Here's a quick tour:

1. Stamp Pin Map. This section establishes the pin #'s for the various input/output
lines. You probably won't have to make any changes here, but if you do, you won't
have to hunt through the program looking for references to the pin you need to change.

2. Band Names. Bands is a symbol used by the program to locate text to be displayed
on the LCD for the each of the bands. The names are fixed-width and arranged in the
same order as the FT990's band data encoding. That is, when the radio is tuned to the
160 meter band, the band data encoding is 1, so 160 meters is listed first (0 only
appears when the radio is off). The FT990 is an HF radio and all the HF bands are
listed, but for completeness I also listed other values that could appear on the band
data jack. I labeled them 'UNK' but I assume they have some meaning for VHF or UHF radios.

MaxBands is used as array dimensions later to remember the last antenna and amplifier
segment used for each band. It is set to 9 to save Stamp memory space.

3. Antenna Names and Numbers. Antennas is a symbol indicating the start of the list of
antennas. You'll want to customize this to match your setup. Each antenna is two data
items -- the physical antenna number of the antenna on the switch, and a fixed-width
name to display on the LCD when that antenna is selected. LIST_END is an important symbol
-- it is a 'marker' used by the antenna cycling routines to 'wrap around' from the last
antenna to the first when you press the up/down buttons.

4. Band to Antenna Map. This section (BandAnts) maps antennas to the bands they work on.
For each pair, the first number is the band number (from the Bands list above) and the
second is the antenna number. The controller will prevent transmission to an antenna not
defined for the current band. Change this to match your station.

The structure of the program itself is pretty simple. When the Stamp is powered up, it
starts executing from the top, which begins with a pause to let the LCD settle. All
variables start off initialized to 0 so the current antenna will be 0. The current band
comes from the band data jack of the radio so the first thing that needs to happen is
process this 'band change' at RadioBandChanged. This selects an appropriate antenna for
this band (either by selecting the last one we used or picking the first one in the
BandAnts list for this band. Once selected, we tell the antenna switch about it and
update the display.

Then we drop into the loop, and the Stamp is doomed to repeat forever. It constantly
cycles looking for changes in its inputs:

1. UP or DOWN buttons cause the antenna to change. These cycle through the Antennas
list sending change commands to the switch and enabling or disabling the transmitter
according to the BandAnts map.

2. Band data change to detect band QSYs on the radio.

3. Each time the LCD is updated, its backlight comes on and then goes out after a
short delay. You can adjust the length of the delay by changing the value of the
constant BkLitTime. Each increment of 25 is roughly a second but depends on the
processing in the loop.

4. Poll the amplifier serial line to see if it is announcing anything. The Stamp's
serial input command allows for a time out (50 milliseconds in this case) so it is
ok if the amplifier is not on, we'll just skip over any amplifier processing. If a
message does come in, it is parsed and checked against the current antenna. Antenna
change commands may be sent to the amplifier if need be at this point.

Note that if you customize this code you will want to keep the processing inside the
loop lightweight, because if too much is going on, you might miss a message from the
amplifier. The Stamp does not do any buffering, so if it is not waiting for a message,
it will be lost.

'{ $STAMP BS2 }

' Automatic Antenna switch

' STAMP PIN MAP:
' Symbol		PIN	 I/O	Purpose
RadBand	VAR	INA	' I	(pins 0-3) Band-data (radio) ABCD
TxInhPin	CON	4	' O	TX-inhibit line - slaved from XmitOk
UpBtnPin	CON	6	' O	UP button
DownBtnPin	CON	7	' O	DOWN button
LCD_PIN	CON	11	' O	LCD communications
LCD_BkLit	CON	12	' O	Backlight control
AmpSerIn	CON	13	' I	Serial inbound comms from amplifier
AmpSerOut	CON	14	' O	Serial outbound comms to amplifier
AntSerOut	CON	15	' O	Serial outbound comms to antenna switch

' Define bands & antennas. 

