simpleSA/simpleSA_wifi.cpp

/*
 *	"TinySA_wifi.cpp"
 *
 *	Trial wifi charting functionality to see if WiFi affects the scan results
 *	Based on example here https://circuits4you.com/2019/01/11/esp8266-data-logging-with-real-time-graphs/
 *
 *	Requires some files to be placed into the spiffs area of flash
 *
 *	Modified in Version 2.1 by WA2FZW:
 *
 *		Eliminated all calls to "WriteSettings". All of the functions in "Cmd.cpp"
 *		that actually update the "setting" structure elements now handle that task
 *		and do so based on whether or not the value of the parameter actually
 *		changed or not which wasn't the case before.
 */


#include "TinySA_wifi.h"				// WiFi definitions
#include "Si4432.h"						// Si4432 definitions
#include "Cmd.h"						// Command processing functions

extern	int	 	bpfCount;				// Number of elements in the bandpassFilters array
extern	int		updateSidebar;		// Flag to indicate no of clients has changed
extern	void 	ClearDisplay ();
extern	void	DisplayError ( uint8_t severity, const char *l1, const char *l2, const char *l3, const char *l4 );


/*
 *	In Version 1.8, the transmitter and receiver Si4432 modules are implemented as
 *	objects. 
 */

extern	Si4432	rcvr;					// Object for the receiver
extern	Si4432	xmit;					// And the transmitter

extern	bool	AGC_On;					// Flag indicates if Preamp AGC is enabled
extern	uint8_t	AGC_Reg;				// Fixed value for preampGain if not auto

extern uint32_t startFreq_IF;
extern uint32_t stopFreq_IF;
extern uint32_t sigFreq_IF;


AsyncWebServer server ( 80 );			// Create the webserver object
AsyncResponseStream *response;


/*
 *	Install WebSockets library by Markus Sattler
 *	https://github.com/Links2004/arduinoWebSockets
 */

WebSocketsServer webSocket = WebSocketsServer ( 81 );

uint8_t			socketNumber;
unsigned long	messageNumber;

extern uint8_t  numberOfWebsocketClients;

/*
 *	Tracking of number of Wi-Fi reconnects and total connection time
 */

unsigned long numberOfReconnects;
unsigned long millisConnected;

IPAddress ipAddress;				// Store the IP address for use elsewhere, eg info


/*
 *	Function to format IP address nicely
 */

char *FormatIPAddress ( IPAddress ipAddress )
{
	static char formatBuffer[20] = {0};
	sprintf( formatBuffer, "%d.%d.%d.%d", ipAddress[0], ipAddress[1],
										  ipAddress[2], ipAddress[3] );
	return formatBuffer;  
}


boolean startAP ()				// Start the WiFi Access Point, keep the user informed.
{
	ClearDisplay ();			// Fade to black

	Serial.println ( "Starting Access Point" );		// Put in the instructions


/*
 *	Start by kicking off the soft-AP.  Call depends on whether or not password
 *	is required to connect
 */

#ifdef AP_PASSWORD

	boolean result = WiFi.softAP ( PROGRAM_NAME, AP_PASSWORD );

#else

	boolean result = WiFi.softAP ( PROGRAM_NAME );

#endif  

	if ( !result )								// This has failed, tell the user
		DisplayError ( ERR_WARN, "Failed to open AP:", "WiFi Disabled", NULL, NULL );

	else
		ipAddress = WiFi.localIP ();

  	Serial.printf ( "Access Point started, result = %b \n", result );
	return result;					
}


boolean connectWiFi()				// Connect to Wifi using SSID (ie via Router)  
{

	Serial.printf ( "Connecting to: %s \n", WIFI_SSID );
//	Serial.println( (char *) &configuration.WiFi_SSID[0] );

	WiFi.softAPdisconnect ();		// Disconnect anything that we may have


/*
 *	Start the connection:
 */

//	WiFi.begin ( (char *) &configuration.WiFi_SSID[0], (char *) &configuration.WiFi_Password[0] );
	WiFi.begin ( WIFI_SSID, WIFI_PASSWORD );

