simpleSA/simpleSA.ino

/*
 *	"simpleSA.ino"
 *
 *	This is the main program file for the "TinySA for ESP32" (spectrum analyzer) 
 *	
 *
 *   Copyright (C) 2020  David Wilde (M0WID), John Price (WA2FZW)
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 *
 *	The starting point for this version is the "tinySA_touch05" software developed
 *	by David (M0WID). 
 *	That software was based on the original version for STM "Blue Pill" by Erik Kaashoek PD0EK.
 *	For more information on that version visit https://groups.io/g/HBTE/topics
 *	
 *	Glen VK3PE has designed a set of PCB - see http://www.carnut.info/tinySA/tinySA.html
 *	
 *	Erik has since gone on to produce a commecial version, google tinySA, and this software 
 *	has been renamed simpleSA to avoid confusion.
 *
 *	Modified by John Price (WA2FZW):
 *
 *		Version 1.0:
 *			Just add comments, try to figure out how it all works and move some stuff
 *			around for clarity!
 *
 *
 *		Version 1.1:
 *			Added the file "Si4432.h" which contains symbols for all the Si4432
 *			registers and some other things related to it's operation.
 *
 *			Added the files "PE4302.h" and "PE4302.cpp" which provide a class/object
 *			implementation of the attenuator handling. One can now use either the
 *			serial or parallel type modules connected directly to the processor
 *			or the parallel module interfaced via a PCF8574 GPIO expander chip as
 *			Glenn (VK3PE) did on his hardware implementation.
 *
 *			The value stored in "setting.attenuate" is now a positive number. Previously
 *			it was stored as a negative value and displayed as "Atten: -nn", which would
 *			imply a gain! The PE4302 library also range limits the attenuator setting
 *			to a value between 0dB and 31dB, which is the range of the PE4302.
 *
 *			Incorporated changes from David's Version 05 release. Those changes include
 *			eliminating the support for the Arduino and the addition of WiFi capability.
 *
 *			Added the file "Si4432.h" which contains symbols for all the Si4432
 *
 *
 *		Version 1.6:
 *			Added the file "Si4432.cpp" and moved all of the functions to handle the
 *			interface to the hardware out of here. *
 *
 *		Version 1.7:
 *			Moved all the global variables to the top of the file and moved the "setup"
 *			and "loop" functions to the top where they are customarily found.
 *
 *			Stripped the serial interface command handler out of the "loop" function and
 *			created the "CheckCommand" function; made a lot of changes to how that all
 *			works also.
 *
 *
 *		Version 1.8:
 *			Replaced the original code to handle the Si4432 modules with a class/object
 *			implementation using real SPI protocol.
 *
 *
 *		Version 2.0:
 *			Overhauled the serial command handler and help menu.
 *
 *
 *		Version 2.1:
 *			A major overhaul of the entire architecture! I moved all the functions that
 *			handle reading and processing commands from the serial input into "Cmd.cpp".
 *			This is the first step into being able to use common command processing for
 *			the serial interface, web page and touch screen.
 *
 *
 *		Version 2.7:
 *			More restructuring. Added markers . Added more
 *			commands to the serial command handler. Re-organized the touch screen menus
 *			in a more logical hierarchy and added some new capabilities there.
 *
 *
 *		Version 2.8 Changes by M0WID:
 *			Data now pushed to the web clients
 *			Grid y changed to have 10 divisions
 *			Various bug fixes
 *			Layout of display changed
 *			New Signal Generator mode
 *			Preparation for other modes eg High Frequency Range
 *			Scale for preamp gain trace added
 *			Spur Reduction now does something!
 *			
 *		Version 3.0a Changes by M0WID
 *			Variable no of points to push to WiFi clients to give more frequent updates at narrow RBW
 *			and fewer chart updates at wide RBW to reduce load on slow tablet or smartphone clients
 *			Only check for websockets at intervals or if client connected as websockets impose a significant time penalty
 *			Signal Generator menu and keypad frequency entry
 *			Calibrate of signal generator output added to menu
 *			Hot spots on touch to get to specific parts of the menu faster
 *			
 *		Version 3.0e Changes by M0WID	
 *			IF Sweep implemented to enable characterisation of the SAW filters, with its own menu
 *			LCD display no longer uses pin2 for reset - it is wired to the ESP32 reset instead, freeing up pin 2 for the tracking generator
 *			LCD display backlight no longer uses PWM to control the brightness, freeing up Pin 25 for the tracking generator.  
 *			You can uncomment the #define in my_SA.h if you still want the PWM backlight.
 *			Tracking generator options added, with either one or two additional SI4432.  If one SI4432 
 *				then the track generator LO is tapped off the existing LO and the track gen IF runs 
 *				at the same frequency as the receiver.  This can give reduced sensitivity.
 *				If two SI4432 are implemented then the tracking generator IF can be offset to improve rejection
 *				of the tracking generator IF.
 *			New console commands for IF Sweep and tracking generator
 *			New menu for tracking generator accessed from Output Menu
 *			SPI now runs at 16MHz (was at 1MHz - oops!)
 *			Additional functions in ui.cmd to allow signed frequency entry.
 *			
 *		Version 3.0f Changes by M0WID
 *		
 *		Version 0.03
 *			renamed simpleSA.  Doesn't seem that simple to me!
 *			First go at bandscope mode
 *			VSPI reduced to 10Mhz as some boards will not run at 16MHz
 *			Put onto github - lets see how it works!  Version numbering changed - still in beta!
 *			
 *		Version 0.1
 *			Tracking generator now can be used as a signal generator 
 *			Web page for signal generator
 *			RX sweep for testing the SI4432 FIR filters
 *			Output range of signal generator increased by also reducing SI4432 output power as well as uing attenuator
 *			Storage feature - temporary only not to disk - added to web page traces
 *			X grid lines added to web chart
 *			
 *		Version 0.11 (pending)
 *			Fix scaling for track gen frequency on web
 *			Axis Y2 on web chart is hidden if relevant traces not enabled
 *			Add self-calibrate
 *			
 */


#include "simpleSA.h"				// Definitions needed by the whole program
#include <Arduino.h>			// Basic Arduino definitions
#include <SPI.h>				// Serial Peripheral Interface library
#include <Wire.h>				// I2C library
#include "si4432.h"				// Si4432 tranceiver class definitions and prototypes
#include "pE4302.h"				// PE4302 attenuator class
#include "cmd.h"				// Command processing functions
#include "marker.h"				// Marker class


#if USE_WIFI					// M0WID - We need the following if using WiFi

	#include "simpleSA_wifi.h" 	// Our WiFI definitions
	#include <WiFi.h>			// ESP32 WiFi support library
	#include <AsyncTCP.h>		// Asynchronous TCP library for Espressif MCUs
	#include "SPIFFS.h"			// ESP32 built-in "file system"

#endif

#include <TFT_eSPI.h>			// TFT_eSPI library
#include <Preferences.h>		// Library to save and restore configuration information
#include "preferences.h"		// Functions to write/read settings and config

#include "ui.h"					// Touch screen interface definitions


/*
 *	Note the actual definitions for display and touch screen pins used are defined
 *	in the file "M0WID_Setup_ILI9341_TinySA.h" in the "User_Setups" directory of
 *	the "TFT_eSPI" library.
 *
 *	These are based on using HSPI (spi2) for display and VSPI (spi3) for the SI4432s
 *	and the attenuator module.
 *
 *	They are listed here just for reference; those not defined in the "TFT_eSPI"
 *	library are defined in the various other files comprising the program:
 *
 *		GPIO-0			SD_CS		Reserved for SD card chip select
 *		GPIO-1			RX0			Used by USB
 *		GPIO-2			TFT_RST		TFT Reset; Could be set to -1 if using processor reset
 *		GPIO-2			tinySA_led	The on-board LED flashes on data transfer
 *		GPIO-3			TX0			Used by USB
 *		GPIO-4			SI_RX_CS	RX Si4432 Transceiver chip select
 *		GPIO-5			SI_TX_CS	TX Si4432 Transceiver chip select
 *		GPIO-6 to 11			Reserved for the Flash memory
 *		GPIO-12/MISO2	TFT_MISO	Display data input (to processor)
 *		GPIO-13/MOSI2	TFT_MOSI	Display data output (from processor)
 *		GPIO-14/CLK2	TFT_SCLK	Display SPI clock
 *		GPIO-15			TFT_CS		Display chip select
 *		GPIO-16			
 *		GPIO-17
 *		GPIO-18/CLK		VSPI_SCLK	Transceiver & Attenuator SPI clock
 *		GPIO-19/MISO	VSPI_SDO	Transceiver & Attenuator SPI data in (to processor)
 *		GPIO-21/SDA		SDA			PCF8575 Data line (VK3PE Implementation only)
 *		GPIO-21/PE4302_LE			PE4302 attenuator Latch Enable (serial attenuator option)
 *		GPIO-22/SCL		SCL			PCF8575 Clock line (VK3PE Implementation only)
 *		GPIO-23/MOSI	VSPI_SDI	Transceiver & Attenuator SPI data out (from processor)
 *		GPIO-25			TFT_LED		Display backlight intensity (PWM)
 *		GPIO-26			TOUCH_CS	Touch screen chip select (in TFT_eSPI library setup)
 *		GPIO-27			TFT_DC		Display data/command select line
 *		GPIO-32			ENC_PB		Reserved for encoder pushbutton switch
 *		GPIO-33			TS_INT		Reserved for touch screen interrupt request
 *		GPIO-33			ENC_BB		or encoder backup button
 *		GPIO-34			ENC_B		Reserved for encoder pin "B" (input only pin)
 *		GPIO-35			ENC_A		Reserved for encoder pin "A" (input only pin)
 *		GPIO-36						Sensor_VP (input only pin)
 *		GPIO-39						Sensor_VN (input only pin)
 *		RX0							USB Receive
 *		TX0							USB Transmit
 */