' Band names - define an 'array' of band names, indexed starting
' at 1. Band name strings must all be the same length.
' There is no 0 - it means radio is off!
Bands		DATA	"160m"		' Band #1...
Band1		DATA	" 80m"
		DATA	" 40m"
		DATA	" 30m"
		DATA	" 20m"
		DATA	" 17m"
		DATA	" 15m"
		DATA	" 12m"
		DATA	" 10m"		' Last band we care about
		DATA	" UNK"		' These are bands not returned
		DATA	" UNK"		' By the FT990.
		DATA	" UNK"		' VHF/UHF bands??
		DATA	"  LF"	
		DATA	"  AM"
MaxBands	CON	9		' We care about band #1-10
					' No 15!
BandSize	CON	Band1 - Bands	' Size of each band entry

LIST_END	CON	255		' Flag constant for begin/end of lists

' LIMIT: There shouldn't be more than 15 antennas - the list of memorized
' antennas is a nibble array (4 bits).
' PLUS, the ACOM 2000S/2000A only understand 10!
' Antenna name sizes all have to be the same!
		DATA	LIST_END	' Beginning of list
Antennas	DATA	1,"N1217"
Antenna1	DATA	3,"XM240"
		DATA	4,"C3-EU"
LastAnt	DATA	5,"C31XR"	' Last one always needs LastAnt!
		DATA	LIST_END	' End of list
AntSize	CON	Antenna1 - Antennas	' Size of each antenna entry

' Map bands to antennas. These are pairs: Band,Ant#
' Bands that are missing are not supported. 
' List order is increasing.
' Band#LIST_END = end of list
BandAnts	DATA	3,3		' 40m on XM240
		DATA	5,4, 5,5	' 20m on C3-EU & C31XR
		DATA	6,1		' 17m on N1217
		DATA	7,4, 7,5	' 15m on C3-EU & C31XR
		DATA	8,1		' 12m on N1217
		DATA	9,4, 9,5	' 10m on C3-EU & C31XR
		DATA	LIST_END	' End of list, beginning of next list
BandAntsSize	CON	2		' Size of each entry

' Antenna/Band state
CurBand	VAR	NIB	' Currently selected band we're on
CurAnt		VAR	NIB	' Current antenna we're using
XmitOk		VAR	BIT	' Flag - ok to xmit on this antenna?
ChgDir		VAR	BIT	' Direction something is changing:
				' 1= forward, 0=backward
LastAnts	VAR	NIB(MaxBands) ' List of last antennas used by band
LastSegs	VAR	BYTE(MaxBands) ' List of last amp segments used by band

' Button-Support variables
BtnPin		VAR	NIB	' Pin # for button to examine
BtnPressed	VAR	BIT	' T/F: Button pressed
BtnWork	VAR	BYTE	' BUTTON working variable

' Amp/Antenna switch support
AcomNetAmp	CON	$41	' ACOM-Net amplifier address
AcomNetAnt	CON	$51	' ACOM-Net selector address
AcomNetUs	CON	$71	' ACOM-Net 'PC controller' address (us)
N1200		CON	813 	' 1200 baud, no parity, 8 bits, 1 stop, TRUE
				' 17197 works for direct (non-driven)
AmpSegText	VAR	BYTE(2) ' 'Encrypted' amplifier segment
AmpSegAnt	VAR	NIB	' Current antenna for a segment
Segment	VAR	BYTE	' Current amp segment
SegNibHi	VAR	Segment.HIGHNIB
SegNibLo	VAR	Segment.LOWNIB

' LCD parameters
BkLitTimer	VAR	BYTE	' Countdown for LCD backlight
BkLitTime	CON	100	' 'Countdown' starter (~4 seconds)

' General-purpose; clobbered by many subs :)
Addr		VAR	WORD	' EEPROM address for READing data.
AddrByte	VAR	BYTE	' Value read from Addr
AddrLookup	VAR	NIB	' Something to look for
AddrChgDir	VAR	BIT	' Direction to move for NextEntry
AddrDelta	VAR	NIB	' Size of each entry for NextEntry
bGenFlag	VAR	BIT	' General true/false flag

' Pause to let LCD start up (1s total)
PAUSE 1000

' All pins default to input - set some to output
OUTPUT TxInhPin

' CurAnt starts out at 0
' Is the radio turned on? If not, RadBand will also be 0
RadioBandChanged:
	' The radio was tuned to a different band!
	' Do something for CurBand = 0? Radio was turned off!
	CurBand = RadBand
	GOSUB AntennaForBand

FinishAntOrBandChange:
	GOSUB SendAntCmd
	GOSUB UpdateDisplay

' Loop forever...
Loop:
	' Check 'UP' button:
	BtnPin = UpBtnPin
	GOSUB CheckButton
	IF BtnPressed THEN UpButtonPressed