	WiFi.setSleep  (false );			// Disable sleep


/*
 *	Apply any hostname that we may have
 */

//	if ( strlen ( (char *) &configuration.Hostname[0]) > 0 )
//		WiFi.setHostname ( (char *) &configuration.Hostname[0] );
//	else
		WiFi.setHostname ( PROGRAM_NAME );    

	int maxTry = 10;				// Wait for the connection to be made.

	tft.setCursor ( 0, 190 );
	tft.printf ( "Connecting to WiFi %s", WIFI_SSID );

	while (( WiFi.status() != WL_CONNECTED ) && ( maxTry > 0 ))
	{
		tft.print(".");					// Nice touch!!!
		delay ( 1000 );					// Wait and update the try count.
		maxTry--;

		if ( maxTry <= 0 )
		{
			DisplayError ( ERR_WARN, "Connecting to", WIFI_SSID, "failed!", "WiFi Disabled" );
			return false;
		}
	}

  
	ipAddress = WiFi.localIP ();				// We are connected, display the IP address

	Serial.printf ( "Connected - IP %s \n", FormatIPAddress ( ipAddress ));
	tft.printf ( "\n\nConnected - IP %s \n", FormatIPAddress ( ipAddress ));
}


/*
 *	Handle websocket events
 *  This is how dta is sent from the web page to the ESP32
 */

void webSocketEvent ( uint8_t num, WStype_t type, uint8_t* payload, size_t payloadLength )
{
	switch ( type )
	{
		case WStype_DISCONNECTED:
			Serial.printf("[%u] Disconnected!\n", num);
			if ( numberOfWebsocketClients > 0 ) 
				numberOfWebsocketClients--;
				updateSidebar = true;
			break;

		case WStype_CONNECTED:
			Serial.printf ( "[%u] Connected from ", num );
			Serial.println ( webSocket.remoteIP ( num ));
			numberOfWebsocketClients++;
			updateSidebar = true;
			webSocket.sendTXT ( num, "Connected" );		// send message back to client
			break;


/*
 *	Format of message to process
 *
 *		#a 123.123     Start frequency
 *		#b 123.123     Stop frequency
 *
 *	Other formats are ignored
 */

		case WStype_TEXT:
			if ( payload[0] == '#' )
			{
				if ( payloadLength > 3 )
				{
					char* field = strtok ( (char*) &payload[3], " " );	// Extract the field value as string
					float value = atof ( field );						// Convert to float

					if ( isnan ( value )) 								// If not a number
						return;											// Bail out!

					Serial.printf ( "payload command %c value %f\n", payload[1], value );

					switch ( payload[1] )
					{
						case 'a':
							SetSweepStart ( value * 1000000.0 );		// Set sweep start frequency
							break;

						case 'b':
							SetSweepStop ( value * 1000000.0 );			// Set sweep stop frequency
							break;

						case 'c':
							SetSweepCenter ( value * 1000000.0, WIDE );	// Set sweep center frequency
							break;

						case 'd':
							SetLoDrive ( (uint8_t) value );
							break;
 
						case 'g':
							SetPreampGain( (int) value );				// Set PreAmp gain register
							break;

						case 'i':										// IF Frequency
							SetIFFrequency ( (int32_t) ( value * 1000000.0 ));
							break;
 
 						case 'o':										// Ref Output (LO GPIO2)
							SetRefOutput ( (int) value ); 
							break;

						case 'p':										// Adjust actual power level      
							RequestSetPowerLevel( value );
							break;

						case 's':										// Adjust sweep span      
							SetSweepSpan ( (int32_t) ( value * 1000000.0 ));
							break;

						case 'A':										// Internal Attenuation (PE4302)      
							SetAttenuation ( value );
							break;

						case 'R':										// Requested RBW.  0=Auto
							SetRBW ( value );
							break;

						case 'S':										// Spur Reduction on/off
							SetSpur ( value );
							break;

						default:
							Serial.printf ( "payload[1] was %c\n", payload[1] );
							break;
					}
				}
			}

			else											// payload[0] is not '#'
			{
				webSocket.sendTXT ( num, "pong" );		// send message back to client to keep connection alive
				Serial.printf ( "[%u] get Text: %s\n", num, payload );
			}
			
