;********************************************************************
;		FS5000 DCU (Digital Control Unit) V2.2
;			  27 October 2009
;			Ray Robinson vk2no
;********************************************************************
; Initialise LCD
; Write a character to the LCD
; Scan the keyboard
; Get the key legend from the buffer
; Do not repeat a key
; A = toggle receiver on/off
; B = toggle bandwidth 300/3000
; C = enter COMMON frequency (receive)
; D = enter DIFFERENT frequency (transmit)
; # = receive
; * = transmit
;--------------------------------------------------------------------
; DEVELOPMENT
; 1/. Changed all routines, so that all "portc" output lines are always HIGH,
; and that they go LOW only when doing something, then return HIGH.
; Used for scanning the keyboard, and loading the LCD display.
; 2/. Changed all routines, so that all "port" output lines are always LOW,
; and that they go HIGH only when doing something, then return LOW.
; Used for loading data into the CONTROL latch, FSET latch, and chip select.
; 3/. Unreliable LCD setup fixed. Was due to LCD enable line being made low
; in the INIT routine, and that first negative edge, clocked in unkown data.
; Making these lines always HIGH, removed this problem.
; 4/. Transmitter frequency load, turns radio OFF! Why?
; 5/. Added variables KEY and TEMP so that variable CHAR is only used for LCD display
; 6/. Made Printed Circuit Board. Rewrite all routines.
; 7/. New PICAXE 40X-1. Requires editor V5.2.7 (Dec 09)
; 8/. New PICAXE 40X-1 has no osc waveforms on external pins, all internal.
; 9/. LCD, keyboard works
; 10/. A key turns radio ON/OFF
; 11/. B key changes bandwidth N/W (Dec09)
; 12/. display status of synth lock line 
; 13/. subtract offset from tx and rx frequency
; 14/. set transmitter LPF 
; 15/. power on/off control (Jan10)
;
;--------------------------------------------------------------------
;
CONSTANTS:
	SYMBOL	TMP	= b0		; Temp
	SYMBOL	TXM	= b1		; Transmitter mode (1=TX, 0=RX)
	SYMBOL	FPTR	= b2		; Frequency pointer
	SYMBOL	FCNT	= b3		; Frequency digit count
	SYMBOL	KEY	= b4		; Key
	SYMBOL	KYOLD	= b5		; old key
	SYMBOL 	ROW	= b6		; Keyboard row
	SYMBOL	COL	= b7		; Keyboard column
	SYMBOL	CNT	= b8		; Keyboard counter
	SYMBOL	KPTR	= b9		; Keyboard pointer
	SYMBOL	CHAR	= b10		; Character store
	SYMBOL	STAT	= b11		; Status
	SYMBOL	FSET	= b12		; FREQUENCY port status
	SYMBOL	CTRL	= b13		; CONTROL port status
	SYMBOL	FSETI = %00000000	; initial FREQUENCY port status
	SYMBOL	CTRLI = %00000000	; initial CONTROL status
	SYMBOL	CMD	= %00000000	; select LCD COMMAND register (bit 4 low)
	SYMBOL	DAT	= %00010000	; select LCD DATA register (bit 4 high)
	SYMBOL	NIBL	= %00001111	; Mask for low nibble
	SYMBOL	NIBH	= %11110000	; Mask for high nibble
	SYMBOL	LCDL1 = 128		; Move LCD to start of line 1
	SYMBOL	LCDL2 = 192		; Move LCD to start of line 2
	SYMBOL	LCDL3 = 207		; Move LCD to last position of line 2
	SYMBOL	LCDL4 = 206		; Move LCD to second last position of line 2
	SYMBOL	RAM1	= $50		; RAM memory START (48 bytes)
	SYMBOL	RAM1E	= $7F		; RAM memory END
	SYMBOL	RAM2	= $C0		; RAM memory START (64 bytes)
	SYMBOL	RAM2E	= $FF		; RAM memory END
	SYMBOL	FQB	= RAM1	; Frequency input buffer
	SYMBOL	RXFQB	= FQB + 7	; Frequency Receiver buffer
	SYMBOL	TXFQB	= RXFQB + 7	; Frequency Transmitter buffer
	SYMBOL	KYB_BUF	= RAM2	; Keyboard buffer start
	SYMBOL	KYB_BUFE	= RAM2E	; Keyboard buffer end
	SYMBOL	LEN	= 15			; Title string length -1
	SYMBOL	KLR0	= LEN + 1		; Keyboard legend row0
	SYMBOL	KLR1	= KLR0 + 12		; Keyboard legend row1
	SYMBOL	KLR2	= KLR1 + 12		; Keyboard legend row2
	SYMBOL	KLR3	= KLR2 + 12		; Keyboard legend row3