/*
 *	The "sprites" are a method supported by the "TFT_eSPI" library that  allow faster
 *	updates of the display and reduces flicker. We create three; one for the scan image
 *	proper, one for the data at the top of the screen and a separate one for the data
 *	at the top of the screen. We don't use one for the touch screen menus as there is
 *	no flicker problem there.
 */

	TFT_eSPI	tft		= TFT_eSPI();				// The TFT display object proper
	TFT_eSprite img		= TFT_eSprite ( &tft );		// Sprite for the chart drawing
	TFT_eSprite tSprite = TFT_eSprite ( &tft );		// Sprite for the top of chart display
	TFT_eSprite sSprite = TFT_eSprite ( &tft );		// Sprite for the side of chart display
	TFT_eSprite gainScaleSprite = TFT_eSprite ( &tft );		// Sprite for the gain scale

	TFT_eSPI_Button key[SIG_KEY_COUNT];					// Used for signal generator modes for simplicity



/*

 * Definition for signal generator keys
 */

	sig_key_t sig_keys[SIG_KEY_COUNT] = {
		// x, y, width, height, normal colour, active colour, text
		// x and y are mid points
		{ 18,  			88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 0	100MHz+
		{ 18+   NUM_W, 	88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 1	10MHz+
		{ 18+ 2*NUM_W,  88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 2	1MHz+
		{130,		    88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 3	100kHz+
		{130+   NUM_W,  88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 4	10kHz+
		{130+ 2*NUM_W,  88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 5	1kHz+
		{237,		    88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 6	100Hz+
//		{237+   NUM_W,  88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 10Hz+	Pointless - SI4432 has insufficient resolution and huge drift!
//		{237+ 2*NUM_W,  88,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 1Hz+
	
		{ 18,  		   126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 7	100MHz+
		{ 18+   NUM_W, 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 8	10MHz+
		{ 18+ 2*NUM_W, 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 9	1MHz+
		{130,		   126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 10	100kHz+
		{130+   NUM_W, 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 11	10kHz+
		{130+ 2*NUM_W, 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 12	1kHz+
		{237	     , 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 13	100Hz+
	//	{237+   NUM_W, 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 10Hz+	Pointless - SI4432 has insufficient resolution and huge drift!
	//	{237+ 2*NUM_W, 126,	NUM_W, 	NUM_H,	TFT_WHITE,	TFT_CYAN, "", ""},	// 1Hz+
		
		{ 45,  25,	KEY_W, 	KEY_H,	TFT_WHITE,	TFT_CYAN, "SALo", "SALo"},	// 14	SALo
	//	{ 45, 165,	KEY_W, 	KEY_H,	TFT_WHITE,	TFT_GREEN, "FM", "FM on"},	// xx	FM (frequency Modulation) on/off
	//	{105, 165,	KEY_W, 	KEY_H,	TFT_WHITE,	TFT_GREEN, "AM", "AM on"},	// xx	AM (amplitude modulation) on/off
		{230, 175,	KEY_W, 	KEY_H,	TFT_WHITE,	TFT_GREEN, "ON", "OFF"},	// 15	ON/OFF (Sig gen output on/off)
		{285,  25,	KEY_W, 	KEY_H,	TFT_WHITE,	TFT_CYAN, "Menu", "Menu"},	// 16	When pressed launch menu
		{230,  25,	KEY_W, 	KEY_H,	TFT_WHITE,	TFT_CYAN, "123", "123"}		// 17	When pressed keypad to enter frequency
	};

/*
 *	We create four sprites for the markers and an array of their addresses. The addresses
 *	will be passed to the marker objects when we initialize them in the "setup" function.
 *
 *	It would make more sense to actually create these in the marker itself, but any attempts
 *	to do that caused newer versions of the "TFT_eSPI" library to crash or do goofy things.
 */

	TFT_eSprite mkr1	= TFT_eSprite ( &tft );		// Sprites for the markers
	TFT_eSprite mkr2	= TFT_eSprite ( &tft );
	TFT_eSprite mkr3	= TFT_eSprite ( &tft );
	TFT_eSprite mkr4	= TFT_eSprite ( &tft );

	TFT_eSprite* mSprites[MARKER_COUNT] = { &mkr1, &mkr2, &mkr3, &mkr4 };


/*
 *	Create an array of un-initialized markers. We'll initialize them in the "setup"
 *	function.
 */

	Marker marker[MARKER_COUNT];					// Array of marker objects


/*
 *	These are used for positioning the markers:
 */

	peak_t	peaks[MARKER_COUNT];					// Peaks in the current scan
	peak_t	oldPeaks[MARKER_COUNT];					// Peaks in the previous scan


/*
 *	The "vspi" object handles communications between the processor and the serial
 *	version of the PE4302 attenuator and the Si4432 modules. If we ever implement
 *	use of the SD card memory on the display, it will also use the VSPI bus.
 *
 *	It's created as a pointer so it can be passed to the objects that use it.
 */

	SPIClass* vspi = new SPIClass ( VSPI );			// Create VSPI object and a pointer to it


/*
 *	Constructors for PE4302 object - which one is used depends on the type set in My_SA.h
 */

#if ( PE4302_TYPE == PE4302_PCF)					// Create the PCF8574 attenuator object
	PE4302 att ( PCF8574_ADDRESS );
#endif

#if ( PE4302_TYPE == PE4302_GPIO )					// The parallel mode one
	PE4302 att ( DATA_16, DATA_8, DATA_4, DATA_2, DATA_1, DATA_0 );
#endif

#if ( PE4302_TYPE == PE4302_SERIAL )				// The serial mode one
	PE4302 att (vspi, PE4302_LE );
#endif


/*
 *	Create the transceiver objects:
 */

	Si4432	rcvr ( vspi, SI_RX_CS, RX_4432 );			// Create object for the receiver
	Si4432	xmit ( vspi, SI_TX_CS, TX_4432 );			// And the transmitter (local oscillator)

#ifdef TG_IF_INSTALLED
	Si4432	tg_if ( vspi, SI_TG_IF_CS, TGIF_4432 );			// Create object for the tracking generator IF SI4432
#endif

#ifdef TG_LO_INSTALLED
	Si4432	tg_lo ( vspi, SI_TG_LO_CS, TGLO_4432 );			// Create object for the tracking generator LO SI4432
#endif


/*
 *	Global definitions:
 */

bool			tgIF_OK;					// true if the tracking generator IF SI4432 is present and initialised OK
bool			tgLO_OK;					// true if the tracking generator LO SI4432 is present and initialised OK

uint8_t			numberOfWebsocketClients;	// How many connections
uint16_t		wiFiPoints;					// Push data to the wifi clinets when this many points collected
unsigned long 	wiFiTargetTime = WIFI_UPDATE_TARGET_TIME;
unsigned long 	websocketInterval = WEBSOCKET_INTERVAL;
uint16_t		websocketFailCount;

#ifdef USE_WIFI
// Json document buffers
//size_t capacity = JSON_ARRAY_SIZE ( MAX_WIFI_POINTS + 1 )
//						+ ( MAX_WIFI_POINTS + 1 ) * JSON_OBJECT_SIZE ( 2 ) + JSON_OBJECT_SIZE( 5 );

static DynamicJsonDocument jsonDocument ( 4000 );					// Buffer for json data to be pushed to the web clients
static JsonArray Points = jsonDocument.createNestedArray ( "Points" );	// add Points array
#endif

/*
 * Variables to determine size of grid and waterfall
 * In Bandscope mode the grid is reduced.  In future it may be possible to add
 * a waterfall to the main sweep, but not yet
 */
uint16_t	gridHeight = GRID_HEIGHT;
uint16_t	gridWidth = DISPLAY_POINTS;
uint16_t	yGrid = Y_GRID;					// no of grid divisions
uint16_t	yDelta = gridHeight / yGrid;		// no of points/division
uint16_t	xGrid = X_GRID;	
uint16_t	xOrigin = X_ORIGIN;
uint16_t	yOrigin = Y_ORIGIN;	
uint16_t	displayPoints = DISPLAY_POINTS;	
uint16_t	xDelta = displayPoints / xGrid;
uint16_t	waterfallHeight = WATERFALL_HEIGHT;
int16_t		maxGrid;
int16_t		minGrid;

