; gps_lcd.src
;
; DBeals Apr 19, 2004
;
; Receive GPS serial chars, format, send display chars to LCD.
;
;-------------------------------------------------------
; Scenix SX18 processor
; Seetron 2 row by 20 character LCD
; Garmin 25LVC GPS sensor
; (see notes at the end for more device information)
;-------------------------------------------------------
; Port A bit 0 pin ?? Output RS232 serial (TTL level) to LCD
; bit 1 unused
; bit 2 unused
; bit 3 unused
;
; Port B bit 0 pin ?? input RS232 serial (TTL level) from GPS
; bit 1 unused
; bit 2 unused
; bit 3 unused
; bit 4 unused
; bit 5 unused
; bit 6 unused
; bit 7 unused
;-------------------------------------------------------
; data ram:
; 00-07 8 CPU registers
; 08-0F 8 bytes of global RAM
; 10-1F, 30-3F, 50-5F...F0-FF 8 banks of 16 bytes user RAM.
;
; code rom:
; 4 banks of 512 ($200) bytes.
; org $000 = bank 0, $200 = bank 1, $400 = bank2, $600 = bank3
;
;-------------------------------------------------------
device SX18, OSCHS, TURBO, STACKX, OPTIONX
IRC_CAL IRC_FAST
freq 20_000_000
reset start_point
;-------------------------------------------------------
; global variables
org 7 ; (the SX18 can use RAM 7 as global)
RS232out ds 1 ; 7 LCD RS232 out character
RS232in ds 1 ; 8 GPS RS232 in character
timer1 ds 1 ; 9 RS232 loop timer
msgBytes ds 1 ; A counts bytes within GPS message field
bitCount ds 1 ; B LCD display loop
temp ds 1 ; C DDMM decoding (and other places)
pointer1 ds 1 ; D generic RAM pointer
pointer2 ds 1 ; E me too
i ds 1 ; F generic loop counter
; time and latitude characters
org $10
bank_ten = $
latASCII = $10 ; lat: 10 ASCII "03749.2345" 0DDMM.MMMM format
latEnd = $19
timeStart = $1A ; time: 6 characters HHMISS in 24:60:60 format
timeEnd = $1F ;
; longitude, status and altitude chars
org $30
bank_lonstat = $
lonASCII = $30 ; lon: 10 chars "12232.3580" DDDMM.MMMM format
lonEnd = $39
altStart = $3A ; alt: from 0 to 5 chars "122.6" meters
altEnd = $3F ; FIXME - should this be $3E?
statusChar = $3F ; GPS status: one char
; ASCII-binary conversions and multiplier locations
org $50 ;
bank_math = $
multStart = $ ; this needs to precede the four "mult"s
mult0 ds 1 ; 4 byte input to 1 x 4 multiply
mult1 ds 1 ; (also used by subtract routine)
mult2 ds 1
mult3 ds 1
accumStart = $ ; this needs to precede the 4 accums
accum0 ds 1 ; 4 byte output from several math routines
accum1 ds 1
accum2 ds 1
accum3 ds 1
eight ds 1 ; 1 byte input to 1 x 4 multiply routine
counter ds 1 ; "counter" used in the multiply loop
negFlag ds 1 ; set to 1 if subtraction is negative
math0 ds 1 ; spares
math1 ds 1 ;
math2 ds 1 ;
math3 ds 1 ;
; 1 unused byte
; 4 binary 4-byte locations
lonToGoTo = $70 ; 4 bytes: lon to go to, binary
lonAtStart = $74 ; 4 bytes: lon started from, binary
latToGoTo = $78 ; 4 bytes: lat to go to, binary
latAtStart = $7C ; 4 bytes: lat started from, binary
; speed and direction
dirStart = $90 ; dir: 90 - 95 000.0
dirEnd = $95 ; FIXME is 95 or 96 good enuf?