	' Check 'DOWN' button:
	BtnPin = DownBtnPin
	GOSUB CheckButton
	IF BtnPressed THEN DownButtonPressed

	' Band change?
	IF (RadBand <> CurBand) THEN RadioBandChanged

	' Backlight need attention?
	GOSUB BackLightCountdown

	' Skip all this if the radio is off - it is unlikley the
	' amp would be sending us any info at this point, but it
	' would only be messed up by a bogus CurBand
	IF (CurBand = 0) THEN Loop

	' Check to see if the amp is broadcasting a 'W1' to announce
	' a segment change. Back to Loop if we don't see it.
	' Try for 50ms - wait too long and the buttons are sluggish.
	' Wait to little and we miss it!
	SERIN AmpSerIn, N1200, 50, Loop, [WAIT(AcomNetAmp), WAIT("W1"), STR AmpSegText\2, DEC1 AmpSegAnt]
	' If we got here there was something to see!
	' Decode the current segment
	GOSUB AmpSegTextToSegment
	' Is this segment sane for our band?
	GOSUB CheckAmpSegmentForBand
	IF (bGenFlag = 0) THEN SkipSaveSegmentForBand
	' Save this segment for this band
	LastSegs(CurBand - 1) = Segment

SkipSaveSegmentForBand:
	' Is the amp using the antenna we want?
	IF (AmpSegAnt = CurAnt) THEN Loop
	' Need to send antenna change command
	GOSUB SendAmpCmd

	' Back to the loop...
	GOTO Loop

UpButtonPressed:
	' UP button pressed!
	ChgDir = 1
	GOTO FinishButtonPress

DownButtonPressed:
	' DOWN button pressed!
	ChgDir = 0

FinishButtonPress:
	' Validate new antenna
	GOSUB ChangeAntenna
	GOTO FinishAntOrBandChange


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
ChangeAntenna:
	' Move CurAnt one slot in (ChgDir) direction.
	' Make sure it is valid by:
	'	Wrapping around if we go below or above the list
	'	Move up or down if we select a 'hole'
	' Set XmitOk according to the new antenna's relationship to 
	' CurBand.
	' IN Parameters:
	'	ChgDir = Direction to change antenna (0=down, 1=up).
	'	CurAnt = Currently selected antenna.
	'	CurBand = Currently selected band.
	' OUT Parameters:
	'	CurAnt = Newly selected antenna, corrected.
	'	XmitOk = 0/1 - ok to xmit on this antenna on this band?
	' USES Variables:
	'	Addr = Assorted EEPROM addresses.
	'	AddrByte = Value read from Addr.
	'	AddrLookup = Antenna to search for in Antennas list
	'	AddrDelta = AntSize

	' Get entry for CurAnt - if CurAnt is 0, start at the first one!
	Addr = Antennas
	IF (CurAnt = 0) THEN ChangeAntenna_Move
	AddrLookup = CurAnt
	AddrDelta = AntSize
	GOSUB LookupEntry
	' Addr shouldn't ever be -1 for CurAnt!

ChangeAntenna_Move:
	' Move to the next entry in the right direction
	AddrChgDir = ChgDir
	GOSUB NextEntry
	IF (Addr <> -1) THEN ChangeAntenna_GotIt

	' We fell off the list - need to 'wrap'
	' Which direction are we changing?
	IF ChgDir THEN ChangeAntenna_WrapToFirst

	' Get the last entry
	Addr = LastAnt
	GOTO ChangeAntenna_GotIt

ChangeAntenna_WrapToFirst:
	' Get the first entry
	Addr = Antennas

ChangeAntenna_GotIt:
	' Addr points to the antenna entry we want!
	READ Addr, CurAnt

	' Look for this antenna in BandAnts to see if our band is listed
	Addr = BandAnts
	AddrLookup = CurBand
	AddrDelta = BandAntsSize
	GOSUB LookupEntry
	' Addr shouldn't ever be -1 for CurBand in BandAnts!
	' Assume combination is no good
	XmitOk = 0

	' Loop looking for this antenna
ChangeAntenna_Loop:
	READ Addr + 1, AddrByte
	IF (AddrByte = CurAnt) THEN ChangeAntenna_XmitOk
	' Next entry - still on our band?
	GOSUB NextEntry	' AddrChgDir set by LookupEntry!
	IF (Addr = -1) THEN ChangeAntenna_Exit
	READ Addr, AddrByte
	IF AddrByte = CurBand THEN ChangeAntenna_Loop
	' Ran out of our band!

