Evan Rust
Published © GPL3+

ESP8266 Light Level Monitor

Using an ESP8266 Thing Dev, write the current light levels to a local webpage.

BeginnerFull instructions provided1 hour2,495
ESP8266 Light Level Monitor

Things used in this project

Hardware components

SparkFun ESP8266 Thing - Dev Board
SparkFun ESP8266 Thing - Dev Board
×1
Resistor 10k ohm
Resistor 10k ohm
×1
Jumper wires (generic)
Jumper wires (generic)
×1

Software apps and online services

Arduino IDE
Arduino IDE

Story

Read more

Schematics

Schematic

Code

The Code

C/C++
Make sure to add your credentials.
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>

const char* ssid = "SSID";
const char* password = "PSSWD";

ESP8266WebServer server(80);

void handleRoot() {
  String msg = "<html><head><title>ESP8266 Light Levels</title></head>";
  msg += "<body>";
  msg += "<p>The light level is: ";
  msg += String(analogRead(A0))+"</p>";
  msg += "<meta http-equiv=\"refresh\" content=\"1\" />";
  msg += "</body></html>";
  server.send(200, "text/html", msg);
}

void handleNotFound(){
  String message = "File Not Found\n\n";
  message += "URI: ";
  message += server.uri();
  message += "\nMethod: ";
  message += (server.method() == HTTP_GET)?"GET":"POST";
  message += "\nArguments: ";
  message += server.args();
  message += "\n";
  for (uint8_t i=0; i<server.args(); i++){
    message += " " + server.argName(i) + ": " + server.arg(i) + "\n";
  }
  server.send(404, "text/plain", message);
}

void setup(void){
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  Serial.println("");

  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  if (MDNS.begin("esp8266")) {
    Serial.println("MDNS responder started");
  }

  server.on("/", handleRoot);

  server.onNotFound(handleNotFound);

  server.begin();
  Serial.println("HTTP server started");
}

void loop(void){
  server.handleClient();
}

Credits

Evan Rust

Evan Rust

122 projects • 1079 followers
IoT, web, and embedded systems enthusiast. Contact me for product reviews or custom project requests.

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