Add serverTime to response

README.md

@@ -2,13 +2,21 @@
 
 ## TODO
 
+### Server
+
 - [x] Use timeout for fetching departures
 - [x] Add basic auth
 - [x] Create Nix package
 - [x] Create container
-- [x] Write ESP8266 client
-- [ ] Make port configurable
 - [x] Transfer using JSON
 - [x] Correctly implement basic auth
-- [ ] Use unidecode to replace non-ascii stuff in the backend
+- [ ] Make port configurable
+- [ ] Use unidecode to replace non-ascii stuff
 - [ ] Add query parameter for selecting EFAClient
+- [ ] Return current time for displaying clock
+
+### Client
+
+- [x] Write ESP8266 client
+- [x] Add code for handling button presses
+- [ ] Add clock

client/client.ino

@@ -21,10 +21,10 @@
 #define FRAME_DELAY 80
 #define COLOR_BG (rgb(0, 0, 0))
 #define COLOR_DIVIDER (rgb(0xff, 0x60, 0x0d))
+#define COLOR_TOP (rgb(0xa0, 0xa0, 0xa0))
 #define COLOR_TEXT (rgb(0xff, 0x60, 0x0d))
 
 // Layout
-
 #define WIDTH 160
 #define HEIGHT 128
 
@@ -34,24 +34,48 @@
 #define MARGIN_LEFT 5
 #define MARGIN_RIGHT 5
 
+#define TOP_X MARGIN_LEFT
+#define TOP_Y 4
+#define TOP_WIDTH (WIDTH - 2 * MARGIN_LEFT)
+#define TOP_HEIGHT CY
+
 #define MAIN_X MARGIN_LEFT
-#define MAIN_Y 9
+#define MAIN_Y 19
 #define MAIN_WIDTH (WIDTH - 2 * MARGIN_LEFT)
 #define MAIN_HEIGHT (8 * CY)
 
 #define CLOCK_X MARGIN_LEFT
 #define CLOCK_Y 113
+#define CLOCK_WIDTH (5 * CX)
+#define CLOCK_HEIGHT CY
 
 #define STATUS_X 83
 #define STATUS_Y CLOCK_Y
 #define STATUS_WIDTH (12 * CX)
 #define STATUS_HEIGHT CY
 
-// Function definitions
+struct Timetable {
+  const char *label;
+  const char *path;
+};
 
+// Selectable timetables
+Timetable timetables[] = {
+  {"Johanneskirche, Bstg. 1", "/departures?stop_id=de:08311:30104&platform=1"},
+  {"Johanneskirche, Bstg. 2", "/departures?stop_id=de:08311:30104&platform=2"},
+  {"Blumenthalstr., Bstg. A", "/departures?stop_id=de:08221:1225&platform=A"},
+  {"Blumenthalstr., Bstg. B", "/departures?stop_id=de:08221:1225&platform=B"}
+};
+size_t selectedTimetable = 0;
+
+// Function definitions
 void drawLayout();
+void clearTop();
+void clearStatus();
+void clearMain();
+void clearClock();
 uint16_t rgb(uint16_t, uint16_t, uint16_t);
-String fetchDepartures();
+String fetchDepartures(String);
 
 // Peripherals
 
@@ -59,10 +83,40 @@ Adafruit_ST7735 display(TFT_CS, TFT_DC, TFT_RESET);
 
 // App state interface
 
+//           init                                                   
+//             │                                                    
+//             │                                                   
+//             │                                                    
+//             │      ┌───┐                                         
+//          ┌──▼──────▼┐  │                                         
+//          │Connecting│  │!connected                               
+//          └──┬───▲──┬┘  │                                         
+//             │   │  └───┘                                         
+//             │   │                                                
+//    connected│   │!connected                                      
+//             │   │                                                
+//             │   │                                                
+//             │   │                             ┌───┐              
+//          ┌──▼───┴─┐   timeout (3s)   ┌────────▼┐  │              
+//          │Fetching◄──────────────────┤Selecting│  │              
+//          └──┬───▲─┘                  └────▲───┬┘  │button pressed
+//             │   │                         │   └───┘              
+// got response│   │timeout (25s)            │                      
+//             │   │                         │                      
+//             │   │                         │                      
+//             │   │                         │button pressed        
+//        ┌────▼───┴─────────┐               │                      
+//        │Showing Departures│───────────────┘                      
+//        └──────────────────┘                                      
+
 class State {
 public:
-  virtual void enter() = 0;
-  virtual void tick() = 0;
+  // When the state is entered
+  virtual void enter();
+  // Called in the business loop
+  virtual void tick();
+  // Called when the button is pushed
+  virtual void button();
   virtual ~State() = default;
 };
 
