PixelHub/PixelHub-Client/PixelHub-Client.ino

/*
 * Connecting to a WiFi network with WPA
 ************************************************
 * Originally adapted from https://www.arduino.cc/en/Tutorial/ConnectWithWPA
 * by Starbeamrainbowlabs
 */

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

#include "Utilities.h"

char ssid[] = "ZimWeaver";
char password[] = "***REMOVED***";

// The address that the PixelHub beacon is broadcasting on.
IPAddress beaconAddress(239, 62, 148, 30);
// The port number that the PixelHub beacon is broadcasting on.
unsigned int beaconPort = 5050;

// A UDP Client to allow us to recieve UDP datagrams.
WiFiUDP UdpClient;
// The size of the datagram buffer that is used to buffer incoming messages.
int datagramBufferSize = 256;

WiFiClient tcpClient;
char pixelHubServerIp[16];
int pixelHubPortNumber;

void setup()
{
	// Setup the serial connection
	Serial.begin(4800);
	
	Serial.println("Hello, world!");
	
	Serial.println("Beginning connection sequence.");
	Serial.print("Attempting to connect to ");
	Serial.print(ssid);
	Serial.print(" - ");
	
	WiFi.begin(ssid, password);
	
	while(WiFi.status() != WL_CONNECTED)
	{
		// Wait a second for the connection to be established
		delay(1000);
	}
	
	Serial.println("success!");
	
	printWiFiInfoLocal();
	findServer();
}


void loop()
{
	
}


// ~~~ WiFi Diagnostics ~~~ //

/// <summary>
/// Prints the local IP address to the serial connection.
/// </summary>
void printWiFiInfoLocal()
{
	Serial.print("IP Address: ");
	Serial.println(WiFi.localIP());
}

// ~~~ PixelHub auto discovery system ~~~ //

/// <summary>
/// Listens for PixelHub beacon pings in order to determine the location of the PixelHub server.
/// </summary>
/// <description>
/// Puts the details it finds into the `pixelHubServerIp` and `pixelHubPortNumber`
/// </description>
void findServer()
{
	Serial.print("Initialising PixelHub auto detection system - ");
	byte datagramBuffer[datagramBufferSize];
	memset(datagramBuffer, '\0', datagramBufferSize); // Prefill the buffer with zeros for protection later
	UdpClient.beginMulticast(WiFi.localIP(), beaconAddress, beaconPort);
	Serial.println("success!");

	Serial.println("Listening for PixelHub beacon pings.");
	while(true) {
		int datagramSize = UdpClient.parsePacket();
		if(!datagramSize) continue;
		
		Serial.print("Received datagram #");
		Serial.print(datagramSize);
		Serial.print(" bytes in size from ");
		Serial.print(UdpClient.remoteIP());
		Serial.print(":");
		Serial.print(UdpClient.remotePort());
		if(datagramSize > datagramBufferSize) {
			Serial.println(", but the message is larger than the datagram buffer size.");
			continue;
		}
		Serial.println(".");
		
		UdpClient.read(datagramBuffer, datagramSize);
		
		Serial.print("Content as hex: ");
		for(int i = 0; i < datagramSize; i++) {
			Serial.print(datagramBuffer[i], HEX);
			Serial.print(" ");
		}
		Serial.println();
		Serial.print("Raw content: ");
		Serial.write(datagramBuffer, datagramSize);
		Serial.println();

		Serial.print("Parsing datagram - ");

		// Parse the recieved message
		char* datagramStr = (char*)datagramBuffer;

		// Find the positions of the key characters
		//int atPos = getPosition(datagramStr, datagramSize, '@');
		//int colonPos = getPosition(datagramStr, datagramSize, ':');
		int atPos = findChar(datagramStr, '@');
		int colonPos = findChar(datagramStr, ':');
		
		char role[7];
		char portNumberText[7];
		memset(role, '\0', 7);
		memset(pixelHubServerIp, '\0', 16);
		memset(portNumberText, '\0', 7);
		
		strncpy(role, datagramStr, atPos);
		strncpy(pixelHubServerIp, datagramStr + atPos + 1, colonPos - atPos - 1);
		strncpy(portNumberText, datagramStr + colonPos + 1, datagramSize - colonPos - 1);
		
		Serial.println("complete.");
		
		Serial.print("atPos: "); Serial.println(atPos);
		Serial.print("colonPos: "); Serial.println(colonPos);
		
		Serial.print("Role: "); Serial.print(role); Serial.print(" ");
		Serial.print("Remote IP: "); Serial.print(serverIp); Serial.print(" ");
		Serial.print("Port number: "); Serial.print(portNumberText);
		Serial.println();
		
		// If the advertiser isn't playing the role of a server, then we're not interested
		if(role != "server") continue;

		pixelHubPortNumber = atoi(portNumberText);

		return;
	}
}