			break;

		default:
			Serial.println ( "Case?" );
			break;
	}
}


/*
 *	Monitor Wi-Fi connection if it is alive. If not alive then wait until it reconnects.
 */

void isWiFiAlive ( void )
{
	if ( WiFi.status() != WL_CONNECTED )
	{
		Serial.print ( "not connected" );

		while ( WiFi.status() != WL_CONNECTED )
		{
			Serial.print ( "." );
			delay(500);
		}

		numberOfReconnects++;
		millisConnected = millis();
	}
}


/*
 *	Some routines for XML
 */

char *escapeXML ( char *s )					// Use special codes for some characters
{
	static char b[1024];

	b[0] = '\0';							// Null terminator

	for ( int i = 0; i < strlen(s); i++ )
	{
		switch  ( s[i] )
		{
			case '\"':
				strcat ( b,"&quot;" );
				break;   

			case '&':
				strcat (b, "&amp;" );
				break;   

			case '<':
				strcat ( b,"&lt;" );
				break;   

			case '>':
				strcat ( b,"&gt;" );
				break;   

			default:
				int l = strlen ( b );
				b[l] = s[i];
				b[l + 1] = '\0';
				break;
		}
	}
}


/*
 *	Add an XML tag with its value to the buffer b
 */
 
void addTagNameValue ( char *b, char *_name, char *value )
{
	strcat ( b,_name );
	strcat ( b, "=\"" );
	strcat ( b,value );
	strcat ( b,"\" " );      
}


/*
 *	On request from web page convert the data from a scan into XML and send
 *
 *	Ideally we would push the data to the web page at the end of a scan,
 *	or perhaps just create the xml at the end of each scan - investigate later
 */

void onGetScan ( AsyncWebServerRequest *request )
{
	response = request->beginResponseStream ( "text/xml" );
//	Serial.println ( "onGetScan" );

	response->print ( "<?xml version=\"1.0\" encoding=\"utf-16\"?>" );
	response->println ( "<Points>" );

	for( int i = 0; i < DISPLAY_POINTS-1; i++ )		// For each data point
	{
//		Serial.printf ( "<Point F=\"%i\" RSSI=\"%i\"/> %i\n",myFreq[i], myData[i], i );
		response->printf ( "<P F=\"%i\" R=\"%i\"/>\n", myFreq[i], myData[i] );
	}

	response->print ( "</Points>" );
	request->send ( response );
}


/*
 *	On request from web page convert the gain data from a sweep into JSON and send
 *	Ideally we would push the data to the web page at the end of a scan,
 */

void onGetGainSweep ( AsyncWebServerRequest *request )
{
	size_t bufferSize = JSON_ARRAY_SIZE ( DISPLAY_POINTS )
				+ JSON_OBJECT_SIZE ( 1 ) + DISPLAY_POINTS * JSON_OBJECT_SIZE ( 2 );

	AsyncJsonResponse * response = new AsyncJsonResponse ( false, bufferSize );
//	response->addHeader ( "Server","ESP Async Web Server" );

	JsonObject root = response->getRoot();
	JsonArray gainPoints = root.createNestedArray ( "gainPoints" );	// Add gainPoints array

/*
 *	Add the objects to the array
 */

	for ( int i = 0; i < DISPLAY_POINTS; i++ )		// For each data point
	{
		JsonObject dataPoint = gainPoints.createNestedObject();	// Add an object to the array
		dataPoint["x"] = myFreq[i]/1000000.0;		// set the x(frequency) value
		dataPoint["y"] = myGain[i];					// set the y (gain) value
	} 

	response->setLength();
	request->send ( response );
}


/*
 *	On request from web page convert the data from a sweep into JSON and send.
 *	Ideally we would push the data to the web page at the end of a scan.
 */

void onGetSweep ( AsyncWebServerRequest *request )
{
	size_t bufferSize = JSON_ARRAY_SIZE ( DISPLAY_POINTS )
					+ JSON_OBJECT_SIZE ( 14 ) + DISPLAY_POINTS * JSON_OBJECT_SIZE ( 2 );

	AsyncJsonResponse * response = new AsyncJsonResponse ( false, bufferSize );