speedStart = $96 ; speed: 96 - 9B 0000.0
speedEnd = $9B ;
; 4? unused bytes in bank $90
; decimal display
org $B0 ; binary to decimal conversion area
bank_toASCII = $
counter2 ds 1
hiBin ds 1
loBin ds 1
hiCmp ds 1
loCmp ds 1
fiveDigits = $ ; here begins 5 decimal digits
digit5 ds 1
digit4 ds 1
digit3 ds 1
digit2 ds 1
digit1 ds 1
; 6 unused bytes
org $D0 ; unused space for 16 vars
; last bank has assorted stuff - timer vars, GPS msg counters, etc.
org $F0
bank_assorted = $ ; F0
timer2 ds 1 ; F1
timer3 ds 1 ; F2
timer4 ds 1 ; F3
string ds 1 ; F4
vlongLow ds 1 ; F5
nybs ds 1 ; F6
hexByte ds 1 ; F7
msgLen ds 1 ; F8 count GPS chars per specific message
msgType ds 1 ; F9 Position vs. Velocity GPS NMEA msg
commaCount ds 1 ; FA detect fields within the NMEA msg
screenToShow ds 1 ; FB toggle thru several screens as this incrs
savedStart ds 1 ; FC flag for initial pos save
charsPerLine ds 1 ; FD
; FE, FF unused space
;-------------------------------------------------------
org 0
;-------------------------------------------------------
; interrupt service routine (currently unused)
;-------------------------------------------------------
isr
reti
;-------------------------------------------------------
; main program
;-------------------------------------------------------
start_point
mode $0F ; prepare for configuring direction mode
; see pg. 144 SZ-key dev man
mov !ra,#%11111110 ; only a0 outie; the rest innie
mov !rb,#%11111111 ; all bs innies
mode $0E ; prepare for configuring pull-up resistor mode
mov !ra, #%0000 ; enable all port A pull-ups
;
; ; these not currently used; here for reference:
; mode $0D ; CMOS/TTL input (n/a when Schmidt used)
; mov !rb,#%00000000 ; set all to CMOS
; mode $0C ; schmidt trigger
; mov !rb,#%00000000 ; all schmidts enabled (pg. 59 and 140)
; mode $0B ; wake-up enable
; mov !rb,#%11111110 ; wake-up interrupt edge bit 4 (pin 1)
; mode $0A ; rising/falling: default falling edge
; mode $09 ; swap W, edge det status (pg. 61)
; mov !rb, %00000000 ; clear edge status
; (and store state in "w" reg)
;-------------------------------------------------------
; main loop
;-------------------------------------------------------
main
call @init
call @hello
; call subtest
; call multTest
; call @binToASCIITest
jmp @getGPSMsgGrp ; get GPS message; display to LCD
jmp main
; End of main
;-------------------------------------------------------
; some strings
shello dw 'Hello World! HaWaYa?',0
sline2 dw 'GPS LCD ver 04.19.04',0
nosync dw 'No signal',0
latToGo dw '03741.3430',0
lonToGo dw '12153.3754',0
;-------------------------------------------------------
; Can't call a function located in the second half of any code page so
; compensate by using this jump table which can reference functions on any
; part of any page.
; This table must exist entirely in a first page half.
; If this grows too large, continue on the top half of other code pages.
; Check gps_lcd.lst: last table entry must be below $FF. "$B2" as of last check.
init jmp @_init
hello jmp @_hello
getByte jmp @_getByte
sendByte jmp @_sendByte
sendSpace jmp @_sendSpace
sendString jmp @_sendString
clearScreen jmp @_clearScreen
lcdLine1 jmp @_lcdLine1
lcdLine2 jmp @_lcdLine2
sendHexByte jmp @_sendHexByte
hexNybble jmp @_hexNybble
halfDelay jmp @_halfDelay
delay9600 jmp @_delay9600
delay1ms jmp @_delay1ms
delay100ms jmp @_delay100ms
delay1sec jmp @_delay1sec
longLow jmp @_longLow
multiply32 jmp @_multiply32
subtract32 jmp @_subtract32
increment32 jmp @_increment32
copy32 jmp @_copy32
showHex32 jmp @_showHex32
shift32 jmp @_shift32
clearAccum jmp @_clearAccum
multPreset jmp @_multPreset
DDMMToBin jmp @_DDMMToBin
Lat2Feet jmp @_Lat2Feet
Lon2Feet jmp @_Lon2Feet
loadLatLon jmp @_loadLatLon
multTest jmp @_multTest
latToBinTest jmp @_latToBinTest
latSubTest jmp @_latSubTest
binToASCII jmp @_binToASCII
binToASCIITest jmp @_binToASCIITest
showDirSpeed jmp @_showDirSpeed
showDistHome jmp @_showDistHome
showLatLon jmp @_showLatLon
showTimeAlt jmp @_showTimeAlt
padLine jmp @_padLine
loader jmp @_loader
;-------------------------------------------------------
_init
; to init the LCD, we need to set its bit low on power-up and
; keep it there for a second, otherwise the LCD driver goes into debug mode.
