BH1750 ambient light sensor

include/EEPROMAnything.h

@@ -67,9 +67,9 @@ void read() {
     Serial.printf("MQTT_Topic    : %s\n", G.mqtt.topic);
     Serial.printf("MQTT_Port    : %u\n", G.mqtt.port);
 
-    Serial.printf("autoLdrEnabled    : %u\n", G.autoLdrEnabled);
-    Serial.printf("autoLdrBright    : %u\n", G.autoLdrBright);
-    Serial.printf("autoLdrDark    : %u\n", G.autoLdrDark);
+    Serial.printf("autoBrightEnabled    : %u\n", G.autoBrightEnabled);
+    Serial.printf("autoBrightOffset    : %u\n", G.autoBrightOffset);
+    Serial.printf("autoBrightSlope    : %u\n", G.autoBrightSlope);
     Serial.printf("Uhrtype    : %u\n", G.transitionDuration);
     Serial.printf("transitionType    : %u\n", G.transitionType);
     Serial.printf("transitionDuration    : %u\n", G.transitionSpeed);

include/Uhr.h

@@ -127,9 +127,9 @@ struct GLOBAL {
 
     OpenWeatherMapData openWeatherMap;
 
-    uint8_t autoLdrEnabled;
-    uint8_t autoLdrBright;
-    uint8_t autoLdrDark;
+    uint8_t autoBrightEnabled;
+    uint8_t autoBrightOffset;
+    uint8_t autoBrightSlope;
     uint8_t transitionType;
     uint8_t transitionDuration;
     uint8_t transitionSpeed;
@@ -146,7 +146,7 @@ struct GLOBAL {
 GLOBAL G = {};
 
 // LDR
-uint8_t ldrVal = 100;
+float ledGain = 100;
 
 uint8_t _second = 0;
 uint8_t _secondFrame = 0;
@@ -241,7 +241,7 @@ enum CommandWords {
     COMMAND_SET_WIFI_AND_RESTART = 99,
     COMMAND_RESET = 100,
     COMMAND_SET_BOOT = 101,
-    COMMAND_SET_AUTO_LDR = 102,
+    COMMAND_SET_AUTO_BRIGHT = 102,
     COMMAND_SET_LAYOUT_VARIANT = 103,
     COMMAND_SET_MQTT_HA_DISCOVERY = 104,
 
@@ -252,7 +252,7 @@ enum CommandWords {
     COMMAND_REQUEST_CONFIG_VALUES = 200,
     COMMAND_REQUEST_COLOR_VALUES = 201,
     COMMAND_REQUEST_WIFI_LIST = 202,
-    COMMAND_REQUEST_AUTO_LDR = 203,
+    COMMAND_REQUEST_AUTO_BRIGHT = 203,
     COMMAND_REQUEST_TRANSITION = 204,
     COMMAND_REQUEST_MQTT_VALUES = 205,
     COMMAND_REQUEST_BIRTHDAYS = 206,

include/clockWork.h

@@ -6,12 +6,21 @@ class ClockWork {
 private:
     uint16_t countMillisSpeed = 0;
     uint32_t previousMillis = 0;
+    enum class stateBH1750Type {
+    toBeInitialized = 0,
+    Initialized = 1,
+    cannotBeInitialized = 2,
+    };
+    stateBH1750Type stateBH1750 = stateBH1750Type::toBeInitialized;
+    float lux = 0.0;
+    uint16 adcValue0Lux = 10; // Hier wird der niedrigste LDR-ADC Wert getrackt, für eine dynamische offset korrektur bei 0 LUX
 
 private:
     //------------------------------------------------------------------------------
     // Helper Functions
     //------------------------------------------------------------------------------
-    void loopLdrLogic();
+    void initBH1750Logic();
+    void loopAutoBrightLogic();
     uint32_t num32BitWithOnesAccordingToColumns();
     bool isRomanLanguage();
 
@@ -52,7 +61,7 @@ class ClockWork {
     void clearClockByProgInit();
 
 public:
-    ClockWork() = default;
+    //ClockWork() = default;
     ~ClockWork() = default;
 