ChangeAntenna_Exit:
	' Return w/XmitOK = 0
	RETURN

ChangeAntenna_XmitOk:
	' Band and antenna are ok! Remember this as the last one...
	XmitOk = 1
	LastAnts(CurBand - 1) = CurAnt
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
SendAntCmd:
	' Send 'change antenna' command to selector.
	' Set or clear transmit-inhibit line according to XmitOk flag.
	' The 'tx-inhibit' signals from the switch and/or amplifier are
	' connected to the emitter of an NPN transistor. LINEAR or
	' PIN 8 from the radio's band-data plug is connected to the
	' collector. Pin TxInhPin is connected to the base.
	' When TxInhPin is high, whatever setting the amp/switch have
	' is passed onto the radio. This means _we_ think the antenna
	' is ok, so any other reason NOT to transmit comes from them.
	' If TxInhPin is low, we don't want the radio to transmit no
	' matter what the amp/switch think, so we block their signal.
	' Once we tell the switch about it, see if we need to do the
	' same with the amplifier.
	' IN Parameters:
	'	CurAnt = Antenna # to set.
	'	AntSerOut = Constant pin# to communicate w/switch
	'	AcomNetAnt = Constant 'network' address of antenna switch
	'	AcomNetUs = Constant 'network' address of 'us'
	'	XmitOk = Flag for xmit inhibit line.
	'	TxInhPin = Constant pin# to enable/disable tx
	' OUT Parameters:
	'	None.
	' USES Variables:
	'	None.

	SEROUT AntSerOut, N1200, [AcomNetAnt, AcomNetUs, "W3", $30 + CurAnt, 0]
	OUTS.LOWBIT(TxInhPin) = XmitOk
	' Fall thru to send amp command if we need to

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
SendAmpCmdIfNeeded:
	' We changed antennas. See if the amplifier is in a segment in
	' our band, and if so, change its antenna. Otherwise, we'll get
	' the chance to change the antenna the next time it 'autotunes'.
	' IN Parameters:
	'	CurAnt = Antenna # to set.
	'	AmpSerOut = Constant pin# to communicate out to amp
	'	AmpSerIn = Constant pin# to communicate in from amp
	'	AcomNetAmp = Constant 'network' address of amplifier
	'	AcomNetUs = Constant 'network' address of 'us'
	' OUT Parameters:
	'	None.
	' USES Variables:
	'	AddrByte = Lookup band segment

	' Ask the amp for the current seg#
	SEROUT AmpSerOut, N1200, [AcomNetAmp, AcomNetUs, "W7", 0]
	' Wait 200ms for the answer. If we don't get one, no sense
	' in doing any more. Answer will look like 'XYW1ssaub' where:
	'	X = Our network address
	'	Y = Amp's network address
	'	ss = Funky seg #
	'	a = Antenna number
	'	u = 0 for DEF, 1 for USR
	'	b = 'SubBand'
	' We really only care about the 'ss' & 'a' so skip the rest
	SERIN AmpSerIn, N1200, 200, SendAmpCmdIfNeeded_NotNeeded, [WAIT("W1"), STR AmpSegText\2, DEC1 AmpSegAnt]
	' Decode the segment # & see if it makes sense for this band
	GOSUB AmpSegTextToSegment
	GOSUB CheckAmpSegmentForBand
	IF (bGenFlag) THEN SendAmpCmdIfNeeded_AmpSegmentOk
	' The segment is outside of the band
	' Have we saved a segment for this band before?
	' If so, go to it
	IF (LastSegs(CurBand - 1) <> 0) THEN SendAmpCmd	
	' We are outside the band, and we don't have a segment to 
	' recall, so don't do anything.
	GOTO SendAmpCmdIfNeeded_NotNeeded

SendAmpCmdIfNeeded_AmpSegmentOk:
	' Ok, we're in the band. Now see if the antennas differ
	IF (CurAnt <> AmpSegAnt) THEN SendAmpCmd

SendAmpCmdIfNeeded_NotNeeded:
	' If we get here no command is needed
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
SendAmpCmd:
	' Send 'change antenna' command(s) to amplifier.
	' IN Parameters:
	'	CurAnt = Antenna # to set.
	'	AmpSerOut = Constant pin# to communicate out to w/amp
	'	AcomNetAmp = Constant 'network' address of amplifier
	'	AcomNetUs = Constant 'network' address of 'us'
	' OUT Parameters:
	'	None.
	' USES Variables:
	'	None.