@@ -75,7 +129,6 @@ public:
 class StateFetching : public State {
 public:
   void enter() override;
-  void tick() override;
 };
 
 class StateShowingDepartures : public State {
@@ -87,8 +140,24 @@ public:
   StateShowingDepartures(String&);
   void enter() override;
   void tick() override;
+  void button() override;
 };
 
+class StateSelecting : public State {
+private:
+  unsigned long entered;
+public:
+  void enter() override;
+  void tick() override;
+  void button() override;
+};
+
+// Empty default implementations
+
+void State::enter() {}
+void State::tick() {}
+void State::button() {}
+
 // App state implementation
 
 uint64_t currentTick = 0;
@@ -107,6 +176,7 @@ void StateConnecting::enter() {
 
   display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
   display.setCursor(STATUS_X, STATUS_Y);
+  display.setTextColor(COLOR_TEXT);
   display.printf("connecting");
 }
 
@@ -114,6 +184,7 @@ void StateConnecting::tick() {
   if (WiFi.status() != WL_CONNECTED) {
     display.fillRect(STATUS_X + 11 * CX, STATUS_Y, CX, CY, COLOR_BG);
     display.setCursor(STATUS_X + 11 * CX, STATUS_Y);
+    display.setTextColor(COLOR_TEXT);
     display.print("|/-\\"[currentTick % 4]);
     delay(125);
     return;
@@ -133,19 +204,16 @@ void StateFetching::enter() {
     setState<StateConnecting>();
     return;
   }
-
   display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
+  display.setTextColor(COLOR_TEXT);
   display.setCursor(STATUS_X, STATUS_Y);
   display.print("    fetching");
   
-  String departuresRaw = fetchDepartures();
+  String departuresRaw = fetchDepartures(timetables[selectedTimetable].path);
   
   setState<StateShowingDepartures>(departuresRaw);
 };
 
-void StateFetching::tick() {
-}
-
 StateShowingDepartures::StateShowingDepartures(String &departuresRaw) {
   deserializeJson(departures, departuresRaw);
 }
@@ -154,16 +222,26 @@ void StateShowingDepartures::enter() {
   Serial.println("Entering StateShowingDepartures");
   entered = millis();
 
-  display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
-  display.fillRect(MAIN_X, MAIN_Y, MAIN_WIDTH, MAIN_HEIGHT, COLOR_BG);
+  clearStatus();
+  clearMain();
 
+  // draw timetable
+  display.setTextColor(COLOR_TEXT);
   int line = 0;
   for (JsonVariant departure : departures["departures"].as<JsonArray>()) {
+    if (line > 8) {
+      break;
+    }
+    
+
+    char symbol[3] = {0};
+    char direction[16] = {0};
+
+    utf8ToCP437German(departure["symbol"].as<const char *>(), symbol, std::size(symbol));
+    utf8ToCP437German(departure["direction"].as<const char *>(), direction, std::size(direction));
+
     display.setCursor(MAIN_X, MAIN_Y + (CY + 3) * line);
-    display.printf("%2s %-15.15s ",
-      departure["symbol"].as<const char*>(),
-      departure["direction"].as<const char *>()
-    );
+    display.printf("%2s %-15.15s ", symbol, direction);
     if (departure["leaving"].as<String>().equals("sofort")) {
       int16_t x = display.getCursorX();
       int16_t y = display.getCursorY();
@@ -183,6 +261,36 @@ void StateShowingDepartures::tick() {
   }
 }
 