     //------------------------------------------------------------------------------

include/clockWork.hpp

@@ -5,37 +5,78 @@
 #include "clockWork.h"
 #include "openwmap.h"
 #include <Arduino.h>
+#include <BH1750.h>
 
 OpenWMap weather;
+BH1750 lightMeter(0x23);
 
 //------------------------------------------------------------------------------
 // Helper Functions
 //------------------------------------------------------------------------------
 
-void ClockWork::loopLdrLogic() {
-    int16_t lux = analogRead(A0); // Range 0-1023
-    uint8_t ldrValOld = ldrVal;
-
-    if (G.autoLdrEnabled) {
-        lux /= 4;
-        uint16_t minimum = min(G.autoLdrBright, G.autoLdrDark);
-        uint16_t maximum = max(G.autoLdrBright, G.autoLdrDark);
-        if (lux >= maximum)
-            lux = maximum;
-        if (lux <= minimum)
-            lux = minimum;
-        if (G.autoLdrDark == G.autoLdrBright) {
-            // map() //Would crash with division by zero
-            ldrVal = 100;
+// Automatic Brightness Control (enabled/dieabled by G.autoBrightEnabled)
+// 1. Measure ambient light with high resolution sensor BH1750, if available. If not, use legacy LDR.
+// 2. Derive the ledGain for the LEDs 0.0 - 100.0%
+// 3. When ledGain changed, execute led.set()
+// Inputs: autoBrightSlope, autoBrightOffset 0-255
+// Outputs: 
+//  lux = Ambient light [LUX] 
+//  ledGain = gain for the the LEDs: 0.0-100.0% (Gain means n % of the configured brightness: effectBri)
+void ClockWork::loopAutoBrightLogic() {
+    float ledGainOld = ledGain;
+    if (stateBH1750 == stateBH1750Type::toBeInitialized) {
+        initBH1750Logic();
+    }
+    if (G.autoBrightEnabled) {
+        if (stateBH1750 == stateBH1750Type::Initialized) {
+            // Using BH1750 for ambient light measurement which directly provides the LUX value with high resolution!
+            if (lightMeter.measurementReady())
+                lux = lightMeter.readLightLevel(); // 0.0-54612.5 LUX
         } else {
-            ldrVal = map(lux, G.autoLdrDark, G.autoLdrBright, 10, 100);
+            // Using legacy LDR for ambient light measurement
+            // Electrical circuit = voltage divider: 3.3V--LDR-->ADC<--220 Ohm--GND
+            uint16 adcValue = analogRead(A0); // Read out ADC, pin TOUT = 0.0V - 1.0V = adcValue 0-1023
+            // Track lowest ADC value for offest correction at 0 LUX
+            if (adcValue < adcValue0Lux)
+                adcValue0Lux = adcValue;
+            float ldrValue = adcValue - adcValue0Lux;
+            // Derive LUX value from ldrValue via a second degree polinomial.
+            // The polinomial was derived using an Excel trend line, see LDR-Calibration.xlsx
+            const float x2 = 0.0427;
+            const float x1 = 2.679;
+            const float x0 = 10.857;
+            lux = x2 * ldrValue * ldrValue + x1 * ldrValue + x0;
         }
+
+        // Based on the LUX value derive the gain for the LEDs 0.0 - 100.0%
+        // Interpretation of autoBrightSlope+1=aBS: aBS=1 -> slope=1/16x, aBS=16 -> slope=1x, aBS=256 -> slope=16x, 
+        // When autoBrightOffset=0, and aBS=16 then ledGain should reach 100.0% at 500.0 LUX.
+        ledGain = (lux * (float)(G.autoBrightSlope+1)) / 80.0;
+        // Add autoBrightOffset 0-255
+        ledGain += ((uint16)100*(uint16)G.autoBrightOffset)/(uint16)255;
+        if (ledGain > 100.0) ledGain = 100.0;
     }
-    if (ldrValOld != ldrVal) {
+    if (ledGainOld != ledGain) {
         led.set();
     }
 }
 