	' Bail if CurBand is 0 or we can't xmit
	IF (CurBand = 0) THEN SendAmpCmd_Done
	IF (XmitOk = 0) THEN SendAmpCmd_Done

	' Are we sending a segment too?
	IF (LastSegs(CurBand - 1) <> 0) THEN SendAmpCmd_SegmentCmd

	' This the same as the command sent to the switch!
	SEROUT AmpSerOut, N1200, [AcomNetAmp, AcomNetUs, "W3", $30 + CurAnt, 0]
	GOTO SendAmpCmd_Done

SendAmpCmd_SegmentCmd:
	' Send segment with antenna
	Segment = LastSegs(CurBand - 1)
	GOSUB SegmentToAmpSegText
	SEROUT AmpSerOut, N1200, [AcomNetAmp, AcomNetUs, "W1", STR AmpSegText\2, $30 + CurAnt, 0]

SendAmpCmd_Done:
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
CheckAmpSegmentForBand:
	' Check to see if (Segment) makes sense for CurBand.
	' Return 1 or 0 in bGenFlag
	' IN Parameters:
	'	Segment = Current amp segment #
	'	CurBand = Current radio band
	' OUT Parameters:
	'	bGenFlag = 1=Segment sane
	' USES Variables:
	'	AddrByte = Lookup band segment
	bGenFlag = 0

	' Check the low-end of our current segment
	AddrByte = 0
	' Bands:	    160 80 40  30  20  17  15  12  10
	LOOKUP CurBand, [0,2,43,93,123,163,193,213,231,243], AddrByte
	IF (AddrByte = 0) THEN CheckAmpSegmentForBand_Return
	' Are we in the ballpark?
	IF (Segment < AddrByte) THEN CheckAmpSegmentForBand_Return

	' Ok so far - Check the high-end
	AddrByte = 0
	' Bands:	    160 80 40  30  20  17  15  12  10
	LOOKUP CurBand, [0,9,52,95,124,166,194,215,231,249], AddrByte 
	IF (Segment > AddrByte) THEN CheckAmpSegmentForBand_Return

	' Segment checks out - ok for this band!
	bGenFlag = 1

CheckAmpSegmentForBand_Return:
	RETURN

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
AmpSegTextToSegment:
	' Translate 2-byte AmpSegText read from amplifier into Segment
	' byte.
	' IN Parameters:
	'	AmpSegText = 2-byte segment text read from amplifier.
	' OUT Parameters:
	'	Segment = 1-byte segment number.
	' USES Variables:
	'	None.
	SegNibHi = AmpSegText(0) - $30
	SegNibLo = AmpSegText(1) - $30
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
SegmentToAmpSegText:
	' Translate Segment byte into 2-byte AmpSegText ready to send to
	' amplifier.
	' IN Parameters:
	'	Segment = 1-byte segment number.
	' OUT Parameters:
	'	AmpSegText = 2-byte segment text read from amplifier.
	' USES Variables:
	'	None.
	AmpSegText(0) = SegNibHi + $30
	AmpSegText(1) = SegNibLo + $30
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
UpdateDisplay:
	' Update the LCD with the current information
	' IN Parameters:
	'	None.
	' OUT Parameters:
	'	None.
	' USES Variables:
	'	Addr = Assorted EEPROM addresses.
	'	AddrByte = Value read from Addr.
	'	AddrLookup = Value to find in list at Addr.
	'	AddrDelta = Size of entries in lookup lists

	' LCD constants
	N9600		CON	$4054
	LCD_IPfx	CON	254	' Special command prefix
	LCD_CLR	CON	1	' Clear screen
	LCD_CUR_INV	CON	12	' Invisible cursor
	LCD_CUR_BLK	CON	13	' Blinking cursor
	LCD_ARROW	CON	126	' Arrow symbol
	LCD_1ST_LINE	CON	128	' Addr of first line
	LCD_2ND_LINE	CON	192	' Addr of 2nd line

