Week 13: Networking and Communications

Assignment

For this assignment the objective is to make two microcontroller communicate whether wireless or wire to each other.

I designed a board with ESP8266 chip and LED to communicate wireless with another copy of the same design.

From the same process as week 6 of designing a PCB in KiCAD, I designed the board was going to use by importing all components needed and aligning and connecting parts that supposed to connect.

I continued to design the board layout for making a PCB.

I aligned components and made an edge cut of the PCB.

When components are aligned correctly it is easy to create layouts.

This is a 3D view of the final board.

I moved to the next step of milling the board.

This is the final look of the board after being milled.

I soldered all the components in their place.

This is the list of components used for each board.

No	Component Name	Pieces
1	ESP8266 ESP-3	1
2	FTDI connector	1
3	LM1117-3.3	1
4	Tactile button	2
5	LED	1
6	Resistor	2
7	Capacitor	1

To program this board I used the arduino IDE and I had to add the board in the IDE. I did it using this guide. The library I used were include when I installed the board in the IDE.

Server side program.

#include <ESP8266WiFi.h>

WiFiServer server(80);    // Server Port
IPAddress ip(192,168,43,100);   // Fixed IP address for server
IPAddress gateway(192,168,43,1);    // Router's IP address
IPAddress subnet(255,255,255,0);

char ssid[] = "YourSSIDhere";
char pass[] = "YourPassWordHere";

int ledPin = 9;
int button = 10;

void setup() {
  Serial.begin(115200);

  WiFi.config(ip, gateway, subnet);
  WiFi.begin(ssid, pass);
  while(WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println();

  server.begin();
  Serial.println("Server Started");

  Serial.print("Server's IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println();

}

void loop() {
  // Check if a client has connected
  WiFiClient client = server.available();
  if (!client) {
    return;
  }

  // Wait until the client sends some data
  Serial.println("new client");
  while (!client.available()) {
    delay(1);
  }

  // Read the first line of the request
  String request = client.readStringUntil('\r');
  Serial.println(request);
  client.flush();

  // Match the request
  if (request.indexOf("/led-on") > 0)  {
    digitalWrite(ledPin, HIGH);
  }

  if (request.indexOf("/led-off") > 0)  {
    digitalWrite(ledPin, LOW);
  }

  // stop connection with client
  client.stop();
  Serial.println("Client disonnected");
  Serial.println("");
}

Client side program.

#include <ESP8266WiFi.h>

IPAddress server(192,168,43,100);     // Fixed IP address of the server
WiFiClient client;

char ssid[] = "YourSSIDhere";
char pass[] = "YourPassWordHere";

int ledPin = 9;
int button = 10;

int lastBtnState = 0;

void setup() {
  Serial.begin(115200);

  pinMode(ledPin, OUTPUT);
  pinMode(button, INPUT);

  WiFi.begin(ssid, pass);
  while(WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(500);
  }
  Serial.println();

}

void loop() {

  if (digitalRead(button) == HIGH) {
    if (lastBtnState == 0) {
      client.connect(server, 80);
      client.write("/led-off");
      lastBtnState = 1;
    }

    else {
      client.connect(server, 80);
      client.write("/led-on");
      lastBtnState = 0;
    }
  }
}

Here I tested the code

below it is the video of the project working

Conclusion

The purpose of the project was to communicate 2 boards so that each can turn on an LED on the other, they communicate through WiFi. I used ESP8266 chip which are WiFi enabled and works at low power like other microcontroller.

Files used to design and program the board can be found here.