+// Ambient Light Sensor BH1750
+// Initialize the I2C bus using SCL and SDA pins
+// (BH1750 library doesn't do this automatically)
+void ClockWork::initBH1750Logic() {
+    Wire.begin(D4,D3);
+    // begin returns a boolean that can be used to detect setup problems.
+    if (lightMeter.begin(BH1750::CONTINUOUS_HIGH_RES_MODE)) {
+      Serial.println("BH1750 initialized. Using this sensor for ambient light measurement.");
+      stateBH1750 = stateBH1750Type::Initialized;
+    } else {
+      Serial.println("BH1750 initialisation error. Using legacy LDR for ambient light measurement");
+      stateBH1750 = stateBH1750Type::cannotBeInitialized;
+    }
+}
+
+
 //------------------------------------------------------------------------------
 
 iUhrType *ClockWork::getPointer(uint8_t type) {
@@ -943,10 +984,10 @@ void ClockWork::loop(struct tm &tm) {
         }
 
         //--------------------------------------------
-        // LDR Routine
+        // Auto Brightness Logic
         //--------------------------------------------
-        if (G.autoLdrEnabled) {
-            loopLdrLogic();
+        if (G.autoBrightEnabled) {
+            loopAutoBrightLogic();
         }
 
         if (G.prog == COMMAND_IDLE && G.conf == 0) {
@@ -1044,7 +1085,7 @@ void ClockWork::loop(struct tm &tm) {
         config["bootLedSweep"] = G.bootLedSweep;
         config["bootShowWifi"] = G.bootShowWifi;
         config["bootShowIP"] = G.bootShowIP;
-        config["autoLdrEnabled"] = G.autoLdrEnabled;
+        config["autoBrightEnabled"] = G.autoBrightEnabled;
         config["isRomanLanguage"] = isRomanLanguage();
         config["hasDreiviertel"] = usedUhrType->hasDreiviertel();
         config["hasZwanzig"] = usedUhrType->hasZwanzig();
@@ -1101,15 +1142,17 @@ void ClockWork::loop(struct tm &tm) {
         break;
     }
 
-    case COMMAND_REQUEST_AUTO_LDR: {
+    case COMMAND_REQUEST_AUTO_BRIGHT: {
         DynamicJsonDocument config(1024);
-        config["command"] = "autoLdr";
+        config["command"] = "autoBright";
         if (G.param1 == 0) {
-            config["autoLdrEnabled"] = G.autoLdrEnabled;
-            config["autoLdrBright"] = G.autoLdrBright;
-            config["autoLdrDark"] = G.autoLdrDark;
+            config["autoBrightEnabled"] = G.autoBrightEnabled;
+            config["autoBrightOffset"] = G.autoBrightOffset;
+            config["autoBrightSlope"] = G.autoBrightSlope;
         }
-        config["autoLdrValue"] = map(analogRead(A0), 0, 1023, 0, 255);
+        //Original: config["autoBrightSensor"] = map(analogRead(A0), 0, 1023, 0, 255);
+        config["autoBrightSensor"] = (int)lux;
+        config["autoBrightGain"] = (int)ledGain;
         serializeJson(config, str);
         webSocket.sendTXT(G.client_nr, str, strlen(str));
         break;
@@ -1154,7 +1197,7 @@ void ClockWork::loop(struct tm &tm) {
 
     case COMMAND_SET_MINUTE:
     case COMMAND_SET_BRIGHTNESS:
-    case COMMAND_SET_AUTO_LDR:
+    case COMMAND_SET_AUTO_BRIGHT:
     case COMMAND_SET_LANGUAGE_VARIANT:
     case COMMAND_SET_WHITETYPE:
     case COMMAND_SET_TIME_MANUAL: {

include/config.h

@@ -200,7 +200,7 @@
  *
  * Valid values [0 ... 255]
  */
-#define SERNR 33
+#define SERNR 58
 //--------------------------------------------------------------------------
 // Toggle Serial DEBUG Output
 //--------------------------------------------------------------------------

include/led.hpp

@@ -122,7 +122,7 @@ void Led::resetFrontMatrixBuffer() {
 
 float Led::setBrightnessAuto(float val) {
     // G.hh contains time-dependent brightness values in %.
-    return (val * ldrVal) / 100.f;
+    return (val * ledGain) / 100.f;
 }
 