mov ra, #0 ; initialize the LCD bit
call @delay1sec
bank bank_assorted ; set flag: not yet saved the
mov savedStart, #0 ; initial position lat and lon
mov FSR, #latASCII ; preset the lat hundreds digit to 0 so
mov ISR, #'0' ; Lat "DD" can be processed like lon "DDD"
retp
;--------------------------------------------------------------------
; GPS-receive,parse,LCD-send section.
; These aren't calleable subroutines - they jump from code block to
; code block as individual RS232 characters arrive and are processed,
; then jump back to one of two re-entry points:
; 1. the top, just below here, to get a new message group, or
; 2. just below that, to get a new character of the current group.
;--------------------------------------------------------------------
getGPSMsgGrp
; Begin wait for a group of GPS NMEA messages.
;
; Once a second, the GPS sensor sends a series of the NMEA messages,
; then pauses for about 3/4 of a second.
; When this program is synchronized to the sensor, the code will
; wait here for the next message group to start to arrive.
; It will recieve all message group characters, process the received
; data, display information onto the LCD, then jump back here to wait
; for the next message group.
; On any errors, the code jumps back here to begin a fresh message group wait.
bank bank_assorted
clr msgLen ; length of single NMEA message.
clr commaCount ; count fields within NMEA message group.
mov FSR, #altStart ; preset the altitude.
:loop1 mov IND, #' ' ; Altitude and speed are variable length.
inc FSR ; when out of sync nothing arrives.
cjb FSR, #altEnd, @:loop1 ; But when in sync, only the necessary number
; of chars arrive to describe the current value.
mov FSR, #speedStart ; So if we go from 100 to 99 meters altitude,
:loop2 mov IND, #'_' ; the "1" stays unless it is explicitly
inc FSR ; written over.
cjb FSR, #speedEnd, @:loop2
mov FSR, #dirStart ; preset direction. May be unnecessary.
:loop3 mov IND, #'_'
inc FSR
cjb FSR, #dirEnd, @:loop3
call @longLow ; wait for long pause in received RS232
;-------------------------------------------------------
getGPSchar
call @getByte ; get the next RS232 GPS character
;
bank bank_assorted ; An NMEA GPS msg begins with "$"
inc msgLen ; Count received chars in this msg.
cjne RS232in, #'$', @parseMsg ; If not "$" then parser gets it.
mov msgLen, #1 ; If is "$" then reset counter and
jmp @getGPSchar ; wait for next char.
;-------------------------------------------------------
parseMsg
; Use characters 2-6 to determine the message type.
; GPGGA: time, lat, lon, alt
; PGRMV: velocity N, E, Up
; PGRMT: status message always sent once per minute. not real interesting.
; GPRMC: absolute velocity and compass bearing
; GPVTG: maybe use this someday?
;
; Once we're past character 6, process the message body
; (except if over 80 then probably an error occurred, so reset.)
cje msgLen, #2, @msgChar2 ; expect 'G' or 'P'
cjbe msgLen, #5, @getGPSchar ; go get another char
cje msgLen, #6, @msgChar6 ; expect 'A' or 'G'
cjae msgLen, #80, @getGPSMsgGrp ; reset if count too big
jmp @processChar ; on any other message position,
; let subroutine decide what to do.
;-------------------------------------------------------
msgChar2
; Verify that character 2 is either P or G.