/*
 * Some varibales for the various operating modes
 */
uint16_t		tinySA_mode = SA_LOW_RANGE;	// Low frequency range
const	char	*modeText[] = { "SALo", "SAHi", "SGLo", "SGHi", "IFSw", "0SpL", "0SpH", "BScp", "RXSw" }; // For mode display


float			bandwidth;					// The current bandwidth (not * 10)
unsigned long	delaytime = 2000;			// delay time to allow SI4432 filters to settle

uint32_t		steps = displayPoints;		// Number of frequency steps in the sweep
uint32_t		sweepPoints;				// Number of points in the sweep. Can be more than DISPLAY_POINTS if RBW is set less than video resolution
uint32_t		startFreq = 0;				// Default start frequency is 0MHz
uint32_t		stopFreq  = 100000000;		// Default stop frequency is 100MHz
uint32_t		tempIF;						// IF used for this sweep.  Changes if Spur reduction is on
double			dBadjust;					// Sum of attenuation, external gain, calibration offset and RBW correction

uint16_t		bpfCalibrate;				// set true if a SI4432 bandpass filter calibration run is taking place
uint16_t		bpfCount;					// no of bandpass filters available

/*
 * Variables for offset frequency tuning (used in Bandscope mode)
 */
int32_t			offsetFreq;					//  Frequency offset from nominal setting
int16_t			offsetStep;					//  increments by one at each reading
int16_t			offsetValue;				//  Offset value to be written to Si4432
int16_t			offsetIncrement;			//  Increment of offsetValue per reading
int32_t			offsetFreqIncrement;		//  Increment offsetFreq per reading
unsigned long	offsetDelayTime = 5000;		//	Delay time when using frequency offset to change frequency


int				VFO = RX_4432;				// Set current VFO for command parser to the receiver Si4432

int				gainReading;				// Current preamp gain (will vary during a scan if AGC enabled)
bool			AGC_On;						// Flag indicates if Preamp AGC is enabled
uint8_t			AGC_Reg;					// Fixed value for preampGain if not auto

uint8_t			showRSSI = 0;				// When zero don't show it (serial output only)

int 			changedSetting = true;		// Something in the "setting" structure changed
int				updateSidebar = false;		// Flag to indicate update of sidebar is needed

// UI functions
extern	uint8_t	ui_mode;					// What mode we are in (in "ui.cpp")
extern	void 	StartSigGenMenu ( void );	// Function to launch sig gen menu
extern	void 	StartSigGenFreq ( void );	// Function to set frequency
extern	void	ResetSAMenuStack ( void );	// Reinitialise stack for SA mode
extern	void	ResetIFsweepMenuStack ( void );	// Reinitialise stack for IF Sweep mode
extern	void	ResetRXsweepMenuStack ( void );	// Reinitialise stack for IF Sweep mode
extern	void	ResetBandscopeMenuStack ( void );	// Reinitialise stack for Bandscope mode

extern	void	ShowSplash ( void );		// Displays the splash screen

extern void		pushSettings ();
extern void		pushIFSweepSettings ();
extern void		pushRXSweepSettings ();
extern void		pushBandscopeSettings ();


/*
 * Variables for IFSweep Mode
 */
uint32_t  	startFreq_IF = IF_SWEEP_START;
uint32_t	stopFreq_IF = IF_SWEEP_STOP;
uint32_t	sigFreq_IF = 15000000;		// 15 Mhz reference

/*
 * Variables for RXSweep Mode
 */
uint32_t  	startFreq_RX = RX_SWEEP_START;
uint32_t	stopFreq_RX = RX_SWEEP_STOP;
uint32_t	sigFreq_RX = 15000000;		// 15 Mhz reference

/*
 *	Variables for timing websocket event checks:
 */

unsigned long	lastWebsocketMicros;			// For timing between websocket events
unsigned long	loopStartMicros;				// For timing the scan
//unsigned long	loopMicros;						// To report the scan time


/*
 *  Variables for measuring sweep time:
 */

unsigned long	sweepStartMicros;			// For timing the scan
unsigned long	lastSweepStartMicros;		// For timing the scan
unsigned long	sweepMicros;				// To report the scan time

uint32_t	sweepCount;					// Used to inhibit handling Wifi until
										// two sweeps have been done and WiFi
										// has stabilized


/*
 *	These arrays contain the data for the various scan points; they are used in
 *	here and in the "TinySA_wifi" modules:
 */

uint8_t		myData[SCREEN_WIDTH+1];
uint8_t		myStorage[SCREEN_WIDTH+1];
uint8_t		myActual[SCREEN_WIDTH+1];
uint8_t		myGain[SCREEN_WIDTH+1];		// Preamp gain
uint32_t	myFreq[SCREEN_WIDTH+1];		// Frequency for XML file

uint16_t	peakLevel;						// Current maximum signal level
uint16_t	oldPeakLevel;					// Old maximum signal level
uint16_t	peakIndex;
uint16_t	peakGain;						// Actual gain at the peak (ie minimum gain)

static int		old_settingAttenuate = -1000;
static int		old_settingPowerGrid = -1000;
static int		old_settingMax = -1;
static int		old_settingMin = -1;
static double	old_startFreq = -1;
static double	old_stopFreq = -1;
static int		requiredRBW10 = 0;
static int		old_requiredRBW10 = -1;
static int		vbw = 0;
static int		old_vbw = -1;
static int		old_settingAverage = -1;
static int		old_settingSpur = -100;
static int  	old_bandwidth = 0;

int16_t		standalone = true;
uint16_t	spacing = 10000;

bool		paused = false;

uint16_t	sigGenOutputOn = false;
uint32_t 	oldFreq;	// to store the current Signal Generator frequency

/*
 *	"setActualPowerRequested" is set by menu or WiFi. 
 *  When request is set the peak value during the sweep is used to calculate
 *	the offset needed to make the power reading match a user input level
 *	A calibration tool
 */

bool		setActualPowerRequested = false;
float		actualPower = CAL_POWER;			// Defined in "My_SA.h"

int			initSweep = true;		// Flag to indicate sweep needs to restart from the beginning
									// Set when sweep settings change
int16_t		sweepStartDone = false;	// Ensure initialize of sweep is only done once


/*
 *	All the following deal with the optional rotary encoder which could be used
 *	to handle the menu options.
 *
 *	Note - None of the encoder stuff has been implemented yet, but we'll leave the
 *	definitions here for the time being:
 *
 *	Symbols for button events and states (change to UC if we ever use them):
 */

#ifdef USE_ROTARY								// Not defined anywhere!

enum 		buttont_event { shortClickRelease=1, longClick=2, 
							longClickRelease=3, shortBackClickRelease=4,
							longBackClick=5, longBackClickRelease=6,
							buttonRotateUp=7, buttonRotateDown=8 };
							
enum 		button_state { buttonUp, buttonDown, buttonLongDown };

int 		buttonState        = buttonUp;		// The current reading from the encoder switch
int			backButtonState    = buttonUp;		// The current reading from the backup button
int 		buttonEvent        = 0;				// Short click release?
int 		lastButtonRead     = HIGH;			// The previous reading from the encoder switch
int			lastBackButtonRead = HIGH;			// The previous reading from the backup button

uint32_t	lastDebounceTime =   0;				// The last time the encoder switch was toggled
uint32_t	debounceDelay    =  50;				// The debounce time; increase if the output flickers
uint32_t	longPressDelay   = 350;				// The long press time; increase if the output flickers

int32_t		incr;
int32_t		incrBase = 1000000;
int 		incrBaseDigit = 7; 

#endif			// "#ifdef USE_ROTARY"

settings_t			setting;					// Structure to track & save settings
sigGenSettings_t	sigGenSetting;				// settings for signal generator mode
trackGenSettings_t	trackGenSetting;			// parameters for tracking gen mode

Preferences preferences;					// "preferences" is an object to enable
											// saving data to Flash


/*
 *	"setup" initializes everything:
 */

void setup () 
{
bool fsStatus = false;								// True if SPIFFS loads ok

	Serial.begin ( 115200 );						// Start up the USB connection

	tft.begin ();									// Start the display object
	tft.setRotation ( 3 );							// If upside down, change to '1'

/*
 *	Disabling the use of the PSRAM on the WROVER boards for the TFT_eSPI library
 *	should speed things up slightly. We do the same thing for the sprites.
 */

	tft.setAttribute ( PSRAM_ENABLE, false );		// Forces all future Sprites to be created in the on-board RAM area

	preferences.begin ( "tinySA", false );			// We retreive stuff from flash memory
	ReadConfig ();									// Read menu and touch settings
	ReadSettings();									// Read attenuation, level adjustment etc
	ReadSigGenSettings();							// Values for signal generator mode
	ReadTrackGenSettings();							// Values for tracking generator mode

	setting.ShowStorage = false;					// Display stored scan (on or off)
	setting.SubtractStorage	= false;				// Subtract stored scan (on or off)