+void StateShowingDepartures::button() {
+  setState<StateSelecting>();
+}
+
+void StateSelecting::enter() {
+  Serial.println("Entering StateSelecting");
+  entered = millis();
+  
+  clearMain();
+  clearStatus();
+}
+
+void StateSelecting::tick() {
+  unsigned long elapsed = millis() - entered;
+  if (elapsed > 3000) {
+    setState<StateFetching>();
+  }
+}
+
+void StateSelecting::button() {
+  entered = millis();
+  selectedTimetable = (selectedTimetable + 1) % (sizeof timetables / sizeof timetables[0]);
+  clearTop();
+  display.setCursor(TOP_X, TOP_Y);
+  display.setTextColor(COLOR_TOP);
+  display.print(timetables[selectedTimetable].label);
+}
+
+// button ISR setup
+
 int buttonPushed = false;
 
 void ICACHE_RAM_ATTR onButtonFalling() {
@@ -195,13 +303,15 @@ void setup() {
   Serial.println("serial init");
   display.initR();
   display.setSPISpeed(40000000);
+  display.cp437(true);
   display.setRotation(3);
   Serial.println("display initialized");
   Serial.printf("display dimensions: %" PRId16 "x%" PRId16 "\n", display.width(), display.height());
 
-  display.setTextSize(1);
-  display.setTextColor(COLOR_TEXT);
   drawLayout();
+  display.setCursor(TOP_X, TOP_Y);
+  display.setTextColor(COLOR_TOP);
+  display.print(timetables[selectedTimetable].label);
 
   WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
   
@@ -211,13 +321,16 @@ void setup() {
   state = std::make_unique<StateConnecting>();
 }
 
-#define QUERY_STRING "stop_id=de:08221:1225&platform=A"
-
 void loop() {
   if (stateChanged) {
     stateChanged = false;
     // Note: enter() may call setState(). In that case we want to end up right back here.
     state->enter();
+  } else if (buttonPushed) {
+    // "Handle" jitter
+    delay(100);
+    buttonPushed = false;
+    state->button();
   } else {
     state->tick();
     currentTick++;
@@ -231,22 +344,36 @@ uint16_t rgb(uint16_t r, uint16_t g, uint16_t b) {
   return ((b >> 3) & 0b11111) << 11 | ((g >> 2) & 0b111111) << 5 | ((r >> 3) & 0b11111);
 }
 
+void clearTop() {
+  display.fillRect(TOP_X, TOP_Y, TOP_WIDTH, TOP_HEIGHT, COLOR_BG);
+}
+
+void clearMain() {
+  display.fillRect(MAIN_X, MAIN_Y, MAIN_WIDTH, MAIN_HEIGHT, COLOR_BG);
+}
+
+void clearStatus() {
+  display.fillRect(STATUS_X, STATUS_Y, STATUS_WIDTH, STATUS_HEIGHT, COLOR_BG);
+}
+
+void clearClock() {
+  display.fillRect(CLOCK_X, CLOCK_Y, CLOCK_WIDTH, CLOCK_HEIGHT, COLOR_BG);
+}
+
 void drawLayout() {
   display.fillScreen(COLOR_BG);
-  display.drawFastHLine(5, 4, 150, COLOR_DIVIDER);
+  display.drawFastHLine(5, 15, 150, COLOR_DIVIDER);
   display.drawFastHLine(5, 109, 150, COLOR_DIVIDER);
   display.drawFastHLine(5, 123, 150, COLOR_DIVIDER);
-  display.setCursor(CLOCK_X, CLOCK_Y);
-  display.print("13:12");
 }
 
 // TODO: Error handling
-String fetchDepartures() {
+String fetchDepartures(String path) {
   std::unique_ptr<BearSSL::WiFiClientSecure> https(new BearSSL::WiFiClientSecure);
   https->setInsecure();
   