; If G, set the message type to "P" for Position message.
; (will overwrite this if char 6 is also "G")
cje RS232in, #'P', @getGPSchar ; may be info msg
cjne RS232in, #'G', @getGPSMsgGrp ; by here, if not G, not ok.
mov msgType, #'P' ; P for Position message
jmp @getGPSchar ; and wait for the next character
;-------------------------------------------------------
msgChar6
; Verify that character 6 is either A (GPGGA) or G (GPVTG)
cje RS232in, #'A', @getGPSchar ; OK; we have GPGGA
cjne RS232in, #'G', @getGPSMsgGrp ; by here, if not G, not ok.
mov msgType, #'V' ; V for GPVTG velocity type message
jmp @getGPSchar ; go wait for the next character
;-------------------------------------------------------
processChar
; if this character is data, then go process it.
; if it is a field separator then go process that.
; (ahh, the velocity message terminates the last field with "*",
; so it is a field separator in that case, also.)
cje RS232in, #',', @field ; comma - go directly to "field";
cjne RS232in, #'*', @processData ; if not * then go process char.
cjne msgType, #'V', @getGPSchar ; if * but not vel then get next gps,
; else fall into "field".
;-------------------------------------------------------
field
; we have a field separator.
; Do two things:
; 1. prepare for a new field by incrementing commaCount and clearing msgBytes.
; 2. If we have received all the fields we're expecting (currently hex 16),
; (see half a page down for more description of the commaCounts), then
; skip the rest of the message group and display what we've got.
; Otherwise go get yet another GPS character.
inc commaCount
clr msgBytes
cje commaCount, #$16, @doDisplay
jmp @getGPSchar
;-------------------------------------------------------
processData
; we have a data character.
; decide what to do based on the current commaCount.
; Note: let the commaCount manage the entire message group, based
; on the GPS sensor always sending the messages in the same order.
; Is this assumption warranted? It works so far...
; Otherwise would need to test both message type and commaCount...
;
; 1 2 3 4 5 6 7 8 9 A B C DE
; $GPGGA,205343,3749.9327,N,12232.3580,W,1,08,1.1,12.5,M,-28.0,M,,*42
; $PGRMV,0.0,0.0,0.0*5C
; $PGRMT,GPS 25-LVC VER 2.50 ,P,P,R,R,P,,19,R*15
;
; as of 3/28/04 no more PGRMV message.
; instead, configured GPS to send GPVTG (Track Made Good and Ground Speed)
;
; commas 1 2 3 4 5 6 7 8
; or, if continuing the commaCount from the previous field...
; F 0 1 2 3 4 5 6 <- that is, 0x16 is the last expected comma.
; fields 1 2 3 4 5
; $GPVTG, ,T, ,M, ,N, ,K *..
;
; 1: true course: 000.0 to 359.0 degrees
; 2: magnetic course 000.0 to 359.0
; 3: speed: 000.0 to 999.9 knots
; 4. speed: 0000.0 to 1851.8 kilometers per hour
; 5: mode - do I care? not sure, yet.
; when saving individual characters, detect field position by the count
; of the comma preceding the field.
cje commaCount, #$01, @timeField ; 6 time chars
cje commaCount, #$02, @latField ; 8 latitude chars
cje commaCount, #$04, @lonField ; 9 longitude chars
cje commaCount, #$06, @statusField ; 1 status char;
cje commaCount, #$09, @altField ; 0 to 5 altitude chars
cje commaCount, #$0F, @dirField ; 0 to 5 direction chars
cje commaCount, #$15, @speedField ; 0 to 6 speed chars
; if no more fields are of interest then just go get another GPS character:
jmp @getGPSchar
;-------------------------------------------
; Save characters into individual RAM banks.
timeField ; always 6 characters: $10 to $15
mov FSR, #timeStart
jmp @saveChar
latField ; probably always 8 characters: $16 to $1D
mov FSR, #latASCII ; GPS sends only 2 digits of lat degrees
inc FSR ; so incr FSR once before using it
jmp @saveChar
lonField ; probably always 9 chars $30 to $38
mov FSR, #lonASCII
jmp @saveChar
statusField ; always 1
mov FSR, #statusChar
jmp @saveChar
altField ; varies from 0 to 4 or 5: $39 to $3D?