	JsonObject root = response->getRoot();

	root["dispPoints"] = DISPLAY_POINTS;
	root["start"] = setting.ScanStart / 1000.0;
	root["stop"] = setting.ScanStop / 1000.0;
	root["IF"] = setting.IF_Freq / 1000000.0;
	root["attenuation"] = setting.Attenuate;   
	root["levelOffset"] = setting.LevelOffset;   
	root["setRBW"] = setting.Bandwidth10;   
	root["bandwidth"] = bandwidth;   
	root["RefOut"] = setting.ReferenceOut;   
	root["Drive"] = setting.Drive;
	root["sweepPoints"] = sweepPoints;

	if ( AGC_On )
		root["PreAmp"] = 0x60;  // Auto

	else
		root["PreAmp"] = setting.PreampGain;				// Fixed gain

	JsonArray Points = root.createNestedArray ( "Points" );	// Add Points array


	for ( int i = 0; i < DISPLAY_POINTS; i++ )      //For each data point
    {
		JsonObject dataPoint = Points.createNestedObject();  // add an object to the array
		dataPoint["x"] = myFreq[i]/1000000.0;   // set the x(frequency) value
		dataPoint["y"] = myData[i];             // set the y (RSSI) value
	}


	response->setLength();
	request->send ( response );
}


/*
 * On request from web page send the settings as JSON
 */
void onGetSettings (AsyncWebServerRequest *request)
{
	AsyncJsonResponse * response = new AsyncJsonResponse(false) ;

	JsonObject root = response->getRoot();

	root["mType"] = "Settings";
	root["dispPoints"] = DISPLAY_POINTS;
	root["start"] = setting.ScanStart / 1000.0;
	root["stop"] = setting.ScanStop / 1000.0;
	root["IF"] = setting.IF_Freq / 1000000.0;
	root["attenuation"] = setting.Attenuate;   
	root["levelOffset"] = setting.LevelOffset;   
	root["setRBW"] = setting.Bandwidth10;   
	root["bandwidth"] = bandwidth;   
	root["RefOut"] = setting.ReferenceOut;   
	root["Drive"] = setting.Drive;
	root["sweepPoints"] = sweepPoints;
	root["spur"] = setting.Spur;

	if ( AGC_On )
		root["PreAmp"] = 0x60;  // Auto

	else
		root["PreAmp"] = setting.PreampGain;  // Fixed gain
  
	response->setLength();
	request->send ( response );
//	Serial.printf ( "Get Settings sweepPoints %u\n", sweepPoints );
}


/*
 * Push the settings data to the websocket clients
 */
void pushSettings ()
{
size_t capacity = JSON_ARRAY_SIZE ( DISPLAY_POINTS )
				+ DISPLAY_POINTS*JSON_OBJECT_SIZE ( 2 ) + JSON_OBJECT_SIZE ( 13 );
static DynamicJsonDocument jsonDocument ( capacity );	// buffer for json data to be pushed to the web clients

	jsonDocument["mType"] = "Settings";
	jsonDocument["dispPoints"] = DISPLAY_POINTS;
	jsonDocument["start"] = setting.ScanStart / 1000.0;
	jsonDocument["stop"] = setting.ScanStop / 1000.0;
	jsonDocument["IF"] = setting.IF_Freq / 1000000.0;
	jsonDocument["attenuation"] = setting.Attenuate;   
	jsonDocument["levelOffset"] = setting.LevelOffset;   
	jsonDocument["setRBW"] = setting.Bandwidth10;   
	jsonDocument["bandwidth"] = bandwidth;   
	jsonDocument["RefOut"] = setting.ReferenceOut;   
	jsonDocument["Drive"] = setting.Drive;
	jsonDocument["sweepPoints"] = sweepPoints;
	jsonDocument["spur"] = setting.Spur;

	if ( AGC_On )
		jsonDocument["PreAmp"] = 0x60;					// Auto

	else
		jsonDocument["PreAmp"] = setting.PreampGain;	// Fixed gain

	String wsBuffer;

	if ( wsBuffer )
	{
		serializeJson ( jsonDocument, wsBuffer );
		webSocket.broadcastTXT ( wsBuffer );			//  Send to all connected websocket clients
	}

	else
		Serial.println ( "No buffer :(");

