +155,19 @@ void Dimmer::on() {
 }
 
 void Dimmer::toggle() {
-  lampState = !lampState;
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    lampState = !lampState;
+  }
 }
 
 bool Dimmer::getState() {
   return lampState;
 }
 
 uint8_t Dimmer::getValue() {
-  return rampStartValue + ((int32_t) lampValue - rampStartValue) * rampCounter / rampCycles;
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    return rampStartValue + ((int32_t) lampValue - rampStartValue) * rampCounter / rampCycles;
+  }
 }
 
 void Dimmer::set(uint8_t value) {
@@ -174,14 +179,16 @@ void Dimmer::set(uint8_t value) {
     value = minValue;
   }
 
-  if (operatingMode == DIMMER_RAMP) {
-    rampStartValue = getValue();
-    rampCounter = 0;
-  } else if (operatingMode == DIMMER_COUNT) {
-    pulses = 0;
-    pulseCount = 0;
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    if (operatingMode == DIMMER_RAMP) {
+      rampStartValue = getValue();
+      rampCounter = 0;
+    } else if (operatingMode == DIMMER_COUNT) {
+      pulses = 0;
+      pulseCount = 0;
+    }
+    lampValue = value;
   }
-  lampValue = value;
 }
 
 void Dimmer::set(uint8_t value, bool on) {
@@ -196,8 +203,10 @@ void Dimmer::setMinimum(uint8_t value) {
 
   minValue = value;
 
-  if (lampValue < minValue) {
-    set(value);
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    if (lampValue < minValue) {
+      set(value);
+    }
   }
 }