Interface and Application Programming
(honestly, it is rarely this smooth. Usually, the control is laggy, maybe because I'm using it as an access point and not solder the wire, so the current was not stable while still consuming a large amount of power?)
GPIO 4
In Week 9 I learned that the GPIO 4 on ESP32-CAM is the flashlight, this week, I created
a UI to control it, so I can potentially use my final project (clock) even in the bad lighting
condition.
UI
I followed this tutorial to create the button for the pin that I want, but I noticed Harvard wifi again doesn't work with the ESP32-CAM, so I followed this tutorial to set up the ESP32-CAM as an access point, so I can connect to it.
Programming
The programming was very straightforward, basically just modifying the pin26 in the example into
pin04, and also updating the text in the UI to Flashlight is On/Off.
/*********
Rui Santos
Complete project details at http://randomnerdtutorials.com
*********/
// Load Wi-Fi library
#include <WiFi.h>
// Replace with your network credentials
const char* ssid = "ESP32-Access-Point-Zhuoyue";
const char* password = "66666666";
// Set web server port number to 80
WiFiServer server(80);
// Variable to store the HTTP request
String header;
// Auxiliar variables to store the current output state
String output04State = "off";
// Assign output variables to GPIO pins
const int output04 = 4;
// // Current time
// unsigned long currentTime = millis();
// // Previous time
// unsigned long previousTime = 0;
// // Define timeout time in milliseconds (example: 2000ms = 2s)
// const long timeoutTime = 2000;
void setup() {
Serial.begin(115200);
// Initialize the output variables as outputs
pinMode(output04, OUTPUT);
// Set outputs to LOW
digitalWrite(output04, LOW);
// Connect to Wi-Fi network with SSID and password
Serial.print("Setting AP (Access Point)…");
// Remove the password parameter, if you want the AP (Access Point) to be open
WiFi.softAP(ssid, password);
IPAddress IP = WiFi.softAPIP();
Serial.print("AP IP address: ");
Serial.println(IP);
server.begin();
}
void loop(){
WiFiClient client = server.available(); // Listen for incoming clients
if (client) { // If a new client connects,
Serial.println("New Client."); // print a message out in the serial port
String currentLine = ""; // make a String to hold incoming data from the client
while (client.connected()) { // loop while the client's connected
if (client.available()) { // if there's bytes to read from the client,
char c = client.read(); // read a byte, then
Serial.write(c); // print it out the serial monitor
header += c;
if (c == '\n') { // if the byte is a newline character
// if the current line is blank, you got two newline characters in a row.
// that's the end of the client HTTP request, so send a response:
if (currentLine.length() == 0) {
// HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
// and a content-type so the client knows what's coming, then a blank line:
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println("Connection: close");
client.println();
// turns the GPIOs on and off
if (header.indexOf("GET /04/on") >= 0) {
Serial.println("GPIO 04 on");
output04State = "on";
digitalWrite(output04, HIGH);
} else if (header.indexOf("GET /04/off") >= 0) {
Serial.println("GPIO 04 off");
output04State = "off";
digitalWrite(output04, LOW);
}
// Display the HTML web page
client.println("<!DOCTYPE html><html>");
client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
client.println("<link rel=\"icon\" href=\"data:,\">");
// CSS to style the on/off buttons
// Feel free to change the background-color and font-size attributes to fit your preferences
client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
client.println(".button { background-color: #4CAF50; border: none; color: white; padding: 16px 40px;");
client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
client.println(".button2 {background-color: #555555;}</style></head>");
// Web Page Heading
client.println("<body><h1>ESP32 Web Server</h1>");
// Display current state, and ON/OFF buttons for GPIO 04
client.println("<p>Flashlight is " + output04State + "</p>");
// If the output04State is off, it displays the ON button
if (output04State=="off") {
client.println("<p><a href=\"/04/on\"><button class=\"button\">ON</button></a></p>");
} else {
client.println("<p><a href=\"/04/off\"><button class=\"button button2\">OFF</button></a></p>");
}
client.println("</body></html>");
// The HTTP response ends with another blank line
client.println();
// Break out of the while loop
break;
} else { // if you got a newline, then clear currentLine
currentLine = "";
}
} else if (c != '\r') { // if you got anything else but a carriage return character,
currentLine += c; // add it to the end of the currentLine
}
}
}
// Clear the header variable
header = "";
// Close the connection
client.stop();
Serial.println("Client disconnected.");
Serial.println("");
}
}