	' Clear screen
	SEROUT LCD_PIN, N9600, [LCD_IPfx, LCD_CLR]
	PAUSE 1	' Clear screen needs a pause
	' Clear cursor
	SEROUT LCD_PIN, N9600, [LCD_IPfx, LCD_CUR_INV]
	' Turn on backlight
	GOSUB BackLightOn

	' Is the radio on?
	IF (CurBand <> 0) THEN UpdateDisplay_Band
	' Radio is OFF!
	' Move to line 2 for the message...
	SEROUT LCD_PIN, N9600, [LCD_IPfx, LCD_2ND_LINE, "Radio is OFF"]
	' Back to line 1 for the band
	SEROUT LCD_PIN, N9600, [LCD_IPfx, LCD_1ST_LINE, "NONE"]
	GOTO UpdateDisplay_Sep

UpdateDisplay_Band:
	' Display Band - order of math is important...
	Addr = (CurBand - 1) * BandSize + Bands
	AddrDelta = BandSize
	GOSUB TextToLCD

UpdateDisplay_Sep:
	' Display seperator
	SEROUT LCD_PIN, N9600, [" ", LCD_ARROW, " "]

UpdateDisplay_Antenna:
	' Display Antenna - any set?
	IF (CurAnt <> 0) THEN UpdateDisplay_DispAnt
	SEROUT LCD_PIN, N9600, ["None"]
	GOTO UpdateDisplay_XmitFlag

UpdateDisplay_DispAnt:
	SEROUT LCD_PIN, N9600, [DEC CurAnt, "="]
	Addr = Antennas
	AddrLookup = CurAnt
	AddrDelta = AntSize
	GOSUB LookupEntry
	' Check for Addr = -1?
	Addr = Addr + 1
	AddrDelta = AntSize - 1
	GOSUB TextToLCD

UpdateDisplay_XmitFlag:
	' Do we need the blinking cursor for no xmit?
	IF XmitOk THEN UpdateDisplay_Exit	
	' Put blinking cursor on top of arrow
	SEROUT LCD_PIN, N9600, [LCD_IPfx, LCD_1ST_LINE + BandSize + 1, LCD_IPfx, LCD_CUR_BLK]

UpdateDisplay_Exit:
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
BackLightOn:
	' Turn on the LCD backlight and start the 'timer'
	' IN Parameters:
	'	None.
	' OUT Parameters:
	'	BkLitTimer set to begin countdown
	' USES Variables:
	'	None

	HIGH LCD_BkLit
	BkLitTimer = BkLitTime
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
BackLightCountdown:
	' See if the backlight needs to be turned off
	' IN Parameters:
	'	BkLitTimer - countdown. Backlight is on if this is > 0.
	' OUT Parameters:
	'	None
	' USES Variables:
	'	BkLitTimer

	' Is the light even on?
	IF (BkLitTimer = 0) THEN BackLightCountdown_Exit

	' Decrement and check - time to turn it off?
	BkLitTimer = BkLitTimer - 1
	IF (BkLitTimer > 0) THEN BackLightCountdown_Exit
	LOW LCD_BkLit

BackLightCountdown_Exit:
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
TextToLCD:
	' Given text at Addr, send it to the LCD until 0 is found or
	' we've displayed AddrDelta characters, whichever comes first.
	' IN Parameters:
	'	Addr = EEPROM address of beginning of text.
	'	AddrDelta = # of characters to display. CLOBBERED!
	' OUT Parameters:
	'	None.
	' USES Variables:
	'	Addr
	'	AddrByte = Value read from EEPROM.

TextToLCD_Loop:
	READ Addr, AddrByte
	' End of text?
	IF (AddrByte = 0) THEN TextToLCD_Done
	' No - send char
	SEROUT LCD_PIN, N9600, [AddrByte]
	Addr = Addr + 1
	AddrDelta = AddrDelta - 1
	IF (AddrDelta > 0) THEN TextToLCD_Loop

TextToLCD_Done:
	' All done!
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
AntennaForBand:
	' Given CurBand, lookup the last used antenna for this
	' band. Return it in CurAnt.
	' IN Parameters:
	'	CurBand = Band for which to look up antenna.
	' OUT Parameters:
	'	CurAnt = Last antenna used on CurBand.
	' USES Variables:
	'	Addr = EEPROM address.
	'	AddrByte = Value read from EEPROM.

