LCD i2c Hello World (untested)

ESP8266/platformio.ini

@@ -12,6 +12,8 @@
 platform = espressif8266
 board = esp12e
 framework = arduino
-lib_deps = knolleary/PubSubClient@^2.8
+lib_deps = 
+	knolleary/PubSubClient@^2.8
+	enjoyneering/LiquidCrystal_I2C@^1.2.4
 monitor_speed = 921600
-upload_speed = 921600
+upload_speed = 921600

ESP8266/src/main.cpp

@@ -1,6 +1,7 @@
 #include <ENC28J60lwIP.h>
 #include <ESP8266WiFi.h>
 #include <PubSubClient.h>
+#include <LiquidCrystal_I2C.h>
 
 #include <credentials.hpp>
 
@@ -11,6 +12,7 @@
 ENC28J60lwIP ethernet(16);
 WiFiClientSecure espClient;
 PubSubClient client(espClient);
+LiquidCrystal_I2C lcd(PCF8574A_ADDR_A21_A11_A01);
 
 void mqttCallback(char *topic, byte *payload, unsigned int length) {
     uint8_t message[256];
@@ -30,6 +32,10 @@ void mqttCallback(char *topic, byte *payload, unsigned int length) {
         } else {
             Serial.printf("Undefined payload value\n");
         }
+    } else if (!strcmp(topic, ROOT_TOPIC "/display/set")) {
+        lcd.clear();
+        lcd.setCursor(0, 0);
+        lcd.printf("%s", message);
     } else {
         // If topic is not recognized, exit without publishing to /get
         Serial.printf("Unrecognized topic %s\n", topic);
@@ -129,6 +135,7 @@ void setup() {
     pinMode(LED_BUILTIN, OUTPUT);
     Serial.begin(921600);
     Serial.println();
+    lcd.begin(16, 2);
     BearSSL::X509List *clientTrustedCA =
         new BearSSL::X509List(Credentials::ca_cert);
     BearSSL::X509List *clientCertList =