//	Serial.printf ( "Push Settings sweepPoints %u\n", sweepPoints );
}


/*
 * Push the settings data to the websocket clients
 */
void pushIFSweepSettings ()
{
size_t capacity = JSON_ARRAY_SIZE ( DISPLAY_POINTS )
				+ DISPLAY_POINTS*JSON_OBJECT_SIZE ( 2 ) + JSON_OBJECT_SIZE ( 13 );
static DynamicJsonDocument jsonDocument ( capacity );	// buffer for json data to be pushed to the web clients

	jsonDocument["mType"] = "Settings";
	jsonDocument["dispPoints"] = DISPLAY_POINTS;
	jsonDocument["start"] = startFreq_IF / 1000.0;
	jsonDocument["stop"] = stopFreq_IF / 1000.0;
	jsonDocument["IF"] = sigFreq_IF / 1000000.0;
	jsonDocument["attenuation"] = setting.Attenuate;   
	jsonDocument["levelOffset"] = setting.LevelOffset;   
	jsonDocument["setRBW"] = setting.Bandwidth10;   
	jsonDocument["bandwidth"] = bandwidth;   
	jsonDocument["RefOut"] = setting.ReferenceOut;   
	jsonDocument["Drive"] = setting.Drive;
	jsonDocument["sweepPoints"] = sweepPoints;
	jsonDocument["spur"] = setting.Spur;

	if ( AGC_On )
		jsonDocument["PreAmp"] = 0x60;					// Auto

	else
		jsonDocument["PreAmp"] = setting.PreampGain;	// Fixed gain

	String wsBuffer;

	if ( wsBuffer )
	{
		serializeJson ( jsonDocument, wsBuffer );
		webSocket.broadcastTXT ( wsBuffer );			//  Send to all connected websocket clients
	}

	else
		Serial.println ( "No buffer :(");

//	Serial.printf ( "Push Settings sweepPoints %u\n", sweepPoints );
}

/*
 * Push the settings data to the websocket clients
 */
void pushBandscopeSettings ()
{
size_t capacity = JSON_ARRAY_SIZE ( DISPLAY_POINTS )
				+ DISPLAY_POINTS*JSON_OBJECT_SIZE ( 2 ) + JSON_OBJECT_SIZE ( 13 );
static DynamicJsonDocument jsonDocument ( capacity );	// buffer for json data to be pushed to the web clients

	jsonDocument["mType"] = "Settings";
	jsonDocument["dispPoints"] = setting.BandscopePoints;
	jsonDocument["start"] = setting.BandscopeStart / 1000.0;
	jsonDocument["stop"] = ( setting.BandscopeStart + setting.BandscopeSpan ) / 1000.0;
	jsonDocument["IF"] = setting.IF_Freq / 1000000.0;
	jsonDocument["attenuation"] = setting.Attenuate;   
	jsonDocument["levelOffset"] = setting.LevelOffset;   
	jsonDocument["setRBW"] = setting.Bandwidth10;   
	jsonDocument["bandwidth"] = bandwidth;   
	jsonDocument["RefOut"] = setting.ReferenceOut;   
	jsonDocument["Drive"] = setting.Drive;
	jsonDocument["sweepPoints"] = sweepPoints;
	jsonDocument["spur"] = setting.Spur;

	if ( AGC_On )
		jsonDocument["PreAmp"] = 0x60;					// Auto

	else
		jsonDocument["PreAmp"] = setting.PreampGain;	// Fixed gain

	String wsBuffer;

	if ( wsBuffer )
	{
		serializeJson ( jsonDocument, wsBuffer );
		webSocket.broadcastTXT ( wsBuffer );			//  Send to all connected websocket clients
	}

	else
		Serial.println ( "No buffer :(");