/*
 *  The touch screen needs to be calibrated. In previous versions, the instructions
 *  were to un-comment the call to the "TouchCalibrate" here the first time you
 *  ran the software and to insert the numbers it gave you into the code.
 *
 *  This is no longer necessary as the configuration can now be done from the touch
 *  acreen menu system, but we leave it here as some displays are nowhere near correct
 *  and if they are way off, you won't be able to access the touch menus at all.
 *
 *  The "config.touch_cal" fed into the "tft.setTouch" function is also reacalled
 *  from the flash memory upon startup, so one should only need to calibrate the
 *  touch screen one time.
 */

//  TouchCalibrate ();						// Comment out after first run

	tft.setTouch ( config.touch_cal );      // Send calibration data to the display

#ifdef BACKLIGHT_LEVEL
	setUpLEDC();							// Set up the backlight control
#endif

 
/*
 *  Display the splash screen:
 */

	ShowSplash ();							// Display the splash screen


/*
 *	Set up the pins used for the VSPI bus used by both SI4432 modules and the serial
 *	mode PE4302 attenuator module and initialize the bus object:
 */

	pinMode ( V_SCLK, OUTPUT );				// SPI Clock is an output
	pinMode ( V_SDO,  INPUT  );				// SDO (MISO) is an input
	pinMode ( V_SDI,  OUTPUT );				// SDI (MOSI) is an output

	digitalWrite ( V_SCLK, LOW );			// Make SPI clock LOW
	digitalWrite ( V_SDI,  LOW );			// Along with MOSI

	vspi->begin ( V_SCLK, V_SDO, V_SDI );	// Start the VSPI: SCLK, MISO, MOSI

	//  SI4432 SPI rated for 10MHz according to data sheet.  Seems OK at 16MHz
	vspi->setFrequency(BUS_SPEED);				// run at 10MHz


//	tft.println("VSPI started");



/*
 * Set the CS pins normally used for the SI4432 to high, so if present they do not interfere
 * with the bus signals
 * 
 */
	pinMode (SI_TG_LO_CS, OUTPUT);
	digitalWrite(SI_TG_LO_CS, HIGH);		// make sure the module doesn't get selected	
	
	pinMode (SI_TG_IF_CS, OUTPUT);
	digitalWrite(SI_TG_IF_CS, HIGH);		// make sure the module doesn't get selected		


/*
 *	Initialize the SI4432 for RX and LO(TX)
 */

	tft.setCursor(0,120);
//	tft.println ( "Initializing TX SI4432" );

	if ( ! xmit.Init ( config.TX_capacitance ) )  					// Initialize the transmitter module
      DisplayError ( ERR_FATAL,
             "LO SI4432 failed",
             "to initialise", NULL, NULL );

//	tft.println( "Initializing RX SI4432" );

	if ( ! rcvr.Init ( config.RX_capacitance ) )					// Initialize the receiver module
      DisplayError ( ERR_FATAL,
             "RX SI4432 failed",
             "to initialise", NULL, NULL );

	bandwidth = rcvr.SetRBW ( setting.Bandwidth10, &delaytime );	// Set initial bandwidth and delaytime
	SetRX ( 0 );													// RX in receive, LO in transmit
	rcvr.SetPreampGain ( setting.PreampGain );
	bpfCount = rcvr.GetBandpassFilterCount();						// no of RBW filters available

	
// If the tracking generator IF SI4432 is defined, then check to see if it is connected
	tgIF_OK = false;

#ifdef TG_IF_INSTALLED
	
		tft.setCursor(0,150);	
		tft.println ( "Initializing track gen IF SI4432" );	

		tgIF_OK = tg_if.Init ( config.tgIF_capacitance );
		if ( tgIF_OK )
		{
			tft.println ("Tracking IF initialised");
		}
		else
		{
	    	DisplayError ( ERR_WARN,
	             "Track gen IF SI4432 failed",
	             "to initialise", NULL, NULL );
		}
#endif



// If the tracking generator LO SI4432 is defined, then check to see if it is connected
	tgLO_OK = false;

#ifdef TG_LO_INSTALLED

		tft.println ( "Initializing track gen LO SI4432" );		
		
		tgLO_OK = tg_lo.Init ( config.tgLO_capacitance );
		if ( tgLO_OK  )
			tft.println ("Tracking LO initialised");
		else
	    {
	    	DisplayError ( ERR_WARN,
	             "Track gen LO SI4432 failed",
	             "to initialise", NULL, NULL );
		}
#endif


/*
 *	Initialize the SPIFFS system
 */

	fsStatus = SPIFFS.begin ();							// Mount the file system

	if ( !fsStatus )									// If we can't access the file system
	{
		Serial.println ( "SPIFFS Mount Failed" );		// Error message to serial output

		DisplayError ( ERR_WARN,
					   "Failed to mount SPIFFS",
					   "Use ESP sketch Data Upload",
					   "In the Arduino IDE",
					   "WiFi Disabled" );
	}

//	printSPIFFS ();							// Print out the contents of SPIFFS to the serial port

#if ( USE_WIFI )										// see My_SA.h

	if ( fsStatus )							// If we can access the file system
	{
		#ifdef USE_ACCESS_POINT				// If using a WiFi access point

			startAP ();						// Start it up

		#else								// Connect to the router using SSID 
											// and password defined in TinySA.h

			Serial.println ( "Connecting..." );				// Indicate trying to connect

			if ( connectWiFi () )							// Connection established?
				Serial.println( "Connected" );				// We are connected!
			else
				Serial.println( "Connection Failed!" );

		#endif											// "#ifdef USE_ACCESS_POINT"


/*
 *	Start the websockets server and event handler
 */

//		tft.println("Starting Websockets");

		webSocket.begin ();
		webSocket.onEvent ( webSocketEvent );
		Serial.println ( "WebSockets started" );
		websocketInterval = WEBSOCKET_INTERVAL;
	
//		tft.println("Building Server");

		buildServer ();								

		IPAddress ipAddress = WiFi.localIP ();		// Get our IP address

		Serial.print   ( "Setup - WiFi access point started - browse to http://" );
		Serial.println ( ipAddress.toString().c_str() );
	}

#endif													// "#if ( USE_WIFI )"

	if ( !USE_WIFI || !fsStatus )						// If the WiFI option is not enabled
		Serial.println ( "\nWiFi not enabled!\n" );


//	Serial.println ( "Initializing PE4302" );

//	tft.println("Initialising PE4302");

	att.Init ();								// Initialize the PE4302 attenuator
	att.SetAtten ( 0 );							// Set the attenuation to zero

//	tft.println("Setup Complete");

	Serial.printf ( "\nsimpleSA %s Initialization Complete\n", PROGRAM_VERSION );

	ShowMenu ();								// Display the menu of commands on serial monitor


/*
 *	Initialize the markers. The objects need the address of the display object and
 *	the individual marker objects previously created.
 */

	for ( int i = 0; i < MARKER_COUNT; i++ )
	{
		marker[i].Init ( mSprites[i], i + 1 );			// Pass in the sprite object
		marker[i].Status ( setting.MkrStatus[i] );		// Set color and enabled status
	}


 	delay ( 3000 );					// Time to read splash and initialize messages - Read fast!
	ClearDisplay ();

	setMode ( setting.Mode );		// setMode initializes stuff for the selected mode
	
	lastWebsocketMicros = micros();

}									// End of "setup"


/*
 * ########################################################################################
 * 
 *	"loop" runs forever and handles all the things needed to make it work.
 *  
 *  #######################################################################################
 */

void loop ()
{

loopStartMicros = micros();

#if USE_WIFI
//Serial.println("l");
	if ( ( numberOfWebsocketClients > 0) || (loopStartMicros - lastWebsocketMicros > websocketInterval)
		|| (loopStartMicros < lastWebsocketMicros) )	// handles rollover of micros()
	{
//		Serial.print("L");
		webSocket.loop ();			// Check websockets for events, but not at first
//		Serial.println("l");
		lastWebsocketMicros = loopStartMicros;
	}

#endif

	CheckCommand ();				// Anything from the serial input?

	if ( ( setting.Mode != SIG_GEN_LOW_RANGE ) || (ui_mode != UI_NORMAL ) )
	{
		UiProcessTouch ();						// Handle the touch screen
		if ( ui_mode != UI_NORMAL )
		{
			initSweep = true;
			return;								// If in menu don't do anything else
		}
	}

/*
 *	Not fully implemented yet. 
 */

	switch ( setting.Mode )
	{
		case SA_LOW_RANGE:
			doSweepLow();				// Spectrum Analyser Low Frequency range
			break;

		case SA_HIGH_RANGE:
			doSweepHigh();				// Spectrum Analyser High Frequency range
			break;
	
		case SIG_GEN_LOW_RANGE: 
			doSigGenLow();				// Signal Generator Low Frequency range
			break;
	
		case SIG_GEN_HIGH_RANGE: 
			doSigGenHigh();				// Signal Generator High Frequency range
			break;

		case IF_SWEEP: 
			doIF_Sweep();				// IF Sweep 
			break;

		case RX_SWEEP: 
			doRX_Sweep();				// RX Sweep 
			break;

		case BANDSCOPE: 
			doBandscope();				// Bandscope Sweep 
			break;

		default:
			DisplayError ( ERR_WARN,
	         "Invalid Mode!",
	         "Mode changed to",
	         "Analayze Low range", NULL );
	         initSweepLow ();

