Implement basic character lcd support

main/lcd.cpp

 #include "lcd.h"
 #include "mqtt.h"
 
+#include <vector>
+#include <sstream>
+
 #include "Arduino.h"
 #include "LiquidCrystal.h"
 
-const uint8_t rs = 22, en = 23, d4 = 5, d5 = 18, d6 = 19, d7 = 21;
-LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
+LiquidCrystal lcd(-1, -1, -1, -1, -1, -1);
+
+void enable_lcd(const std::string& topic, uint8_t rs, uint8_t en, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7) {
+    lcd = LiquidCrystal(rs, en, d4, d5, d6, d7);
 
-void add_lcd(const std::string& topic) {
     lcd.begin(16, 2);
+    lcd.clear();
+    lcd.print("qthing");
+    lcd.setCursor(0, 1);
+    lcd.print("Hello World!");
 
     add_message_callback(topic, [](std::string message) {
         lcd.clear();
+        std::istringstream stream(message);
+        std::string line;
+
+        std::getline(stream, line);
         lcd.setCursor(0,0);
-        lcd.print(message.c_str());
-        lcd.setCursor(0,1);
-        lcd.print(message.c_str());
+        lcd.print(line.c_str());
+
+        if (std::getline(stream, line)) {
+            lcd.setCursor(0,1);
+            lcd.print(line.c_str());
+        }
     });
 }

main/lcd.h

 #ifndef LCD_H
 #define LCD_H
 
-#include <string>
-
-void add_lcd(const std::string& topic);
-
-#endif
\ No newline at end of file
+#endif

main/qthing.h

@@ -55,6 +55,8 @@ void add_button(gpio_num_t gpio, std::function<void()> on_press = NULL, std::fun
 void add_button(gpio_num_t gpio, std::string topic, std::string message);
 void add_relay(const std::string& topic, gpio_num_t gpio_off, gpio_num_t gpio_on);
 
+void enable_lcd(const std::string& topic, uint8_t rs, uint8_t en, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7);
+
 // event handler
 void add_wlan_connection_status_handler(connection_status_callback_t handler);
 void add_mqtt_connection_status_handler(connection_status_callback_t handler);