ESP32-LCD

esp32-lcd/README.md

@@ -0,0 +1,52 @@
+# ESP32-LCD
+
+A status LCD for your homelab.
+
+![ESP32-LCD prototype](../images/esp32-lcd.jpg)
+
+## BOM
+
+- Any HD44780-based character LCD display, up to 20x4 characters. The most common are 16x2 characters (16 characters per row, 2 rows).
+- An ESP-32 board
+- A potentiometer, usually a 10 or 100k one, for controlling contrast (a couple of resistances arranged as a voltage divider may also be fine)
+
+## Assembly
+
+Connect the LCD to the board:
+
+LCD Pin		ESP32 Pin
+____________________________________
+PIN01-VSS	GND
+PIN02-VDD	5V
+PIN03 V0	10K Pot (Middle pin)
+PIN04 RS	GPIO19
+PIN05 RW	GND
+PIN06  E	GPIO23
+PIN07 D0	NOT USED
+PIN08 D1	NOT USED
+PIN09 D2	NOT USED
+PIN10 D3	NOT USED
+PIN11 D4	GPIO18
+PIN12 D5	GPIO17
+PIN13 D6	GPIO16
+PIN14 D7	GPIO15
+PIN15 A		5V
+PIN16 K		GND
+
+Open config.h file and set display size and your wifi data.
+
+Flash the code to the ESP32. If you use the Arduino ide to do it, just open the esp32-lcd.ino file with the Arduino ide and follow [this instructions](https://randomnerdtutorials.com/getting-started-with-esp32/)
+
+Restart the ESP32. The display shows "Conn to wifi..." with the WIFI name in the second line (if using a two or more lines display) and then will show the IP address.
+
+## Use
+
+- Turn on the circuit, wait for connection and note down the IP address shown on the screen.
+- Make a GET request to the same IP address with a parameter "message" containing some text
+
+> Example: to make the request using CURL from command line, try something along this lines (replace the IP addr with the one shown in the display):
+> curl -G http://192.168.1.78 --data-urlencode "message=Something interesting happened!"
+
+## Troubleshooting
+
+The ESP32 logs are written in the serial monitor at 115200 baud. Just open the Arduino ide Serial Monitor from Tools menu and look at the logs.

esp32-lcd/esp32-lcd/.gitignore

@@ -0,0 +1,2 @@
+config.h
+

esp32-lcd/esp32-lcd/config.h.example

@@ -0,0 +1,15 @@
+/**
+	CONFIGURATION FILE
+	Change the values in this file and rename it "config.h" before uploading the code to the board.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+const char* WIFI_SSID = "Squicky";
+const char* WIFI_PASSWORD = "SediaChinita@Terrazzo2017";
+const unsigned int DISPLAY_WIDTH = 16;
+const unsigned int DISPLAY_HEIGHT = 2;
+
+#endif
+

esp32-lcd/esp32-lcd/esp32-lcd.ino

@@ -3,9 +3,12 @@
 #include <WebServer.h>
 #include <ESPmDNS.h>
 #include <LiquidCrystal.h>
+#include "config.h"
 
-const char* ssid = "ichibi";
-const char* password = "uffobaruffo";
+// ------- Configuration is in config.h file -------
+
+const int WEBSERVER_PORT = 80;
+const char* WEBSERVER_MESSAGE_PARAM = "message";
 
 /*
  
@@ -30,19 +33,25 @@ LCD Pin –>ESP32 Pins
 
  */
 
-WebServer server(80);
-
-// Init lcd
+WebServer server(WEBSERVER_PORT); // Server on port 80
 LiquidCrystal lcd(19, 23, 18, 17, 16, 15);
-
 const int led = 13;
 
+void lcdPrintMultilineMessage(String message) {
+  lcd.clear();
+  int startFrom = 0;
+  for (int i=0; i<DISPLAY_HEIGHT; i++) {
+    lcd.setCursor(0,i);
+    lcd.print(
+      message.substring(startFrom, startFrom + DISPLAY_WIDTH)
+    );
+    startFrom += DISPLAY_WIDTH;
+  }
+}
+
 void handleRoot() {
   digitalWrite(led, 1);
-  lcd.clear();
-  for (uint8_t i = 0; i < server.args(); i++) {
-    lcd.print(server.arg(i));
-  }
+  lcdPrintMultilineMessage(server.arg(WEBSERVER_MESSAGE_PARAM));
   server.send(200, "text/plain", "ok");
   digitalWrite(led, 0);
 }
@@ -65,18 +74,25 @@ void handleNotFound() {
 }
 
 void setup(void) {
-  // set up the LCD's number of columns and rows:
-  lcd.begin(16, 2);
-  // Print a message to the LCD.
-  lcd.print("Connecting to wifi...");
+  // LCD: set up
+  lcd.begin(DISPLAY_WIDTH, DISPLAY_HEIGHT);
 
-  // Init
+  // SERIAL: set up
+  Serial.begin(115200);
+  Serial.println("");
+
+  // STATUS LED: set up
   pinMode(led, OUTPUT);
   digitalWrite(led, 0);
-  Serial.begin(115200);
+  
+  // LCD: Show SSID
+  lcd.print("Conn to wifi...");
+  lcd.setCursor(0,1);
+  lcd.print(WIFI_SSID);
+
+  // Connect to wifi
   WiFi.mode(WIFI_STA);
-  WiFi.begin(ssid, password);
-  Serial.println("");
+  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
 
   // Wait for connection
   while (WiFi.status() != WL_CONNECTED) {
@@ -85,12 +101,14 @@ void setup(void) {
   }
   Serial.println("");
   Serial.print("Connected to ");
-  Serial.println(ssid);
+  Serial.println(WIFI_SSID);
   Serial.print("IP address: ");
   Serial.println(WiFi.localIP());
 
-  // Print to LCD
+  // Print IP addr to LCD
   lcd.clear();
+  lcd.print("Connected! IP:");
+  lcd.setCursor(0,1);
   lcd.print(WiFi.localIP());
 
   if (MDNS.begin("esp32")) {
@@ -108,13 +126,4 @@ void setup(void) {
 void loop(void) {
   server.handleClient();
   delay(2);//allow the cpu to switch to other tasks
-
-
-
-  
-  // set the cursor to column 0, line 1
-  // (note: line 1 is the second row, since counting begins with 0):
-  lcd.setCursor(0, 1);
-  // print the number of seconds since reset:
-  lcd.print(millis() / 1000);
 }