	}								// end of switch
}									// end of loop


/*
 * SetMode initializes various things for the selected mode then changes mode. It is called
 * by the web interface, command line or menu.
 */
void setMode ( uint16_t newMode )
{
	switch ( newMode )
	{
		case SA_LOW_RANGE:
			initSweepLow();
			break;

//		case SA_HIGH_RANGE:
//			initSweepHigh();
//			break;

		case SIG_GEN_LOW_RANGE:
			initSigLow();
			break;

//		case SIG_GEN_HIGH_RANGE:
//			initSigHigh();
//			break;

		case BANDSCOPE:
			initBandscope();
			break;

		case IF_SWEEP:
			initIF_Sweep();
			break;

		case RX_SWEEP:
			initRX_Sweep();
			break;


		default:
			DisplayError ( ERR_WARN,
	         "Invalid Mode!",
	         "Mode not changed",
	         NULL, NULL );
	}
}


/*
 * "menuExit" is called when the user leaves the menu
 * The required action depends on the selected mode, and whether or not the
 * device is already in the selected mode
 */

void menuExit()
{
	switch ( tinySA_mode )
	{
		case SA_LOW_RANGE:
			if ( setting.Mode == SA_LOW_RANGE )
				RedrawHisto();
			else
				initSweepLow();
			break;

		case SA_HIGH_RANGE:
			initSweepHigh();
			break;
	
		case SIG_GEN_LOW_RANGE: 
			initSigLow();
			break;
	
		case SIG_GEN_HIGH_RANGE:
			initSigHigh(); 
			break;

		case IF_SWEEP: 
			if ( setting.Mode == IF_SWEEP )
				RedrawHisto();
			else
				initIF_Sweep();
			break;

		case RX_SWEEP: 
			if ( setting.Mode == RX_SWEEP )
				RedrawHisto();
			else
				initRX_Sweep();
			break;

		case BANDSCOPE: 
			if ( setting.Mode == BANDSCOPE )
				RedrawHisto();
			else
				initBandscope();
			break;
		
		default:
			// add handler here
			break;

	}								// end of switch
}


/*
 * Initialise common to low, high, RX and IF_Sweeps
 */
void init_sweep()
{
	ClearDisplay ();
/*
 *	Set up the "img" Sprite. This is the image for the graph. It makes for faster display
 *	updates and less flicker.
 *
 *	16 bit colour depth is faster than 8 and much faster than 4 bit! BUT - sprites
 *	pushed to it do not have correct colour - 8 bit and it is fine.
 *
 *	All marker sprites are WHITE for now.
 */
 	tft.unloadFont();
 	
 	img.unloadFont();
	img.deleteSprite();
	
	img.setTextSize ( 1 );
	img.setColorDepth ( 16 );
	img.setAttribute ( PSRAM_ENABLE, false );		// Don't use the PSRAM on the WROVERs
	img.createSprite ( 2, gridHeight + 1 );    // Only 2 columns wide


/*
 *  The "tSprite" is used for displaying the data above the scan grid.
 */

	tSprite.deleteSprite();
	tSprite.setRotation ( 0 );
	tSprite.setTextSize ( 1 );
	tSprite.setColorDepth ( 16 );          
	tSprite.setAttribute ( PSRAM_ENABLE, false );		// Don't use the PSRAM on the WROVERs
	tSprite.createSprite ( tft.width() - X_ORIGIN, Y_ORIGIN );


/*
 *  The "sSprite" is used for displaying the data to the side of the scan grid.
 */

	sSprite.unloadFont();	
	sSprite.deleteSprite();
	sSprite.setTextSize ( 1 );
	sSprite.setColorDepth ( 16 );          

	sSprite.setAttribute ( PSRAM_ENABLE, false );		// Don't use the PSRAM on the WROVERs
/*
 *  Create and draw the sprite for the gain scale
 */
	CreateGainScale ();

	// Make sure everything will be reset
	old_settingAttenuate = -1000;
	old_settingPowerGrid = -1000;
	old_settingMax = -1;
	old_settingMin = -1;
	old_startFreq = -1;
	old_stopFreq = -1;
	old_requiredRBW10 = -1;
	old_vbw = -1;
	old_settingAverage = -1;
	old_settingSpur = -100;
	old_bandwidth = 0;

	SetRX ( 0 );										// LO to transmit, RX to receive
	xmit.SetOffset ( 0 );								// make sure frequency offset registers are zero

	xmit.SetDrive ( setting.Drive );					// Set  transmitter power level
	rcvr.SetPreampGain ( setting.PreampGain );

#ifdef TG_IF_INSTALLED
	if (tgIF_OK) {
		tg_if.TxMode ( trackGenSetting.IF_Drive );		// turn on the IF oscillator in tracking generator
	}
#endif

	
#ifdef TG_LO_INSTALLED
	if (tgLO_OK) {
		tg_lo.TxMode ( trackGenSetting.LO_Drive );		// turn on the Local Oscillator in tracking generator
	}
#endif
	
	sweepStartDone = false;		// Make sure this initialize is only done once per sweep
	initSweep = true;
}


/*
 * Initialise the JSON document that is used to push the sweep data to the web clients
 * Used in all the sweep modes
 */
void initChunkSweepDoc (uint32_t startIndex)
{
			jsonDocument.clear ();
			jsonDocument["PreAmp"] = setting.PreampGain;			// Fixed gain
			jsonDocument["mType"] = "chunkSweep";
			jsonDocument["StartIndex"] = startIndex;
			jsonDocument["sweepPoints"] = sweepPoints;
			jsonDocument["sweepTime"] = (uint32_t)(sweepMicros/1000);
}



/*
 *  Initialise high frequency mode sweep.
 */
void initSweepHigh ()
{
	// To be done!

	DisplayError ( ERR_WARN,
         "Sweep not done!",
         "Mode changed to",
         "Analayze Low range", NULL );

	tinySA_mode = SA_LOW_RANGE;
	setting.Mode = tinySA_mode;
}


/*
 *	High freq range sweep - not yet implemented
 * 
 *	Will use signals direct into LO SI4432, which be in receive
 *	no mixer, attenuator or low pass filter
 */

void doSweepHigh ()
{
	DisplayError ( ERR_WARN,
		"Sweep High Range",
		"not implemented.",
		"Low range mode",
		"selected for you!" );

	initSweepLow();
}



/*
 *  Initialise sig gen high frequency mode.
 *  May turn out to not be needed!
 */
void initSigHigh ()
{
	// To be done!

	DisplayError ( ERR_WARN,
         "IF Sweep not done!",
         "Mode changed to",
         "Analayze Low range", NULL );

	tinySA_mode = SA_LOW_RANGE;
	setting.Mode = tinySA_mode;
}



/*
 * High freq range signal generator - not yet implemented
 * May turn out to be included in sig gen mode and auto
 * transition depending on set frequency
 */

void doSigGenHigh ()
{
	DisplayError ( ERR_WARN,
		"Signal Generator High Range",
		"not implemented.",
		"Low range SA mode",
		"selected for you!" );

	initSweepLow();
}






/*
 *	"SetRX"	- Mode 3 is sig gen, 0 is normal (RX as receive, LO on), 1 is both
 *	receiving 2 not used
 */

void SetRX ( int p )
{
	int saRX = p;

	if ( saRX == ( 3 ))								// Both on TX - sig gen mode
	{
		rcvr.TxMode ( sigGenSetting.RX_Drive );				// Put receive module in TX mode 
		xmit.TxMode ( sigGenSetting.LO_Drive );				// Put transmit module in TX mode
	}

	else
	{
		if ( saRX == 0 )							// Normal configuration
		{
			rcvr.RxMode ();							// Put receive module in RX mode
			xmit.TxMode ( setting.Drive );			// Put transmit (LO) module in TX mode
		}

		else if ( saRX == 1 ) 						// Both in receive mode
		{
			rcvr.RxMode ();							// Put receive module in RX mode
			xmit.RxMode ();							// Put transmit module in RX mode
		}

		else if ( saRX == 2 )						// Normal configuration
		{
			rcvr.RxMode ();							// Put receive module in RX mode
			xmit.TxMode ( setting.Drive );			// Put transmit module in TX mode
		}
	}
}


/*
 *	"ClearDisplay" - Function to clear the display.
 */

void ClearDisplay ()
{
	tft.fillScreen ( BLACK );					// Fade to black
}


/*
 *	"textWhite" sets the text size to '1' and the text color to "WHITE".
 */

void textWhite()
{
	tft.setTextSize ( 1 );
	tft.setTextColor ( WHITE );			// Draw white text (transparent background)
}