//	Serial.printf ( "Push Settings sweepPoints %u\n", sweepPoints );
}

/*
 * Prepare a response ready for push to web clients
 */

/*
 *	On request from web page return the list of valid RBW settings from the
 *	"bandpassFilters" array (found in the ".ino" file).
 */

void onGetRbwList ( AsyncWebServerRequest *request )
{
	response = request->beginResponseStream ( "application/json" );
//  Serial.println ( "onGetRbwList" );

	response->print ( "[" );          // Start of object

	int filterCount = rcvr.GetBandpassFilterCount (); 

	for ( int i = 0; i < filterCount-1 ; i++ )  // For each element in the bandpassfilters array
		response->printf ( "{\"bw10\":%i,\"bw\":%5.1f},",
					rcvr.GetBandpassFilter10(i),
					(float) rcvr.GetBandpassFilter10(i) / 10.0 );

	response->printf ( "{\"bw10\":%i,\"bw\":%5.1f}", rcvr.GetBandpassFilter10(filterCount-1),
					(float) rcvr.GetBandpassFilter10(filterCount-1) / 10.0 );
  
	response->println ( "]" );          // End of object
	request->send ( response );
}


/*
 *	On request from web page return the list of valid attenuations
 *	In the case of the PE4302 this is 0-31.5 in 0.5db steps, 
 *	but we will reduce this to 3dB steps
 *	Insertion loss is about 1.5dB
 *
 */

void onGetAttenList ( AsyncWebServerRequest *request )
{
	response = request->beginResponseStream ( "application/json" );
//	Serial.println ( "onGetAttList" );

	response->print ( "[" );					// Start of object
  
	for ( int i = 0; i < 30 ; i = i + 3 )		// For each possible attenuation
		response->printf ( "{\"dB\":%i},", i );

	response->printf ( "{\"dB\":%i}", 30 );
	response->println ( "]" );				// End of object
	request->send ( response );
}



/*
 *	Functions to execute when the user presses buttons on the webpage
 */
 
void onDoReboot ( AsyncWebServerRequest *request )
{
	request->redirect ( "index.html" );		// Redirect to the index page
	ESP.restart ();
}


/*
 *	Function sets the sweep parameters based on the data in the form posted by the web page
 *  No longer used
 */

//	doSetSweep ? setStart = 10 & setStop = 20 & setExtGain = 0 & setRBW = 26

void onSetSweep ( AsyncWebServerRequest *request )
{
  
	Serial.print ( request->url ());			// Get the paramaters passed from the 
	Serial.print ( ":-" );						// web page, checking they exist

	if ( request->hasParam ( "setStart" ))
	{
		Serial.print ( "setStart;" );
		AsyncWebParameter* startInput = request->getParam ( "setStart" );
		SetSweepStart ( atof ( startInput->value().c_str()) * 1000000.0 );
	}
  
	if ( request->hasParam ( "setStop" ))
	{
		Serial.print ( "setStop;" );
		AsyncWebParameter* stopInput = request->getParam ( "setStop" );
		SetSweepStop( atof ( stopInput->value().c_str()) * 1000000.0 );
	}
  
	if ( request->hasParam ( "setExtGain" ))
	{
		Serial.print ( "setExtGain;" );
		AsyncWebParameter* extGainInput = request->getParam ( "setExtGain" );
//		Need to add function later
	}
  
	if ( request->hasParam ( "refOut" ))
	{
		Serial.print ( "refOut;" );
		AsyncWebParameter* setRefOut = request->getParam ( "setRefOut" );
		setting.ReferenceOut = atoi ( setRefOut->value().c_str() );
		xmit.SetPowerReference ( setting.ReferenceOut );
	}
  
	if ( request->hasParam ( "setAtten" ))
	{
		Serial.print ( "setAtten:" );
		AsyncWebParameter* setAtten = request->getParam ( "setAtten");
		SetAttenuation ( atoi ( setAtten->value().c_str() ));
		Serial.print ( atoi ( setAtten->value().c_str() ));
		Serial.print ( "; " );
	}
  
	if ( request->hasParam ( "setRBW" ))
	{
		Serial.print ( "setRBW ");
		AsyncWebParameter* rbwInput = request->getParam ( "setRBW" );
		SetRBW ( atoi ( rbwInput->value().c_str() ));
		Serial.printf ( "setting.bandwidth = %i, input = %i;", setting.Bandwidth10, atoi ( rbwInput->value().c_str() ));
	}