	SYMBOL	KLR4	= KLR3 + 12		; Keyboard legend row4
	SYMBOL	RFQI	= KLR4 + 12		; Frequency for rx init
	SYMBOL	TFQI  = RFQI + 7		; Frequency for tx init
	SYMBOL	FROCW	= TFQI + 7		; Frequency offset for rx cw
	SYMBOL	FTOCW = FROCW + 7		; Frequency offset for tx cw
	SYMBOL	DEND	= FTOCW + 7		; Data end 
	DATA 		0,("FS5000 DCU  V2.2")	; Title string
	DATA		KLR0,	("........123A")	; row 0 keyboard legend
	DATA		KLR1,	("........456B")	; row 1 keyboard legend
	DATA		KLR2,	("........789C")	; row 2 keyboard legend
	DATA		KLR3,	("........*0#D") 	; row 3 keyboard legend  
	DATA		KLR4,	("............") 	; row 4 keyboard legend  
	DATA		RFQI, ("0070300")		; frequency to initialise receiver
	DATA		TFQI, ("0360000")		; frequency to initialise transmitter
	DATA		FROCW,("0000100")		; Frequency offset for receiver in CW mode
	DATA		FTOCW,("0020000")		; Frequency offset for transmitter in CW mode
;
;--------------------------------------------------------------------
; uses no variables
; calls INIT, LCD_INIT, TITLE, KYBD_SCAN, KYBD_CHK, ACT
;
START:					; here on reset and power on
	gosub INIT				; initialise ports and variables
	gosub LCD_INIT			; initialise the LCD display
	gosub TITLE				; write the title
	gosub BW				; set the bandwidth
	gosub RX				; set receive mode
LOOP1:	
	gosub KYBD_SCAN			; scan the keyboard
	gosub	KYBD_CHK			; identify the key
	gosub ACT				; action the key
	gosub	SLK				; check SYNTH LOCK line
	goto  LOOP1				; loop
;
;********************************************************************
;ok		Action the key
;********************************************************************
; uses KYOLD, KEY
; calls LCD_CHAR,BW,RX
; on entry with KEY = $FF, nothing happens
; on entry with KEY = a valid ASCII character, it is actioned
; on entry with KEY = KYOLD, nothing happens (as this is a repeat)
; when returning from a subroutine, make sure KEY, KYOLD have not changed
;
ACT:
	if KEY = $FF then ACTX			; exit if no key found
	if KYOLD = KEY then ACTX1		; jump if this is a repeat
	KYOLD = KEY 				; save key (prevent a repeat)
;	CHAR = KEY					; diagnostic, write the character to LCD
;	gosub LCD_CHAR				; diagnostic, write the character to LCD
;	gosub DIAG1					; diagnostic, toggle pin 40, endless loop
	if KEY = "0" then GFQ			; goto get frequency digit
	if KEY = "1" then GFQ			; goto get frequency digit
	if KEY = "2" then GFQ			; goto get frequency digit
	if KEY = "3" then GFQ			; goto get frequency digit
	if KEY = "4" then GFQ			; goto get frequency digit
	if KEY = "5" then GFQ			; goto get frequency digit
	if KEY = "6" then GFQ			; goto get frequency digit
	if KEY = "7" then GFQ			; goto get frequency digit
	if KEY = "8" then GFQ			; goto get frequency digit
	if KEY = "9" then GFQ			; goto get frequency digit
	if KEY = "A" then AX			; goto turn radio on routine (will be ATU tune)
	if KEY = "B" then BW			; goto set BANDWIDTH routine
	if KEY = "C" then RXFQ			; goto set RECEIVER frequency routine
	if KEY = "D" then TXFQ			; goto set TRANSMITTER frequency routine
	if KEY = "#" then RX			; goto RECEIVE routine
	if KEY = "*" then TX			; goto TRANSMIT routine
;
	goto ACTX1					; exit
ACTX:
	KYOLD = 0					; clear for new button press
ACTX1:
	return					; finished
;
;********************************************************************
;ok		set Receiver mode
;********************************************************************
; entry, nothing required
; uses STAT,CTRL,RXFQB,FPTR
; calls SFRQ
;
RX:	TXM = 0				; set rx mode
	STAT = CTRL & %11100011		; clear Tx, RF, Tdc bits to 0 (set rx mode)
	CTRL = STAT				; save control port status
	pins = CTRL				; load frequency port