	Addr = BandAnts
	' Assume failure
	XmitOk = 0

	' Look for first ocurrance of CurBand.
AntennaForBand_Loop
	READ Addr, AddrByte
	' End of list? If so, return unchanged
	IF (AddrByte = LIST_END) THEN AntennaForBand_Return
	IF (AddrByte = CurBand) THEN AntennaForBand_FoundFirst
	' Not found yet - bump to next Band,Ant pair
	Addr = Addr + BandAntsSize
	GOTO AntennaForBand_Loop

AntennaForBand_FoundFirst:
	' Found the first match for this band
	XmitOk = 1
	' Have we remembered an antenna on this band?
	IF (LastAnts(CurBand - 1) = 0) THEN AntennaForBand_UseFirst
	' We've remembered one - use it!
	CurAnt = LastAnts(CurBand - 1)
	RETURN

AntennaForBand_UseFirst:
	' Use Addr's antenna - bump one to look at antenna#
	Addr = Addr + 1
	READ Addr, CurAnt
	' Remember it!
	LastAnts(CurBand - 1) = CurAnt

AntennaForBand_Return:
	' Return CurAnt to caller
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
NextEntry:
	' Addr points to an entry in a list like this:
	'	#,"text"
	'	...
	'	LIST_END
	' AddrChgDir is the direction to go to find the next entry.
	' If we go off the end of the list, Addr will be -1.
	' Otherwise, it will point to the next entry in that direction.
	' IN Parameters:
	'	Addr = Address to move from.
	'	AddrChgDir = Direction to move (1=UP, 0=DOWN).
	'	AddrDelta = Size of each entry
	' OUT Parameters:
	'	Addr = Address of next # or -1 if we fell off the list.
	' USES Variables:
	'	AddrByte = Value read from Addr.

	' Which direction are we going?
	IF AddrChgDir THEN NextEntry_UP

	' Move DOWN
	' See is the prev spot is LIST_END
	READ Addr - 1, AddrByte
	IF (AddrByte = LIST_END) THEN NextEntry_AtEnd
	' Go ahead and move DOWN
	Addr = Addr - AddrDelta
	RETURN

NextEntry_UP:
	' Move UP
	Addr = Addr + AddrDelta
	' See if we fell off the list
	READ Addr, AddrByte
	IF (AddrByte <> LIST_END) THEN NextEntry_Exit

NextEntry_AtEnd:
	' Flag the end!
	Addr = -1

NextEntry_Exit:
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
LookupEntry:
	' Addr points to the beginning of a list like this:
	'	#,"text"
	'	...
	'	LIST_END
	' AddrLookup is the # to look for. If found, Addr will point to
	' the byte containing # matching AddrLookup. If not, Addr will be
	' -1.
	' IN Parameters:
	'	Addr = EEPROM address to start search.
	'	AddrLookup = # to look for on list.
	'	AddrDelta = Size of each entry
	' OUT Parameters:
	'	Addr = Address of # or -1 if not found.
	' USES Variables:
	'	AddrByte = Value read from Addr.

	' Tell NextEntry which way to move
	AddrChgDir = 1

LookupEntry_Loop:
	READ Addr, AddrByte

	' Found ours?
	IF (AddrByte = AddrLookup) THEN LookupEntry_Found

	' Not this one - Move on to the next entry
	GOSUB NextEntry
	IF (Addr <> -1) THEN LookupEntry_Loop
	' Not found - Fall thru with Addr = -1

LookupEntry_Found:
	RETURN


'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
CheckButton:
	' See if a button was pressed, and if so, loop until it is
	' released so that it is 'one event'. Note that this will
	' consume as much time as it takes for the user to release
	' the button, once pressed.
	' NOTE: This works for 'pull-down' button - 'ON' = 0
	' Because that sort of circuit is recommended in Edwards' book.
	' IN parameters:
	'	BtnPin = Pin# to poll
	' OUT parameters:
	'	BtnPressed = 1 if pressed, 0 otherwise
	' USES Variables:
	'	BtnWork

	BtnWork = 0
	' 'Down' state is 0 (pull-up), debounce but no autorepeat
	BUTTON BtnPin, 0, 255, 0, BtnWork, 1, CheckButton_Pressed
	' Button not pressed
	BtnPressed = 0
	RETURN

CheckButton_Pressed:
	' Button WAS pressed - loop until it is released
	IF INS.LOWBIT(BtnPin) = 0 THEN CheckButton_Pressed

	' Button has been released
	BtnPressed = 1
	RETURN