/*
 * Find out if the touch was in the bounds of the slider
 */
 bool sliderPressed( bool pressed, uint16_t t_x, uint16_t t_y )
 {
 	uint16_t minX = SLIDER_X - 5;
 	uint16_t maxX = SLIDER_X + SLIDER_WIDTH + 2 * SLIDER_KNOB_RADIUS + 5;
 	uint16_t minY = SLIDER_Y;
 	uint16_t maxY = SLIDER_Y + 2 * SLIDER_KNOB_RADIUS;

 	return( ( (t_x >= minX) && (t_x <= maxX) && (t_y >= minY) && (t_y <= maxY) ) && pressed );
 }

float sliderPercent( uint16_t t_x )
{
	float p = (float)(t_x - SLIDER_X - SLIDER_KNOB_RADIUS) * 100.0 / (float)SLIDER_WIDTH;
	//Serial.printf("t_x: %i p: %f SLIDER_X: %i SLIDER_KNOB_RADIUS: %i \n", t_x, p, SLIDER_X, SLIDER_KNOB_RADIUS);
	if ( p > 100.0 )
		p = 100.0;
	if ( p < 0.0 )
		p = 0.0;
	return( p );
}
 

/*
 * Draw a slider control.  Uses the sSprite.
 */

void drawSlider (uint16_t x, uint16_t y, float pos, float value, const char *unit) {

	// range check
	float p = pos;
	if (p < 0) p=0.0;
	if (p > 100.0) p=100.0;
	
	// draw a rectangle first, then bar, then position the "knob" on top
	sSprite.fillSprite(SIG_BACKGROUND_COLOR);
	sSprite.fillRoundRect( SLIDER_KNOB_RADIUS, ( sSprite.height() - SLIDER_BOX_HEIGHT ) / 2,
		SLIDER_WIDTH, SLIDER_BOX_HEIGHT, SLIDER_BOX_HEIGHT/4, SLIDER_BOX_COLOR);

	uint16_t knob_x = pos * SLIDER_WIDTH / 100 + SLIDER_KNOB_RADIUS;
	sSprite.fillRoundRect( SLIDER_KNOB_RADIUS, ( sSprite.height() - SLIDER_BOX_HEIGHT ) / 2,
		knob_x - SLIDER_KNOB_RADIUS, SLIDER_BOX_HEIGHT, SLIDER_BOX_HEIGHT/4, SLIDER_FILL_COLOR);
		

	sSprite.fillCircle(knob_x, sSprite.height()/2, SLIDER_KNOB_RADIUS, SLIDER_KNOB_COLOR);

	// Draw the value
	sSprite.setCursor(SLIDER_WIDTH + 2 * SLIDER_KNOB_RADIUS + 1, SLIDER_KNOB_RADIUS - 3);
	sSprite.printf("%3.0f %s", value, unit);

	
//	Serial.println("drawSlider");
	sSprite.pushSprite(SLIDER_X, SLIDER_Y);
}

/*
 *	"DisplayError" - Added by M0WID to display an error message of up to three lines
 *	on the display.
 *
 *	Modified in Version 2.7 by WA2FZW:
 *
 *		Added another line and error levels. Also use a much better looking font
 *		to display the error message! Instead of painting the entire screen in
 *		the appropriate color for the error level, we use a rounded filled rectangle
 *		around the message; looks really nice!
 */

void DisplayError ( uint8_t severity, const char *line1, const char *line2, const char *line3, const char *line4 )
{
	char line0[20];								// Line 0 of the message
	const char *lines[] = { line0, line1, line2, line3, line4 };		// Pointers to the lines

	ClearDisplay ();							// Fade to black

	if ( severity == ERR_INFO )					// Informational message?
	{
		strcpy ( line0, "Information:" );					// Set line 0
		tft.fillRoundRect ( 0, 40, 320, 150, 10, WHITE );	// White background
	}

	else if ( severity == ERR_WARN )			// Warning message?
	{
		strcpy ( line0, "Warning:" );						// Set line 0
		tft.fillRoundRect ( 0, 40, 320, 150, 10, YELLOW );	// Yellow background
	}

	else if ( severity == ERR_FATAL )			// Fatal error?
	{
		strcpy ( line0, "Fatal Error:" );					// Set line 0
		tft.fillRoundRect ( 0, 40, 320, 150, 10, RED );		// Red background
	}

	tft.setTextColor ( BLACK );						// Black text
	tft.setFreeFont  ( &FreeSansBold9pt7b );		// Select nice font
	tft.setCursor    ( 20, 70 );					// Cursor for the first line

	for ( int i = 0; i < 5; i++ )					// Display the lines
	{
		if ( lines[i] != NULL )						// Ignore any NULL lines
		{
			tft.print ( lines[i] );
			tft.setCursor ( 20, 100 + ( i * 20 ));	// Cursor on the next line
		}
	}

	delay ( DELAY_ERROR * 1000 );			// Allow time to read it

	if ( severity == ERR_FATAL )			// If fatal error
		while ( true ) {}					// Halt execution

	ClearDisplay ();

	tft.setFreeFont  ( NULL );				// Set everything back to the default font
	tft.setTextColor ( WHITE );				// and default text color
	tft.setTextDatum ( TL_DATUM );			// and default position datum
}


/*
 *	"RedrawHisto" - Reset all old values to force redraw of labels
 *	Called when exiting menu and should be called when changed from web
 */

void RedrawHisto ()
{
	delayMicroseconds(200);					// short delay to make sure any SI4432 frequency updates are completed
	initSweep = true;
	memset ( peaks, 0, sizeof ( peak_t ));  // peaks are copied to oldPeaks at start of sweep
	old_settingAttenuate = 1000;
	old_settingPowerGrid = -1000;
	old_settingMax = -1;
	old_settingMin = -1;
	old_startFreq = -1;
	old_stopFreq = -1;
	old_settingAverage = -1;
	old_settingSpur = -100;
	ClearDisplay();
	switch (tinySA_mode)
	{
		case BANDSCOPE:
			DisplayBandscopeInfo();
			break;

		default:
			DisplayInfo();
			break;
			
	}
	DrawFullCheckerBoard();
}


/*
 *	"DisplayInfo" - Draws the background text around the checkerboard. Called
 *	when a setting is changed to set axis labels and top info bar
 */

void DisplayInfo () 
{
const char *averageText[] = { " OFF", " MIN", " MAX", "   2", "   4", "   8" };
const char *referenceOutText[] = { "  30", "  15", "  10", "   4", "   3", "   2", "   1" };

double fStart;
double fCenter;
double fStop;

//   enum { SA_LOW_RANGE, SA_HIGH_RANGE, SIG_GEN_LOW_RANGE, SIG_GEN_HIGH_RANGE, IF_SWEEP, ZERO_SPAN_LOW_RANGE, ZERO_SPAN_HIGH_RANGE, TRACKING_GENERATOR, RX_SWEEP };

	tSprite.fillSprite ( BLACK );
	tSprite.setTextColor ( WHITE );


/*
 *  Update side bar info
 */

	if ( initSweep || changedSetting || updateSidebar )
	{
//		Serial.println ( "DisplayInfo - InitSweep True" );

		sSprite.createSprite ( X_ORIGIN, SCREEN_HEIGHT );

		sSprite.fillSprite( BLACK );

		sSprite.setCursor ( 0, 0 );

		sSprite.setTextColor ( WHITE );
		sSprite.print ( setting.PowerGrid );
		sSprite.println ( "dB" );

		sSprite.setCursor ( 0, CHAR_HEIGHT * 2 );
		sSprite.setTextColor ( DB_COLOR );
		sSprite.printf ( "%4i", maxGrid );

		sSprite.setCursor ( 0, gridHeight + yOrigin );
		sSprite.printf ( "%4i", minGrid );

		sSprite.setTextColor ( WHITE );
		sSprite.setCursor ( 0, HALF_CHAR_H * 8 );

		sSprite.setTextColor ( GREEN );

		if ( setting.Bandwidth10 !=0 )				// 0 = auto
			sSprite.setTextColor ( ORANGE );

		sSprite.println ( "RBW" );

		if ( bandwidth >= 100 )
			sSprite.printf ( "%4.0f\n", bandwidth ); 

		else
			sSprite.printf ( "%4.1f\n", bandwidth );

		sSprite.setTextColor ( WHITE );
		sSprite.setCursor ( 0, HALF_CHAR_H * 13 );
		sSprite.printf ( "VRe\n%4i", vbw );         // Video resolution (not VBW)

		sSprite.setCursor ( 0, HALF_CHAR_H * 18 );

		if ( setting.PreampGain == 0x60 )	// AGC on
		{
			sSprite.setTextColor ( GREEN );
			sSprite.println ( "Gain" );
			sSprite.print ( "auto" );
		}

		else
		{
			sSprite.setTextColor ( ORANGE );		// Show value in red if not auto
			sSprite.println ( "Gain" );

			int lnaGain = 5;						// Assume low gain

			if ( setting.PreampGain & LNAGAIN )		// If LNA is turned on
				lnaGain = 25;						// High range

			int pgaGain = ( setting.PreampGain & PGAGAIN ) * 3;		// 3dB per bit
			sSprite.printf ( "%4i", lnaGain + pgaGain );
		}

		sSprite.setTextColor ( WHITE );

		sSprite.setCursor ( 0, HALF_CHAR_H * 23 );
		sSprite.printf ( "Attn\n%4i", setting.Attenuate );