	high portc 6			; latch control data
	low portc  6			; latch control data
;
	gosub SFRQ				; set the frequency
;
	pins = %00000000			; set lines low
	return				; finished
;
;********************************************************************
;ok		set Transmit mode
;********************************************************************
; entry, nothing required
; uses STAT,CTRL,TXFQB,FPTR
; calls SFRQ,SFIL
;
TX:	TXM = 1				; set tx mode
;	STAT = CTRL & %00000100		; mask for Tdc bit
;	if STAT > 0 then TXX		; jump to exit if bit high
;
	STAT = CTRL & %11100011		; clear Tdc, Tx, RF bits to 0 
	CTRL = STAT | %00000100		; set Tdc bit to 1
;	CTRL = STAT				; save control port status
	pins = CTRL				; load frequency port
	high portc 6			; latch frequency data
	low portc 6 			; latch frequency data
;
 	gosub SFRQ				; set the frequency
;
	gosub SFIL				; set the transmitter LPF
;
;	STAT = CTRL | %00001000		; set RF bit to 1
;	CTRL = STAT				; save control port status
;	pins = CTRL				; load frequency port
;	high 6				; latch frequency data
;	low  6				; latch frequency data
;
TXX:	pins = %00000000			; set lines low
	return				; finished
; 
;********************************************************************
;ok		Set the transmitter LPF
;********************************************************************
; entry, nothing required
; uses PTR,CHAR,STAT,FSET,TXFQB
; calls nothing
;
SFIL:	PTR = TXFQB				; point to the transmit frequency buffer
	peek PTR,CHAR			; get tens mhz digit
	STAT = CHAR - 48			; convert from ASCII to decimal
	FSET = STAT * 10			; multiply by 10
	PTR = TXFQB + 1			; point to the transmit frequency buffer
	peek PTR,CHAR			; get units mhz digit
	STAT = CHAR - 48			; convert from ASCII to decimal
	PTR = FSET + STAT			; freq in mhz (0-30)
;
	if PTR < 3  then SFIL3		; set LPF filter to 3 mhz
	if PTR < 4  then SFIL4		; set LPF filter to 4 mhz
	if PTR < 6  then SFIL6		; set LPF filter to 6 mhz
	if PTR < 8  then SFIL8		; set LPF filter to 8 mhz
	if PTR < 12 then SFIL12		; set LPF filter to 12 mhz
	if PTR < 16 then SFIL16		; set LPF filter to 16 mhz
	if PTR < 20 then SFIL20		; set LPF filter to 20 mhz
	  STAT = 0				; set LPF filter to 30 mhz
	  goto SFILS
SFIL3:  STAT = 1
	  goto SFILS
SFIL4:  STAT = 2
	  goto SFILS
SFIL6:  STAT = 3
	  goto SFILS
SFIL8:  STAT = 4
	  goto SFILS
SFIL12: STAT = 5
	  goto SFILS
SFIL16: STAT = 6
	  goto SFILS
SFIL20: STAT = 7
;
SFILS: FSET = STAT & %00000111	; set LPF
	 pins = FSET			; load LPF port
	 high portc 5			; latch LPF data
	 low portc  5			; latch LPF data
;	
	pins = %00000000			; clear lines
	return
;
;********************************************************************
;ok		Diagnostic
;********************************************************************
; it should never get here
; catch routine, if there is a code error
;
DIAG1:	high 7	; make PICAXE pin 40 high
		low 7		; make PICAXE pin 40 low
		goto DIAG1	; repeat
;
;********************************************************************
;ok		Set the frequency
;********************************************************************
; uses FPTR, FSET, FCNT, STAT, CHAR, TMP, FTOCW, FROCW, CNT
; gets each rx or tx frequency digit
; subtracts the rx or tx offset
; loads each digit into the FS5000
; calls nothing
;
SFRQ:	STAT = FSET | %00100000		; set FMAN bit to 1 (initiates set FREQ)
	pins = STAT				; load FREQ SET port
	high portc 5			; latch FREQ port
	low portc 5				; latch FREQ port
	pause 10				; wait 10ms
;
	CNT = 0					; set the borrow flag to zero
	for FCNT = 6 to 0	step -1	; do the 7 frequency digits
;
	if TXM = 0 then SFR1			; jump if rx mode
	FPTR = TXFQB + FCNT				; point to the tx frequency