	Serial.println ();
	request->redirect ( "index.html" );		// redirect to the index page
}


/*
 *	Function sets the sweep parameters based on the data in the form posted by the web page
 *  No longer used
 */

//	doSetSweep ? setStart = 10  &setStop = 20 & setExtGain = 0 & setRBW = 26

void onSettings ( AsyncWebServerRequest *request )
{
	Serial.print ( request->url() );			// Get the paramaters passed from the web
	Serial.print ( ":-" );						// page, checking they exist

	if ( request->hasParam ( "setActPower" ))
	{
		Serial.print ( "setActPower;" );
		AsyncWebParameter* setLevelInput = request->getParam ( "setActPower" );
		SetPowerLevel ( atof ( setLevelInput->value().c_str()) );
	}

	Serial.println();
	request->redirect ( "index.html");		// Redirect to the index page
}


void onGetNameVersion ( AsyncWebServerRequest *request )
{
	AsyncResponseStream *response = request->beginResponseStream ( "text/xml" );

	response->printf ( "<?xml version=\"1.0\" encoding=\"utf-16\"?>" );
	response->printf ( "<IndexNameVersion " );

	response->printf ( "Name=\"%s\" ",PROGRAM_NAME );
	response->printf ( "Version=\"V%s\" ",PROGRAM_VERSION ); 
	response->printf ( "Copyright=\"PD0EK\"" );

	response->printf ( "/>" );

	request->send(response);
}


void onGetSIDDs ( AsyncWebServerRequest *request )
{
	char b[1024];
	b[0] = '\0';

	Serial.println ( "" );
	Serial.println ( "Scanning for SSIDs" );
  

/*
 *	We need to return a blob of XML containing the visible SSIDs
 */
	strcpy ( b, "<SSIDs>" );					// Start of XML

	int n = WiFi.scanComplete ();

	if ( n == -2 )
		WiFi.scanNetworks ( true );
	else if ( n )
	{
		for ( int i = 0; i < n; ++i )
		{
			strcat ( b,"<SSID Name = \"" );		// Add the SSID to the result
			strcat ( b, WiFi.SSID (i).c_str() );
			strcat ( b,"\" />" );
			Serial.println ( "... " + WiFi.SSID (i) );
		}
		WiFi.scanDelete ();
		if ( WiFi.scanComplete() == -2 )
			WiFi.scanNetworks ( true );
	}
	strcat ( b, "</SSIDs>" );					// Complete the XML
	request->send ( 200, "text/xml", b );		// Send it to the server
}


/*
 * Build the web server
 * the order here is important - put frequent ones at top of list to improve performance
 */
void buildServer ()					// We can now configure and start the server
{
	Serial.println ( "Building Server.." );
	server.reset ();											// Clear any existing settings and events
	server.on ( "/getSweep", HTTP_GET, onGetSweep );			// Set event to return sweep data as JSON array
	server.on ( "/getGainSweep", HTTP_GET, onGetGainSweep );	// Set event to return sweep gain data as JSON array
	server.on ( "/getSettings", HTTP_GET, onGetSettings );		// Set event to return settings data as JSON array
	server.on ( "/doSetSweep", HTTP_POST, onSetSweep );			// Set event to set sweep values received from client
	server.on ( "/doReboot", HTTP_GET, onDoReboot );			// Set event to reboot the ESP32
	server.on ( "/getNameVersion", HTTP_GET, onGetNameVersion );// Set event to return name and version
	server.on ( "/getScan", HTTP_GET, onGetScan );				// Set event to return sweep data as XML
	server.on ( "/getRbwList", HTTP_GET, onGetRbwList );		// Set event to return RBW options as JSON array
	server.on ( "/getAttenList", HTTP_GET, onGetAttenList );	// Set event to return attenuator options as JSON array
	server.on ( "/getSSIDs", HTTP_GET, onGetSIDDs );			// Set event to return list of SSID as XML
	server.on ( "/doSettings", HTTP_POST, onSettings );			// Set event to set setting values received from client

	server.serveStatic ( "/", SPIFFS, "/" ).setDefaultFile ( "index.html" );

	server.begin ();
}