Screensaver to black out screen and save battery

.gitignore

@@ -5,3 +5,6 @@ platformio.ini
 lib/readme.txt
 .clang_complete
 .gcc-flags.json
+.vscode/.browse.c_cpp.db*
+.vscode/c_cpp_properties.json
+.vscode/launch.json

src/outset.cpp

@@ -148,8 +148,12 @@ void Outset::keypadEvent() {
   switch (currentState) {
     case TEXT_HISTORY_STATE: {
       char key = keypad.getKey();
-      if (key && key == '{') {
-        switchToState(TEXT_MESSAGE_STATE, CONFIRM);
+      if (key) {
+        lastWakeupEventMills = millis();
+        digitalWrite(TFT_PWR_EN, LOW); // on
+        if (key == '{') {
+          switchToState(TEXT_MESSAGE_STATE, CONFIRM);
+        }
       }
       break;
     }
@@ -170,6 +174,8 @@ void Outset::keypadEvent() {
 
       // Scan for keys and draw them on the screen
       if (keypad.getKeys()) {
+        lastWakeupEventMills = millis();
+        digitalWrite(TFT_PWR_EN, LOW); // on
         for (uint8_t i = 0; i < LIST_MAX; i++) {
           if (keypad.key[i].stateChanged) {
             switch (keypad.key[i].kstate) {
@@ -407,6 +413,8 @@ void Outset::blinkTextCursor(uint8_t x, uint8_t y) {
 }
 
 void Outset::textHistoryState(uint8_t event) {
+  lastWakeupEventMills = millis();
+  digitalWrite(TFT_PWR_EN, LOW); // on
   drawHeader(currentState);
   if (textHistory[0].isEmpty()) {
     tft.setCursor(24, 60);
@@ -415,11 +423,15 @@ void Outset::textHistoryState(uint8_t event) {
   else {
     drawTextHistory();
   }
-
   while (nextState == TEXT_HISTORY_STATE) {
+    if (millis() > (lastWakeupEventMills + SCREEN_SAVER_TIMEOUT)) {
+      digitalWrite(TFT_PWR_EN, HIGH); // off
+    }
     keypadEvent();
     listenForIncomingMessages();
     if (textHistoryNeedsUpdate) {
+      lastWakeupEventMills = millis();
+      digitalWrite(TFT_PWR_EN, LOW); // on
       drawTextHistory();
       textHistoryNeedsUpdate = false;
     }

src/outset.h

@@ -75,6 +75,9 @@ class Outset {
     // The state of the sym key on the keypad. Returns true if pressed else false
     bool symPressed;
 
+    // Last time a keypress or other event (i.e. new incoming data) happens in order to wake up screen
+   unsigned long lastWakeupEventMills;
+
     // Used for keeping the debounce state of the trackpad
     uint8_t trackpadState;
     uint8_t lastTrackpadState;

src/states.h

@@ -28,4 +28,6 @@
 // #define DEVICE_ID ?
 #define RF95_FREQ 915.0
 
+#define SCREEN_SAVER_TIMEOUT 5000
+
 #endif