	goto SFR2					; jump
SFR1:	FPTR = RXFQB + FCNT				; point to the rx frequency
;
;	STAT = FPTR + FCNT		; point to the frequency buffer digit
SFR2:	peek FPTR,CHAR			; get freq digit
	STAT = CHAR - 48			; convert from ASCII to decimal
	CHAR = STAT & %00001111		; clear top bits (freq digit is in CHAR)
;
;----------------------------------
; this section subtracts the offset
;
	if TXM = 0 then SFR3			; jump if rx mode
	FPTR = FTOCW + FCNT			; point to the tx offset frequency
	goto SFR4					; jump
SFR3:	FPTR = FROCW + FCNT			; point to the rx offset frequency
;	
SFR4:	read FPTR,TMP				; get offset digit
	STAT = TMP - 48				; convert from ASCII to decimal
	TMP = STAT + CNT				; add borrow flag
	STAT = TMP & %00001111			; clear top bits
	TMP = STAT					; move it to TMP (offset digit is in TMP)
;
	if CHAR >= TMP then SFR5		; jump if no borrow
	STAT = CHAR + 10				; add decimal 10
	CHAR = STAT					; move it to CHAR
	CNT = 1					; set borrow flag to 1
	goto SFR6					; jump
;	
SFR5: CNT = 0					; set borrow flag to 0
SFR6: STAT = CHAR - TMP				; subtract offset from this digit	
	CHAR = STAT & %00001111			; clear top bits
;
;--------------------------
;
	STAT = CHAR | %00100000		; set FMAN bit to 1
	CHAR = FSET & %11000000		; clear bits 0 to 5
	FSET = CHAR | STAT		; combine bits
	pins  = FSET			; load digit into FREQ SET port
	high portc 5			; load FREQ digit
	low  portc 5			; load FREQ digit
	pause 10				; wait 10ms
;
	STAT  = FSET | %00010000	; set FC bit to 1 (set FREQ digit)
	pins  = STAT			; load FREQ SET port
	high portc 5			; latch FREQ digit
	low  portc 5			; latch FREQ digit
	pause 10				; wait 10ms
;
	pins  = FSET			; clear FC bit to 0, load FREQ SET port
	high portc 5			; latch FREQ port
	low  portc 5			; latch FREQ port
	pause 10				; wait 10ms
;
	next FCNT				; continue
;
	CHAR = FSET
	FSET = CHAR & %11000000		; clear bits 0 to 5
	pins  = FSET			; load FREQ SET port(finished setting FREQ)
	high portc 5			; latch FREQ port
	low portc 5				; latch FREQ port
	pause 10				; wait 10ms
;	
	pins = %00000000			; clear lines
	return				; finished
;
;********************************************************************
;ok		Get the Receiver Frequency
;********************************************************************
; uses TXM, FCNT
; calls LCD_RFQ
;
RXFQ: TXM = 0					; set receiver mode
	FCNT = 0					; reset digit count
;
	gosub LCD_RFQ				; clear the LCD rx display
	return
;
;********************************************************************
;ok		Get the Transmitter Frequency
;********************************************************************
; uses TXM, FCNT
; calls LCD_TFQ
;
TXFQ: TXM = 1					; set transmitter mode
	FCNT = 0					; reset digit count
;
	gosub LCD_TFQ				; clear the LCD tx display
	return					; finished
;
;********************************************************************
;ok		Get the Frequency
;********************************************************************
; future.....ADD A LIMIT (500khz - 30mhz)
; get 7 digits from the keyboard to make the frequency
; uses FPTR, FCNT, FQB, KEY, CHAR, TXM, TXFQB, RXFQB
; enters with an ASCII character 0 to 7 in KEY
; loads 7 digits into the input buffer
; displays the difits
; moves the frequency into the rx or tx buffer
; calls LCD_FQ, LCD_CMD, LCD_CHAR
;
GFQ:	FPTR = FQB + FCNT				; point to the input frequency buffer
	if FCNT > 6 then GFQX			; exit if more than 7 digits
	poke FPTR,KEY				; save digit
;
	CHAR = KEY					; move to CHAR
	gosub LCD_CHAR				; display the character
	if FCNT != 1 then GFQ1			; test for decimal point position in display
	CHAR = "."					; load a decimal point	
	gosub LCD_CHAR				; send a character