		sSprite.setCursor ( 0, HALF_CHAR_H * 28 );		// Start at top-left corner
		sSprite.printf ( "Ext\n%4.1f", setting.ExternalGain );			// Place holder for external gain/attenuation value
		sSprite.setTextColor ( WHITE );

		if ( setting.Average )
			sSprite.setTextColor ( AVG_COLOR );

		sSprite.setCursor ( 0, HALF_CHAR_H * 33 );
		sSprite.println ( "Avg" );
		sSprite.print ( averageText[setting.Average] );
		sSprite.setTextColor ( WHITE );

		sSprite.setCursor ( 0, HALF_CHAR_H * 38 );
		sSprite.println ( "Spur" );

		if ( setting.Spur )
			sSprite.print ( "  ON" );
		else
			sSprite.print ( " OFF" );

		sSprite.setCursor ( 0, HALF_CHAR_H * 43 );
		sSprite.println ( "Ref" );

		if ( setting.ReferenceOut >= 0 && setting.ReferenceOut < 7 )
			sSprite.print ( referenceOutText[setting.ReferenceOut] );
		else
			sSprite.print ( " OFF" );

		if (tgIF_OK)
		{
			sSprite.setCursor ( 0, HALF_CHAR_H * 48 );
			sSprite.println ( "Trk" );
	
			if ( trackGenSetting.Mode == 1 )
				sSprite.print ( "  ON" );
			else if (trackGenSetting.Mode == 2 )
				sSprite.print ( " SIG" );
			else
				sSprite.print ( " OFF" );
		}
		
		if ( USE_WIFI )
		{
			sSprite.setCursor ( 0, HALF_CHAR_H * 53 );	//  Show number of connected clients
			sSprite.printf ( "Web\n%4u", numberOfWebsocketClients );
		}

		sSprite.pushSprite ( 0, 0 );
		sSprite.deleteSprite();			// Save memory
	}									// End of "if ( initSweep || changedSetting )"




/*
 *	Update frequency labels at bottom if changed
 */

	tft.setTextColor ( WHITE,BLACK );
	tft.setTextSize ( 1 );

	if (tinySA_mode == IF_SWEEP) {
		fStart = startFreq_IF/1000000.0;
		fCenter = (double) ((( startFreq_IF + stopFreq_IF ) / 2.0 ) / 1000000.0 );
		fStop = stopFreq_IF/1000000.0;
	}
	else if (tinySA_mode == RX_SWEEP) {
		fStart = startFreq_RX/1000000.0;
		fCenter = (double) ((( startFreq_RX + stopFreq_RX ) / 2.0 ) / 1000000.0 );
		fStop = stopFreq_RX/1000000.0;
	}
	else
	{
		fStart = (( (double)setting.ScanStart )/ 1000000.0);		// Start freq
		fCenter = (double) ((( setting.ScanStart + setting.ScanStop ) / 2.0 ) / 1000000.0 );
		fStop = (( (double)setting.ScanStop )/ 1000000.0 );			// Stop freq

	}

	if ( old_startFreq != fStart || old_stopFreq != fStop )
	{
		tft.fillRect ( xOrigin, SCREEN_HEIGHT -
						CHAR_HEIGHT, SCREEN_WIDTH - xOrigin - 1, SCREEN_HEIGHT - 1, BLACK );

		// Show operating mode
		tft.setCursor ( xOrigin + 50, SCREEN_HEIGHT - CHAR_HEIGHT );
		tft.setTextColor ( DB_COLOR );
		tft.printf ( "Mode:%s", modeText[setting.Mode] );
		tft.setTextColor ( WHITE );

 		tft.setCursor ( xOrigin + 2, SCREEN_HEIGHT - CHAR_HEIGHT );

		tft.print ( fStart );
//		tft.print( "MHz" );

		tft.setCursor ( SCREEN_WIDTH - 37, SCREEN_HEIGHT - CHAR_HEIGHT );
		tft.print ( fStop );
//		tft.print ( "MHz");


/*
 *	Show the center frequency:
 */
		tft.setCursor ( SCREEN_WIDTH / 2 - 40 + xOrigin, SCREEN_HEIGHT - CHAR_HEIGHT );
		tft.print ( fCenter );
		tft.print ( "(MHz)" );

		old_startFreq = fStart;				// Save current frequency range
		old_stopFreq = fStop;				// For next time
	}

	tft.setCursor ( 220, SCREEN_HEIGHT - CHAR_HEIGHT );		// Show sweep time
	tft.printf ( "%6ums", sweepMicros / 1000 );

//	tft.setCursor ( 100, SCREEN_HEIGHT - CHAR_HEIGHT );		//  Show number of connected clients
//	tft.print( numberOfWebsocketClients );

 
/*
 *	We use the "tSprite" to paint the data at the top of the screen to avoid
 *	flicker.
 */

	tSprite.setCursor ( 0, 0 );					
	tSprite.print ( "/" );						// Nasty!


/*
 *	Show marker values:
 *
 *	The "xPos" and "yPos" arrays are the coordinates of where to place the marker data.
 *
 *	The "posIndex" variable keeps track of the next available position for the marker
 *	data. If we want fixed positions for each marker, then change the "xPos" and "yPos"
 *	indicies to use "m".
 */

	int xPos[MARKER_COUNT] = { 20, 20, 160, 160 };
	int yPos[MARKER_COUNT] = { 0, CHAR_HEIGHT, 0, CHAR_HEIGHT };
	int	posIndex = 0;

	for ( int m = 0; m < MARKER_COUNT; m++ )
	{
		tSprite.setCursor ( xPos[m], yPos[m] );
		if (( marker[m].isEnabled()) && ( setting.ShowSweep || setting.Average != AV_OFF ))
		{
			tSprite.setTextColor ( WHITE );
			tSprite.printf ( "%u:%5.1fdBm %8.4fMHz", marker[m].Index()+1,
					rssiTodBm ( oldPeaks[m].Level ), oldPeaks[m].Freq / 1000000.0 );
		}
		else
		{
			tSprite.setTextColor ( DARKGREY );
			tSprite.printf ( "%u:", marker[m].Index()+1 );
		}
		posIndex++;
	}
	
	int x = tSprite.width () - 45;
	tSprite.setTextColor ( WHITE );
  
	tSprite.pushSprite ( xOrigin, 0 );				// Write sprite to the display

  	updateSidebar = false;
}													// End of "DisplayInfo"


/*
 *	Draw the complete checkerboard
 *	This can be optimized if needed
 */

void DrawFullCheckerBoard()
{
	for ( int p=0; p<displayPoints; p++ )
	{
		DrawCheckerBoard ( p );

		if ( p > 0 ) 
			img.pushSprite( xOrigin+p-1, yOrigin );
	}

//	Serial.println ( "DrawFullCheckerBoard" );
}


/*
 *	"DrawCheckerBoard" - Paints the grid. It now uses a sprite so no need to
 *	erase the old grid, just draw a new one.
 *
 *	The img sprite is two pixels wide, and the image from the previous data point
 *	is scrolled and then new data point drawn. The data from last is scrolled
 *	so any line from before is retained.
 */

void DrawCheckerBoard ( int x ) 
{
	if ( x == 0 )							// "x" is the sweepStep, if zero
		return;								// then just return.

	if ( x == 1 )
	{
		img.fillSprite ( BLACK );								// Clear the sprite
		img.drawFastVLine ( 0, 0, gridHeight, DARKGREY );		// Draw vertical line at edge

		for ( int y=0; y <= yGrid; y++ )
			img.drawPixel ( 1, y*yDelta, DARKGREY );			// Draw the horizontal grid lines
	}

	else
	{
		img.setScrollRect ( 0, 0, 2,gridHeight, BLACK );	// Scroll the whole sprite
		img.scroll ( -1, 0 );
		int lastStep = x - 1;

		if (( x % xDelta ) == 0 )							// Need a vertical line here
			img.drawFastVLine ( 1, 0, gridHeight, DARKGREY );

		else
			for ( int y = 0; y <= yGrid; y++ )
				img.drawPixel ( 1, y * yDelta, DARKGREY );		// Draw the horizontal grid lines
	}
}