 //------------------------------------------------------------------------------
@@ -156,7 +156,7 @@ void Led::getColorbyPositionWithAppliedBrightness(HsbColor &color,
     uint8_t manBrightnessSetting = 100;
     getCurrentManualBrightnessSetting(manBrightnessSetting);
 
-    if (G.autoLdrEnabled) {
+    if (G.autoBrightEnabled) {
         color.B = setBrightnessAuto(color.B);
     } else {
         color.B *= manBrightnessSetting / 100.f;

include/webPageAdapter.h

@@ -360,10 +360,10 @@ void webSocketEvent(uint8_t num, WStype_t type, uint8_t *payload,
 
             //------------------------------------------------------------------------------
 
-        case COMMAND_SET_AUTO_LDR: {
-            G.autoLdrEnabled = split(payload, 3);
-            G.autoLdrBright = split(payload, 6);
-            G.autoLdrDark = split(payload, 9);
+        case COMMAND_SET_AUTO_BRIGHT: {
+            G.autoBrightEnabled = split(payload, 3);
+            G.autoBrightOffset = split(payload, 6);
+            G.autoBrightSlope = split(payload, 9);
             break;
         }
 
@@ -561,7 +561,7 @@ void webSocketEvent(uint8_t num, WStype_t type, uint8_t *payload,
 
             //------------------------------------------------------------------------------
 
-        case COMMAND_REQUEST_AUTO_LDR: {
+        case COMMAND_REQUEST_AUTO_BRIGHT: {
 
             G.param1 = split(payload, 3);
             G.client_nr = num;

platformio.ini

@@ -26,4 +26,5 @@ lib_deps =
     adafruit/RTClib@^1.11.2
     knolleary/PubSubClient@^2.8.0
     https://github.com/tzapu/WiFiManager#v2.0.17
+    claws/BH1750@^1.3.0
 extra_scripts = pre:extra_scripts.py

src/Wortuhr.cpp

@@ -231,9 +231,9 @@ void setup() {
         G.bootShowWifi = true;
         G.bootShowIP = BOOT_SHOWIP;
 
-        G.autoLdrEnabled = 0;
-        G.autoLdrBright = 100;
-        G.autoLdrDark = 10;
+        G.autoBrightEnabled = 0;
+        G.autoBrightOffset = 100;
+        G.autoBrightSlope = 10;
         G.transitionType = 0; // Transition::NO_TRANSITION;
         G.transitionDuration = 2;
         G.transitionSpeed = 30;
@@ -433,7 +433,7 @@ void loop() {
     httpServer.handleClient();
 
     webSocket.loop();
-
+ 
     //------------------------------------------------
     // MQTT
     //------------------------------------------------

webpage/index.html

@@ -569,7 +569,7 @@ <h2 data-i18next="settings.manual-time.h2"></h2>
                     <h2 data-i18next="settings.brightness.h2"></h2>
                     <form class="pure-form pure-form-aligned">
                         <div class="pure-control-group">
-                            <label for="auto-ldr-enabled" data-i18next="settings.brightness.mode"></label><select id="auto-ldr-enabled" size="1">
+                            <label for="auto-bright-enabled" data-i18next="settings.brightness.mode"></label><select id="auto-bright-enabled" size="1">
                                 <option value="1" data-i18next="settings.brightness.automatic"></option>
                                 <option value="0" data-i18next="settings.brightness.manual"></option>
                             </select>
@@ -665,14 +665,17 @@ <h2 data-i18next="settings.brightness.h2"></h2>
                         <div class="specific-layout-brightness-auto">
                             <br>
                             <div class="pure-control-group">
-                                <label for="auto-ldr-value" data-i18next="settings.brightness.ldr-value"></label><input id="auto-ldr-value" type="text" value=" " readonly>
+                                <label for="auto-bright-sensor" data-i18next="settings.brightness.value-sensor"></label><input id="auto-bright-sensor" type="text" value=" " readonly>
+                                <label for="auto-bright-gain" data-i18next="settings.brightness.value-gain"></label><input id="auto-bright-gain" type="text" value=" " readonly>
                             </div>
                             <br>
+                            <legend data-i18next="settings.brightness.help-offset"></legend>
                             <div class="pure-control-group">
-                                <label for="auto-ldr-bright" data-i18next="settings.brightness.value-bright"></label><input id="auto-ldr-bright" type="number" min="0" max="255">
+                                <label for="auto-bright-offset" data-i18next="settings.brightness.value-offset"></label><input id="auto-bright-offset" type="number" min="0" max="255">
                             </div>
+                            <legend data-i18next="settings.brightness.help-slope"></legend>
                             <div class="pure-control-group">
-                                <label for="auto-ldr-dark" data-i18next="settings.brightness.value-dark"></label><input id="auto-ldr-dark" type="number" min="0" max="255">
+                                <label for="auto-bright-slope" data-i18next="settings.brightness.value-slope"></label><input id="auto-bright-slope" type="number" min="0" max="255">
                             </div>
                             <!-- Specific Brightness-automatic End-->
                         </div>