;
GFQ1:	FCNT = FCNT + 1				; increment digit count
	if FCNT < 7 then GFQX			; exit if less than 7 digits
;
	if TXM = 0 then GFQR			; jump if rx mode
;
	for FCNT = 0 to 6				; transfer the frequency to the tx buffer
	FPTR = FQB + FCNT				; point to the frequency buffer
	peek FPTR,CHAR				; get digit
	FPTR = TXFQB + FCNT			; point to the tx frequency buffer
	poke FPTR,CHAR				; save digit
	next FCNT					; continue
	goto GFQX					; exit
;
GFQR:	for FCNT = 0 to 6				; transfer the frequency to the rx buffer
	FPTR = FQB + FCNT				; point to the frequency buffer
	peek FPTR,CHAR				; get digit
	FPTR = RXFQB + FCNT			; point to the receive frequency buffer
	poke FPTR,CHAR				; save digit
	next FCNT					; continue
;	
GFQX:	return					; finished
;
;********************************************************************
;ok		Turn  radio ON and OFF
;********************************************************************
; uses STAT, CTRL, TXM
; calls nothing
; toggles CONTROL bit 0 (DB25 pin 8) low = RX off, high = RX on
; toggles CONTROL bit 5 low = power off, high = power on
;
AX:	TXM = 0
;
	STAT = CTRL & %00000001		; mask for RX on bit
	if STAT > 0 then AXOF		; jump if bit high
;
	STAT=	CTRL | %00100001		; set bits 0 and 5
	CTRL = STAT				; save status
	pins = CTRL				; turn radio ON (bit 0) latch power ON (bit 5)
	high portc 6			; latch control data
	low portc 6				; latch control data
	pins = %00000000			; set lines low
	return				; finished
;
AXOF:	STAT = CTRL & %11011110		; clear bits 0 and 5
	CTRL = STAT				; save status
	pins = CTRL				; turn radio OFF (bit 0) turn power OFF (bit 5)
	high portc 6			; latch control data
	low portc 6				; latch control data
	end					; halt CPU
;
;********************************************************************
;ok		Set the Bandwidth
;********************************************************************
; Toggles CONTROL bit 1 (DB25 pin 1) low=300hz BW, high=3Khz BW
; uses STAT, CTRL, TEMP
; enters with nothing, leaves with nothing
; calls LCD_CMD, LCD_CHR
;
BW:	STAT = CTRL & %00000010		; mask for BW bit
	if STAT > 0 then BWL		; jump if bit high
;
	STAT = CTRL | %00000010		; set BW bit to 1 (wide)
	CTRL = STAT				; save status
;
	CHAR = LCDL3			; set LCD to the end of line 2
	gosub LCD_CMD			; send command
	CHAR = "W"				; write W to LCD display
	gosub LCD_CHAR			; send a character
	goto BWX		
;
BWL:	STAT = CTRL & %00111101		; set BW to zero (narrow)
	CTRL = STAT				; save status
;
	CHAR = LCDL3			; set LCD to the end of line 2
	gosub LCD_CMD			; send command
	CHAR = "N"				; write N to LCD display
	gosub LCD_CHAR			; send a character
;
BWX:	pins = CTRL				; load control port
	high portc 6			; latch control data
	low portc 6				; latch control data
	pins = %00000000			; set lines low
	return				; finished
;
;********************************************************************
;ok	check synth lock line	
;********************************************************************
; read SYNTH LOCK line and display "*" if high
; uses STAT, FCNT, CHAR
; calls LCD_CMD, LCD_CHAR
;
SLK:	if FCNT < 7 then SLKX		; exit if currently inputing the frequency
;
	readadc 6,STAT			; read the SYNTH LOCK line
;
	if STAT > 120 then SLKH		; jump if higher than 120
	if STAT <  70 then SLKL		; jump if lower than 70
	goto SLKX				; exit if between 70 and 120
;
SLKH:	CHAR = LCDL4			; set LCD to the "end but one" of line 2
	gosub LCD_CMD			; send command
	CHAR = "*"				; write * to LCD display(means transmitter on line)
	gosub LCD_CHAR			; send a character
	goto SLKX
;
SLKL:	CHAR = LCDL4			; set LCD to the "end but one" of line 2
	gosub LCD_CMD			; send command