mov FSR, #altStart
jmp @saveChar
dirField ; varies from 0 to 6
mov FSR, #dirStart
jmp @saveChar
speedField ; varies from 0 to 6
mov FSR, #speedStart
jmp @saveChar
; add additional field storage here, if you want any
saveChar
; saveChar: jump here with FSR containing the start address of
; the field that we're saving to. So if we add the current value
; of the msgBytes to the FSR, then we have the storage of this character
; within each field. Yeah, if more chars arrive than we're expecting
; then we'll overwrite some other value...Lets just see if that ever happens.
; (Oh no, a hacker could feed a virus in and hijack the project via field overflow!)
add FSR, msgBytes
mov IND, RS232in
inc msgBytes
jmp @getGPSchar ; go get the next char
;-------------------------------------------------------
doDisplay
; Process and display information.
; The first time that a good set of satellite data is seen,
; save the latitude and longitude binary numbers.
bank bank_assorted
cje savedStart, #1, @:continue ; if 1 then already saved.
bank bank_lonstat
cjne statusChar, #'1', @:continue ; unless 1, sat data not good
mov pointer1, #latASCII ; point to Latitude 0DDMM.MMMM
call @DDMMToBin ; convert to binary
mov pointer1, #accumStart ; and save
mov pointer2, #latAtStart
call @copy32
mov pointer1, #lonASCII ; point to Longitude DDDMM.MMMM
call @DDMMToBin ; convert to binary
mov pointer1, #accumStart ; and save
mov pointer2, #lonAtStart
call @copy32
bank bank_assorted ; OK, we've saved the
mov savedStart, #1 ; starting location!
:continue
; Toggle thru several screens; approximately 1 per second.
;
; 0: display current position and time
; 1: display elapsed time since first satellite sync
; 2: display distance from position of first satellite sync
; 3: (todo) display distance to programmed waypoint
; 4: display current velocity, compass heading
bank bank_assorted
inc screenToShow
cjb screenToShow, #4, @showScreen ; "4" is total number of screens
clr screenToShow
showScreen:
cje screenToShow, #0, @showLatLonspeed
cje screenToShow, #1, @showLatLonDH
; cje screenToShow, #2, @showLatLonDH
; cje screenToShow, #3, @showLatLonDH
cje screenToShow, #2, @showLatLonspeed
cje screenToShow, #3, @showLatLonAlt
; cje screenToShow, #3, @showBinary
; Any individual screen display routine may optionally delay for some
; length of time, like a second or so, to better show its contents,
; before jumping back to wait for the next message group.
; This may cause the program to skip message groups. Ordinarily
; this should be no big deal - missing a group is always a possibility,
; and every GPS data processing routine must allow for this.
; But ideally we will be able to catch every group.
;
; Each of the screen display routines will conclude by jumping
; to wait for a new GPS message group as in the following jmp,
; shown just below, although this particular jmp should never
; be reached if the above screenToShow is working properly:
jmp @getGPSMsgGrp
;-------------------------------------------------------
showLatLonAlt
; On the top line show ASCII Latitude, Longitude.
; On the second line show the time and altitude (if in sync)
call @lcdLine1
call @showLatLon
call @lcdLine2
call @showTimeAlt
jmp @getGPSMsgGrp
;-------------------------------------------------------
showLatLonSpeed
; On the top line show ASCII Latitude, Longitude.
; On the second line show the speed and direction
call @lcdLine1
call @showLatLon
call @lcdLine2
call @showDirSpeed
jmp @getGPSMsgGrp
;-------------------------------------------------------
showLatLonDH
; On the top line show ASCII Latitude, Longitude.