/*
 * Function to work out the y coordinate on img sprite for a given RSSI value
 * Takes into account the display scaling, attenuation and level offset
 */

uint16_t rssiToImgY ( uint8_t rSSI )
{
	int delta = maxGrid - minGrid;
	double y = rssiTodBm ( rSSI );

	y = ( y - minGrid ) * gridHeight / delta;

	if ( y >= gridHeight )
		y = gridHeight-1;

	if ( y < 0 )
		y = 0;

	return gridHeight - 1 - (int) y;
}


/*
 * Function to convert rSSi to dBm
 */

double rssiTodBm ( uint8_t rSSI )
{
	return ( rSSI / 2.0 + dBadjust );
}


/*
 * Function to convert rSSi to dBm
 */

uint8_t dBmToRSSI ( double dBm )
{
	return ( 2 * ( dBm - dBadjust ) );
}


/*
 *  "DisplayPoint" - Display a point on the chart.
 *
 *  The "img" sprite is 2 pixels wide to enable the last points to be also
 *  plotted to make lines look good. The img sprite has been scrolled in
 *  "DrawCheckerBoard".
 */
 
void DisplayPoint ( uint8_t* data, int i, int color )
{
	if ( i < 1 )
		return;

	int lastPoint = i - 1;
	int delta = maxGrid - minGrid;
	double f0 =  data[i] / 2.0 + dBadjust;		// Current point
	f0 = ( f0 - minGrid ) * gridHeight / delta;

	if ( f0 >= gridHeight )
		f0 = gridHeight-1;

	if ( f0 < 0 )
		f0 = 0;

	double f1 = data[lastPoint] / 2.0 + dBadjust;	// Previous point

	f1 = ( f1 - minGrid ) * gridHeight / delta;

	if ( f1 >= gridHeight )
		f1 = gridHeight-1;

	if ( f1 < 0 )
		f1 = 0;

	int Y0 = gridHeight - 1 - (int) f0;
	int Y1 = gridHeight - 1 - (int) f1;

	img.drawLine ( 0, Y1, 1, Y0, color );
}


/*
 *	"DisplayGainPoint" - Added by M0WID to display a scan of the gain setting.
 */

void displayGainPoint ( unsigned char *data, int i, int color )
{
	if ( i == 0 )
		return;

	int lastPoint = i - 1;
	int delta = 50;								// Scale of y axis
	double f0 = ( data[i] ) ;

//	Serial.printf ( "gain %f \n", f );

	f0 = ( f0 ) * gridHeight / delta;

	if ( f0 >= gridHeight )
		f0 = gridHeight - 1;

	if ( f0 < 0 )
		f0 = 0;

	double f1 = ( data[lastPoint] );

	f1 = ( f1 ) * gridHeight / delta;

	if ( f1 >= gridHeight )
		f1 = gridHeight - 1;

	if ( f1 < 0 )
		f1 = 0;

	int Y0 = gridHeight - 1 - (int) f0;
	int Y1 = gridHeight - 1 - (int) f1;

	img.drawLine ( 0, Y1, 1, Y0, color );
}


/*
 *	"CreateGainScale" puts the decibel values for the gain trace into a sprite for 
 *	display at the right side of the grid.
 *	
 *	NOTE Due to temporary error in TFT_eSPI library the inverted colour is used
 *	so TFT_BLUE actually results in TFT_GREEN! 
 */

void CreateGainScale ()
{
	gainScaleSprite.deleteSprite();
	gainScaleSprite.setAttribute ( PSRAM_ENABLE, false );
	gainScaleSprite.setColorDepth ( 16 );							// Using 16 bit (RGB565) colors
	gainScaleSprite.createSprite(CHAR_WIDTH * 2, gridHeight);
	gainScaleSprite.fillSprite(BLACK);
	gainScaleSprite.setPivot( 0, 0 );
	gainScaleSprite.setTextSize ( 1 );
	gainScaleSprite.setTextColor ( TFT_BLUE );		// Draw text (transparent background)  GAIN_COLOR
	int w = gainScaleSprite.width();

//	Serial.printf("Create gain scale - get sprite width %i \n", w);

	if ( w != CHAR_WIDTH * 2 )
	{
		Serial.println ( "Error - no gain scale sprite" );
		return;
	}

	for ( int i = 0; i < 5; i++ )
	{ 
		gainScaleSprite.setCursor ( 0, 2 + ( yDelta * i * 2 ));
		gainScaleSprite.print ( 50 - ( i * 10 ));
	}
}


/*
 *	"CreateGridScale" puts the decibel values for the main trace into a sprite for 
 *	display at the left side of the Bandscope grid.
 *	The gainScaleSprite is reused as there in no need for a gain trace on the bandscope
 *	
 *	NOTE Due to temporary error in TFT_eSPI library the inverted colour is used
 *	so TFT_BLUE actually results in TFT_GREEN! 
 */

void CreateGridScale ()
{
	gainScaleSprite.deleteSprite();
	gainScaleSprite.setAttribute ( PSRAM_ENABLE, false );
	gainScaleSprite.setColorDepth ( 16 );							// Using 16 bit (RGB565) colors
	gainScaleSprite.createSprite(CHAR_WIDTH * 4, gridHeight);
	gainScaleSprite.fillSprite(BLACK);
	gainScaleSprite.setPivot( 0, 0 );
	gainScaleSprite.setTextSize ( 1 );
	gainScaleSprite.setTextColor ( TFT_WHITE );
	int w = gainScaleSprite.width();

//	Serial.printf("Create gain scale - get sprite width %i \n", w);

	if ( w != CHAR_WIDTH * 4 )
	{
		Serial.println ( "Error - no gain scale sprite" );
		return;
	}

	//  Markers at every other line, there are 10 lines
	int16_t valueInterval = (setting.BandscopeMaxGrid - setting.BandscopeMinGrid) / yGrid * 2 ;
	int16_t v = setting.BandscopeMaxGrid;
	int16_t yoffset;
	
	for ( int i = 0; i < 5; i++ )
	{ 
		if (i > 0)
			yoffset = -3;
		else
			yoffset = 0;
		gainScaleSprite.setCursor ( 0, yoffset + ( yDelta * i * 2 ));
		gainScaleSprite.printf ( "%4i", v );
		v = v - valueInterval;
	}
}



/*
 *	"ledcAnalogWrite" - Arduino like analogWrite used for PWM control of backlight.
 *
 *	"value" has to be between 0 and valueMax
 */

void ledcAnalogWrite ( uint8_t channel, uint32_t value, uint32_t valueMax = 255 )
{
	if ( value > valueMax )
		value = valueMax;

	uint32_t duty = ( 8191 / valueMax ) * value;	// Calculate duty, 8191 from 2 ^ 13 - 1
	ledcWrite ( channel, duty );							// write duty to LEDC
}


/*
 *	"setUpLEDC" - Sets up the LEDC PWM for the backlight.
 *
 *	"TFT_BL" is defined in the User_setup.h file in the "TFT_eSPI" library
 *	If BACKLIGHT_LEVEL is not defined then your board uses a resistor instead
 */
#ifdef BACKLIGHT_LEVEL

void setUpLEDC ()
{
	ledcSetup ( LEDC_CHANNEL_0, LEDC_BASE_FREQ, LEDC_TIMER_13_BIT );
	ledcAttachPin ( TFT_LED, LEDC_CHANNEL_0 );
	ledcAnalogWrite ( LEDC_CHANNEL_0, BACKLIGHT_LEVEL );
}

#endif

/*
 *	"TouchCalibrate" - Runs the touchscreen calibration sequence using the
 *	procedure in the "TFT_eSPI" library.
 *
 *	This used to be called from "setup" by removing the comment from the
 *	function call. That can still be done, however, it is now also invoked
 *	from the "CONFIG" menu.
 *
 *	The calibration constants are saved to the flash memory and recalled at
 *	startup, so it need only be done once.
 */
 
void TouchCalibrate ()
{
	uint8_t calDataOK = 0;

	tft.fillScreen ( BLACK );
	tft.setCursor ( 20, 0 );
	tft.setTextFont ( 2 );
	tft.setTextSize ( 1 );
	tft.setTextColor ( WHITE, BLACK );

	tft.println ( "Touch corners as indicated" );

	tft.setTextFont ( 1 );
	tft.println ();

	tft.calibrateTouch ( config.touch_cal, MAGENTA, BLACK, 15 );

	Serial.print ( "\n\n// New calibration data: { " );

	for ( uint8_t i = 0; i < 5; i++ )
	{
		Serial.print ( config.touch_cal[i] );

		if ( i < 4 )
			Serial.print ( ", " );
	}

	Serial.println ( " };\n\n" );

	WriteConfig();							// Save the new calibration data to flash

	tft.fillScreen ( BLACK );
	tft.setTextColor ( GREEN, BLACK);
	tft.println ( "Calibration complete!" );
	tft.println ( "Calibration values sent to Serialport\nand saved to flash." );

	delay ( 3000 );
}


/*
 *	Print out the files in the SPIFFS (SPI Fllat File System)
 *	This requires some files to be loaded into the ESP32's SPIFFS file system
 *	before the capability can be used.
 *
 *	Conditionalized on whether or not WiFi is in use:
 */

void printSPIFFS()
{
	char fileName[25];
	char fileSize[10];

	Serial.println ( "Contents of SPIFFS:" );

	fs::File root = SPIFFS.open ( "/" );		// Open the root object
	fs::File file = root.openNextFile ();		// Open the 1st file

	while ( file )								// Loop through the files
	{
		if ( file.isDirectory () )				// If the file is a directory
		{
			strcpy ( fileName, file.name () );
			Serial.printf ( "  DIR :  %-s\n", fileName );
		}

		else									// File is a regular file
		{
			strcpy ( fileName, file.name() );
			itoa ( file.size(), fileSize, 10 );
			Serial.printf ( "  FILE:  %-25s%10s\n", fileName, fileSize );
		}

		file = root.openNextFile();				// Move to the next file
	}
}