	CHAR = " "				; write a blank to LCD display (means not on line)
	gosub LCD_CHAR			; send a character
;
SLKX:	return				; finished
;
;********************************************************************
;####################################################################
;ok		Check the keyboard
;####################################################################
;********************************************************************
; uses ROW, COL, KEY, KPTR, KLR0
; calls nothing
; if entry with ROW = $FF, it exits with KEY = $FF
; if entry with ROW and COL values, it exits with KEY = an ASCII character
;					
KYBD_CHK:						; CHECK FOR KEYS
	if ROW = $FF then KYBD_CHKX		; jump if no key found
	KPTR = ROW*12 + KLR0 + COL		; point to character (multiply first)
	read KPTR,KEY				; get the character
	goto KYBD_CHKX1				; jump to exit
KYBD_CHKX:
	KEY = $FF					; set no character found
KYBD_CHKX1:
	return					; finished
;
;********************************************************************
;ok		Scan the keyboard
;********************************************************************
; uses ROW,COL,CNT
; calls nothing
; if no key found, it exits with ROW = $FF
; if key found, it exits with ROW = 0 to 4, and COL = 0 to 11
;					
KYBD_SCAN:					; SCAN THE KEYBOARD
	ROW = $FF				; set ROW to hexFF (it means no key)
	for CNT = 0 to 4			; scan 5 rows
	low portc CNT			; set row low
	if pin0 = 0 then KC0		; Jump if key DOWN in column 0
	if pin1 = 0 then KC1		; Jump if key DOWN in column 1
	if pin2 = 0 then KC2		; Jump if key DOWN in column 2
	if pin3 = 0 then KC3		; Jump if key DOWN in column 3
	if pin4 = 0 then KC4		; Jump if key DOWN in column 4
	if pin5 = 0 then KC5		; Jump if key DOWN in column 5
	if pin6 = 0 then KC6		; Jump if key DOWN in column 6
	if pin7 = 0 then KC7		; Jump if key DOWN in column 7
	if portA pin0 = 0 then KC8	; Jump if key DOWN in column 8
	if portA pin1 = 0 then KC9	; Jump if key DOWN in column 9
	if portA pin2 = 0 then KC10	; Jump if key DOWN in column 10
	if portA pin3 = 0 then KC11	; Jump if key DOWN in column 11
KYS8:	high portc CNT			; set row high
	next CNT				; do next row
	return				; finished
;
KC0:	COL = 0				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC1:	COL = 1				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC2:	COL = 2				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC3:	COL = 3				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC4:	COL = 4				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC5:	COL = 5				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC6:	COL = 6				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC7:	COL = 7				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key			
;
KC8:	COL = 8				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC9:	COL = 9				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC10:	COL = 10				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
KC11:	COL = 11				; save COL
	ROW = CNT				; save ROW
	goto KYS8				; do next key
;
;********************************************************************
;ok		Initialise variables
;********************************************************************
; uses no variables
; calls nothing
; port b output is always low, changes with valid data, then back to all low
; port c bits 0,1,2,3,4 always high, low pulses when scanning keyboard
; port c bits 5 and 6 always low, high pulse to latch data in FREQ and CONTROL latches
; port c bits 7 always high, low pulse to latch data in LCD 
;
INIT:						; INITIALISE
	TXM = 0				; set to receive mode
;
	pinsc = %10011111			; set port c data bits all high
	dirsc = %11111111			; set port c to 8 outputs