; On the second line show the distance from the start.
call @lcdLine1
call @showLatLon
call @lcdLine2
call @showDistHome
jmp @getGPSMsgGrp
;-------------------------------------------------------
showBinary
; convert the current longitude and latitude to 4 byte integers
; representing 1/10000 of a minute, and display.
call @clearScreen ; prepare the LCD to show results
mov pointer1, #latASCII ; point (1 below) Latitude DDMM.MMMM
call @DDMMToBin ; convert to binary
call @lcdLine1 ; On the LCD top line...
mov pointer1, #accumStart
call @showHex32 ; show 4 hex bytes
mov pointer1, #lonASCII ; point to Longitude DDDMM.MMMM
call @DDMMToBin ; convert to binary
call @lcdLine2 ; On the LCD bottom line...
mov pointer1, #accumStart
call @showHex32 ; show 4 hex bytes
jmp @getGPSMsgGrp
; END of GPS receive message jump routines
;
;**************************************************************************
; code below are subroutines.
; general groups:
;
; Latitude, Longitude management group
; Math group
; LCD group
; RS232 group
; test routine group
;
;**************************************************************************
; Latitude, Longitude management group
;
;-------------------------------------------------------
_showDistHome
; Display the distance in feet from first sync to the current LCD line.
bank bank_assorted
cjne savedStart, #1, @:continue
mov pointer1, #latASCII ; point to Lat, cvrt to binary
call @DDMMToBin ; and leave result in accumulator
mov pointer1, #latAtStart ; copy original saved lat binary
mov pointer2, #multStart ; to the other 4-byte register
call @copy32
call @subtract32 ; get the diff...
bank bank_math
cje negFlag, #0, @:P0 ; test whether we're north or
mov RS232out, #'N' ; south of the starting sync
jmp @:P1
:P0 mov RS232out, #'S'
:P1 call @sendByte ; display compass direction
call @Lat2Feet ; convert difference to feet
mov pointer1, #accumStart
call @showHex32 ; show feet as 4 hex bytes
call @sendSpace
call @sendSpace
mov pointer1, #lonASCII ; point to Lon, cvrt to binary
call @DDMMToBin ; and leave result in accumulator
mov pointer1, #lonAtStart ; copy original saved lon binary
mov pointer2, #multStart ; to the other 4-byte register
call @copy32
call @subtract32 ; get the diff...
bank bank_math
cje negFlag, #0, @:P2 ; test whether we're east or
mov RS232out, #'W' ; west of the starting sync
jmp @:P3
:P2 mov RS232out, #'E'
:P3 call @sendByte ; display compass direction
call @Lon2Feet ; convert difference to feet
mov pointer1, #accumStart
call @showHex32 ; show feet as 4 hex bytes
call @sendSpace
:continue
retp
;-------------------------------------------------------
_showLatLon
; Display the current latitude and Longitude to the current LCD line.
mov FSR, #latASCII ; send 9 latitude chars
inc FSR ; skip dummy "0" at lat beginning
:loop1 mov RS232out, IND
call @sendByte
inc FSR
cjbe FSR, #latEnd, @:loop1
call @sendSpace
mov FSR, #lonASCII ; send 10 longitude characters
:loop2 mov RS232out, IND
call @sendByte
inc FSR
cjbe FSR, #lonEnd, @:loop2
retp
;-------------------------------------------------------
_showDirSpeed
; Display the current direction and speed to the current LCD line.
; (if the status says we're not in sync then just report that and quit)
bank bank_lonstat
cjne statusChar, #'1', @saynosync
mov RS232out, #'D' ; send dir label
call @sendByte
call @sendSpace
mov i, #5
mov FSR, #dirStart ; send 6 dir chars
:loop1 mov RS232out, IND
call @sendByte
inc FSR
djnz i, @:loop1
call @sendSpace
mov RS232out, #'S' ; send speed label
call @sendByte
call @sendSpace
mov i, #6
mov FSR, #speedStart ; send ? speed characters
:loop2 mov RS232out, IND
call @sendByte
inc FSR
djnz i, @:loop2
call @padLine ; clear rest of line with spaces
retp
;-------------------------------------------------------
_showTimeAlt
; Show time and altitude. Time is always available, but if not
; in sync then alt is not available.
mov FSR, #timeStart ; send 6 time characters
:loop mov RS232out, IND
call @sendByte
inc FSR
cjbe FSR, #timeEnd, @:loop
showalt
call @sendSpace
mov RS232out, #'h' ; send height label
call @sendByte
call @sendSpace
bank bank_lonstat
cjne statusChar, #'1', @saynosync
mov FSR, #altStart ; send 4 or so altitude characters
:loop mov RS232out, IND
call @sendByte
inc FSR
cjb FSR, #altEnd, @:loop
call @padLine
retp
saynosync
mov W, #nosync
call @sendString
call @padLine
retp
;-------------------------------------------------------
_Lat2Feet
; Enter with mult holding the binary of the latitude that
; we want to calculate distance from.
