expose sensor with remaining timer

include/devices.h

@@ -53,6 +53,8 @@ namespace Devices {
                 displayTimerMqtt->updateState(value);
             }
         }).withMin(0).withMax(90).withStep(5).restoreStateFromCommand().build();
+    Sensor* timerRemainingMqtt = Builder<Sensor>::instance(new Sensor("Timer remaining", "timer_remaining"))
+        .withUnitMeasure("min").withPrecision(0).build();
     Switch* timerMqtt = Builder<Switch>::instance(new Switch{"Timer", "timer",
             [](const char* msg) {
                 if (strcmp("ON", msg) == 0) {
@@ -101,6 +103,7 @@ namespace Devices {
         )
         .addSecondary(ledMqtt)
         .addSecondary(timerMqtt)
+        .addSecondary(timerRemainingMqtt)
         .addConfiguration(brightnessMqtt)
         .addConfiguration(hourFormatMqtt)
         .addConfiguration(displayTimerMqtt)
@@ -125,5 +128,8 @@ namespace Devices {
         Display::Brightness::brightnessChangedCallback = []{
             brightnessMqtt->updateState(Display::Brightness::current);
         };
+        Display::Timer::timerCallback = []{
+            timerRemainingMqtt->updateState(to_string(Display::Timer::current).c_str());
+        };
     }
 }

include/display.h

@@ -79,6 +79,8 @@ namespace Display {
 
     namespace Timer {
         int8 timer = 0, current = 0;
+        void (*timerCallback)();
+
         Task tDisplayTimer(SECONDS(10), 2, 
             []{
                 if (current >= 0) {
@@ -101,6 +103,7 @@ namespace Display {
                     tDisplayTimer.setIterations(TASK_FOREVER);
                     tDisplayTimer.restart();
                 }
+                if (timerCallback) timerCallback();
             }, &ts, false, nullptr,
             []{
                 tDisplayTimer.disable();