;
	pins  = FSETI			; initialise FREQ port
	high portc 5			; latch FREQ port
	low portc  5			; latch FREQ port
;
	pins  = CTRLI			; initialise CONTROL port 
	high portc 6			; latch CONTROL port
	low portc  6			; latch CONTROL port
;
	for FCNT = 0 to 6			; load the default frequency to the tx buffer
	FPTR = TFQI + FCNT		; point to the frequency buffer
	read FPTR,CHAR			; get digit
	FPTR = TXFQB + FCNT		; point to the tx frequency buffer
	poke FPTR,CHAR			; save digit
	next FCNT				; continue
;
	for FCNT = 0 to 6			; load the default frequency to the rx buffer
	FPTR = RFQI + FCNT		; point to the frequency buffer
	read FPTR,CHAR			; get digit
	FPTR = RXFQB + FCNT		; point to the receive frequency buffer
	poke FPTR,CHAR			; save digit
	next FCNT				; continue
;
	FCNT = 0				; set digit count to zero
	pins = %00000000			; set lines low
	return				; finished
;
;********************************************************************
;ok		Initialise the LCD display
;********************************************************************
; uses no variables
; calls nothing
;
LCD_INIT:					; INITIALISE THE LCD
	pause 100				; wait 100ms for LCD to reset
; 
	pins = $03				; send $03 three times
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 10				; wait 10ms
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
;
	pins = $02				; set to 4 bit data mode
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
;
	pins = $02				; high nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
	pins = $08				; set 2 character lines, 5x7 pixels
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
;
	pins = $00				; high nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
	pins = $0C				; display ON, cursor OFF, cursor STEADY
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
;
	pins = $00				; high nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
	pins = $06				; cursor to INCREMENT, cursor to MOVE
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
;
LCD_CLEAR:
	pins = $00				; high nibble 
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 1				; wait 1ms
	pins = $01				; send CLEAR command
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 10				; wait 10ms
;
	pins = %00000000			; set lines low
	return				; finished
;
;********************************************************************
;ok		Write a character to the LCD display
;********************************************************************
; enters with CHAR = character to be written to the LCD display
; uses CHAR, NIBH, NIBL, DAT
; calls nothing
;
LCD_CHAR:					; SEND A CHARACTER (CHAR)
	pins = CHAR & NIBH / 16 | DAT	; output the high nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 10				; wait 8ms for LCD
;
	pins = CHAR & NIBL  | DAT	; output the low nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 10				; wait 8ms for LCD
;
	pins = %00000000			; set lines low
	return				; finished
;
;********************************************************************
;ok		Write the Title
;********************************************************************
; uses KPTR, LEN, CHAR
; calls LCD_CHAR
;
TITLE:					; WRITE A STRING TO THE LCD DISPLAY
	for KPTR = 0 to LEN		; loop for the string length
	read KPTR,CHAR			; get the character
	gosub LCD_CHAR			; write the character
	next KPTR				; inc the pointer and loop
	return				; finished
;
;********************************************************************
;ok		Write a command to the LCD display
;********************************************************************
; enters with CHAR = command to be written to the LCD display
; uses CHAR, NIBH, NIBL, CMD