webpage/language/de.js

@@ -250,9 +250,14 @@ let TRANSLATION_DE_DE = {
 			"eighteen-to-twenty": "18:00 – 19:59",
 			"twenty-to-twenty-two": "20:00 – 21:59",
 			"twenty-two-to-zero": "22:00 – 23:59",
-			"ldr-value": "Aktuelle Helligkeit vom Fotowiderstand (LDR)",
-			"value-bright": "Wert „Hell“ (0 – 255)",
-			"value-dark": "Wert „Dunkel“ (0 – 255)"
+			"value-sensor": "Licht Sensor [Lux]",
+			"value-gain": "LED Gain [%]",
+			"help-offset": "Konfiguration des Helligkeitsoffsets: Sie bestimmt die minimale Helligkeit der LEDs bei 0 Lux Umgebungslicht:\n" +
+				"0=LEDs aus, n=LED Helligkeit ist n/255, 255=LEDs haben immer die maximale Helligkeit",
+			"value-offset": "Offset (0–255)",
+			"help-slope": "Konfiguration der Steilheit: Sie bestimmt den Grad der LED-Helligkeitsänderung bei Änderung des Umgebungslichts.\n" +
+				"0=schwache LED-Helligkeitsänderung, 16=neutrale LED-Helligkeitsänderung, 255=starke LED-Helligkeitsänderung",
+			"value-slope": "Steilheit (0–255)"
 		},
 		"hostname": {
 			"h2": "Hostname",

webpage/language/en.js

@@ -250,9 +250,9 @@ let TRANSLATION_EN_US = {
 			"eighteen-to-twenty": "18:00 – 19:59",
 			"twenty-to-twenty-two": "20:00 – 21:59",
 			"twenty-two-to-zero": "22:00 – 23:59",
-			"ldr-value": "Current Brightness from the Photoresistor (LDR)",
-			"value-bright": "Value “Bright” (0 – 255)",
-			"value-dark": "Value “Dark” (0 – 255)"
+			"value-sensor": "Current Brightness from the Photoresistor (LDR)",
+			"value-offset": "Value “Bright” (0 – 255)",
+			"value-slope": "Value “Dark” (0 – 255)"
 		},
 		"hostname": {
 			"h2": "Hostname",

webpage/language/es.js

@@ -223,9 +223,9 @@ let TRANSLATION_ES = {
 			"eighteen-to-twenty": "18:00 – 19:59",
 			"twenty-to-twenty-two": "20:00 – 21:59",
 			"twenty-two-to-zero": "22:00 – 23:59",
-			"ldr-value": "Brillo actual del fotorresistor (LDR)",
-			"value-bright": "Valor „Brillante“ (0 – 255)",
-			"value-dark": "Valor „Oscuro“ (0 – 255)"
+			"value-sensor": "Brillo actual del fotorresistor (LDR)",
+			"value-offset": "Valor „Brillante“ (0 – 255)",
+			"value-slope": "Valor „Oscuro“ (0 – 255)"
 		},
 		"hostname": {
 			"h2": "Hostname",