   HTTPClient client;
-  if (!client.begin(*https, "vrnp.beany.club", 443, "/departures?" QUERY_STRING)) {
+  if (!client.begin(*https, "vrnp.beany.club", 443, path)) {
     display.fillScreen(COLOR_BG);
     display.setCursor(0, 0);
     display.print("begin failed");
@@ -265,3 +392,70 @@ String fetchDepartures() {
 
   return client.getString();
 }
+
+char mapUtf8CodepointToCP437German(uint32_t codepoint) {
+  switch (codepoint) {
+    case 0x00e4: return 0x84; // ä
+    case 0x00c4: return 0x8e; // Ä
+    case 0x00f6: return 0x94; // ö
+    case 0x00d6: return 0x99; // Ö
+    case 0x00fc: return 0x81; // ü
+    case 0x00dc: return 0x9a; // Ü
+    case 0x00df: return 0xe1; // ß
+    default: return '?';
+  }
+}
+
+/*
+Maps german umlauts and sharp s from utf8 to cp437 encoding.
+Other utf8 characters and malformed utf8 are replaced by '?'.
+The resulting string is truncated to cp437StrSize.
+*/
+void utf8ToCP437German(const char *utf8Str, char *cp437Str, size_t cp437StrSize) {
+  size_t utf8StrLength = strlen(utf8Str);
+  size_t utf8StrIndex = 0;
+  size_t cp437StrIndex = 0;
+
+  char c;
+
+  // One char at the end of the cp437Str is reserved to the terminating null
+  while (utf8StrIndex < utf8StrLength && cp437StrIndex + 1 < cp437StrSize) {
+    uint8_t cu0 = utf8Str[utf8StrIndex];
+
+    if (cu0 < 0x80) {
+      // ASCII maps to ASCII
+      c = cu0;
+      utf8StrIndex++;
+    } else if ((cu0 & 0b11100000) == 0b11000000) {
+      // codepoints encoded as two code units may contain german special characters
+      if (utf8StrIndex + 1 >= utf8StrLength) {
+        // if there's no 10xxxxxxx byte after this one, we've reached the end (malformed)
+        c = '?';
+        break;
+      } else {
+        // otherwise decode the codepoint and map it to cp437
+        uint8_t cu1 = utf8Str[utf8StrIndex + 1];
+        uint32_t cp = (cu0 & 0x1f << 6) | cu1 & 0x3f;
+        c = mapUtf8CodepointToCP437German(cp);
+        utf8StrIndex += 2;
+      }
+    // for 3 and 4-code unit codepoints just put a ? and skip all their code units
+    // here we dont care whether the string is malformed
+    } else if ((cu0 & 0b11110000) == 0b11100000) {
+      c = '?';
+      utf8StrIndex += 3;
+    } else if ((cu0 & 0b11111000) == 0b11110000) {
+      c = '?';
+      utf8StrIndex += 4;
+    } else {
+      // catch all for malformed utf8
+      c = '?';
+      utf8StrIndex++;
+    }
+
+    cp437Str[cp437StrIndex] = c;
+    cp437StrIndex++;
+  }
+
+  cp437Str[cp437StrIndex] = '\0';
+}

flake.nix

@@ -16,7 +16,7 @@
 
       vrnp-static = pkgs.buildGoModule {
         pname = "vrnp";
-        version = "0.0.9";
+        version = "0.0.10";
         vendorHash = null;
 
         # For building the package, we use only the files not ignored by Git as inputs.

main.go

@@ -17,6 +17,7 @@ import "time"
 // JSON unmarshaling types for departure monitor API
 
 type DMResponse struct {
+	DateTime DMDateTime `json:"dateTime"`
 	DepartureList []DMDeparture `json:"departureList"`
 }
 
@@ -213,6 +214,7 @@ func FetchDepartures(c EFAClient, stopId string) (DMResponse, error) {
 
 type Departures struct {
 	Departures []Departure `json:"departures"`
+	ServerTime string      `json:"serverTime"`
 }
 
 type Departure struct {
@@ -273,7 +275,12 @@ func ParseDepartures(response DMResponse, allowedPlatform *string) (Departures,
 		return cmp.Compare(a.Countdown, b.Countdown)
 	})
 
-	return Departures{ds}, nil
+	dt := response.DateTime
+
+	return Departures{
+		ds,
+		fmt.Sprintf("%02s:%02s", dt.Hour, dt.Minute),
+	}, nil
 }
 
 func main() {