; calls nothing
;
LCD_CMD:					; SEND A CHARACTER (CHAR)
	pins = CHAR & NIBH / 16 | CMD	; output the high nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
;
	pins = CHAR & NIBL  | CMD	; output the low nibble
	low portc 7				; latch the data
	high portc 7			; raise the enable line
	pause 8				; wait 8ms for LCD
;
	pins = %00000000			; set lines low
	return				; finished
;
;********************************************************************
;ok		Clear the LCD RX frequency display
;********************************************************************
; uses CHAR
; calls LCD_FQ, LCD_CMD, LCD_CHAR
;
LCD_RFQ:
	CHAR = LCDL1				; set LCD to line 1
	gosub LCD_FQ				; clear
	CHAR = LCDL1				; set LCD to line 1
	gosub LCD_CMD				; send command
	CHAR = "R"					; Write R to LCD display
	gosub LCD_CHAR				; send a character
	CHAR = " "					; load a blank
	gosub LCD_CHAR				; send a character	
	return					; finished
;
;********************************************************************
;ok		Clear the LCD TX frequency display
;********************************************************************
; uses CHAR
; calls LCD_FQ, LCD_CMD, LCD_CHAR
;
LCD_TFQ:
	CHAR = LCDL2				; set LCD to line 2
	gosub LCD_FQ				; clear
	CHAR = LCDL2				; set LCD to line 2
	gosub LCD_CMD				; send command
	CHAR = "T"					; Write T to LCD display
	gosub LCD_CHAR				; send a character
	CHAR = " "					; load a blank
	gosub LCD_CHAR				; send a character
	return
;
;********************************************************************
;ok		Clear the LCD frequency display
;********************************************************************
; uses CHAR, CNT
; calls LCD_CMD, LCD_CHAR
; at entry, CHAR contains a pointer to line 1 or line 2
;	
LCD_FQ:
	gosub LCD_CMD				; send command
	CHAR = " "					; load a blank	
	for CNT = 0 to 3				; Clear the start of the LCD display
	gosub LCD_CHAR				; send a character
	next CNT					; continue
;
	CHAR = "."					; load a decimal point	
	gosub LCD_CHAR				; send a character
;
	CHAR = " "					; load a blank	
	for CNT = 4 to 8				; Clear the rest of the LCD display
	gosub LCD_CHAR				; send a character
	next CNT					; continue
;
	CHAR = "0"					; Write 0 to LCD display
	gosub LCD_CHAR				; send a character
	return
;
;********************************************************************
;ok		DIAGNOSTIC: toggle pin 8 on the DB25, every second
;********************************************************************
; uses no variables
; calls AX
;
;DIAG2: 					; TEST ROUTINE 2
;	gosub AX				; radio ON
;	pause 1000				; wait 1000 ms
;	gosub AX				; radio OFF
;	pause 1000				; wait 1000 ms
;	goto DIAG2
;	return				; finished
;
;********************************************************************
;ok		DIAGNOSTIC: toggle PICAXE port C pin 5,6,7, every 100ms
;********************************************************************
; uses no variables
; calls nothing
;
;DIAG3: 					; TEST ROUTINE 1
;	low portc 5				; make pin 5 low
;	high portc 5			; make pin 5 high
;	pause 100				; wait 100 ms
;
;	low portc 6				; make pin 6 low
;	high portc 6			; make pin 6 high
;	pause 100				; wait 100 ms
;	low portc 6				; make pin 6 low
;	high portc 6			; make pin 6 high
;	pause 100				; wait 100 ms
;
;	low portc 7				; make pin 7 low
;	high portc 7			; make pin 7 high
;	pause 100				; wait 100 ms
;	low portc 7				; make pin 7 low
;	high portc 7			; make pin 7 high
;	pause 100				; wait 100 ms
;	low portc 7				; make pin 7 low
;	high portc 7			; make pin 7 high
;	pause 100				; wait 100 ms
;
;	pause 100				; wait 100 ms
;	return				; finished
;
;********************************************************************