; Return with the accumulator containing the feet from the current
; latitude to the pointed-to latitude.
; negFlag set to 1 if we're South of the reference; 0 if North.
; one minute of Lat ~ 6072 feet; 6072/10000 = 0.6072; ~ 39/64
call @clearAccum
bank bank_math
mov eight, #$27 ; multiply by 39 (0x27), leaving the
call @multiply32 ; product in the accumulator.
bank bank_math
mov eight, #6 ; divide by 64 by shifting 6
call @shift32
retp
;-------------------------------------------------------
_Lon2Feet
; Enter with mult holding to the binary of the longitude that
; we want to calculate distance from.
; Return with the accumulator containing the feet from the current
; longitude to the pointed-to longitude.
; negFlag set to 1 if we're East of the reference; 0 if West.
; one min of Lon at 37 deg ~ 4790 feet; 4790/10000 = 0.4790; ~ 122/256
call @clearAccum
bank bank_math
mov eight, #$7A ; multiply by 122 (0x7A), leaving the
call @multiply32 ; product in the accumulator.
bank bank_math
mov eight, #8 ; divide by 256 by shifting 8
call @shift32
retp
;-------------------------------------------------------
_shift32
; divide the 4 byte number at pointer1 by (2 to the power of (eight))
bank bank_math
:divideby
clc ; On rotate, carry bit would rotate
rr accum3 ; into hi bit of mult3, which we
rr accum2 ; don't want, so clear it.
rr accum1
rr accum0
djnz eight, @:divideby
retp
;-------------------------------------------------------
_clearAccum
bank bank_math ; prepare for a 4-byte by 1 byte
clr accum0 ; multiplication.
clr accum1 ; Don't touch the 4 "mult" bytes,
clr accum2 ; because subtract has populated them.
clr accum3
retp
;-------------------------------------------------------
_DDMMToBin
; Convert a quantity in degrees, minutes and decimal minutes from
; 10 ASCII characters in the form DDDMM.MMMM to a 4 byte binary value
; representing ten-thousanths of a minute. (about 6 inches of distance
; when the DDMM is latitude or longitude).
; Call with "pointer1" pointing to the start of the DDDMM.MMMM to convert.
; results will be in the 4 byte accumulator.
;
; any advantage to moving the constants below to a code area lookup table?
; no, looks like would take as much work to set up each load as to
; simply load literals as below.
call @clearAccum
call @multPreset
mov mult3, #$03
mov mult2, #$93 ; hundreds of degrees to minutes: x 6000
mov mult1, #$87 ; minutes to 1/10000 of minute: x 10,000
mov mult0, #$00 ; 600 000 000 = $03 93 87 00
call @multiply32
call @multPreset
mov mult2, #$5B ; tens of degrees to minutes: x 600
mov mult1, #$8D ; minutes to 1/10000 of minute: x 10,000
mov mult0, #$80 ; 60 000 000 = $5B 8D 80
call @multiply32
call @multPreset
mov mult2, #$09 ; degrees to minutes: x 60
mov mult1, #$27 ; minutes to 1/10000 of minute: x 10,000
mov mult0, #$C0 ; 600 000 = $09 27 C0
call @multiply32
call @multPreset
mov mult2, #$01
mov mult1, #$86 ; tens of mins to 1/10000 of minute: x 100,000
mov mult0, #$A0 ; 100,000 = $01 86 A0
call @multiply32
call @multPreset
mov mult1, #$27 ; minutes to 1/10000 of minute: x 10,000
mov mult0, #$10 ; 10,000 = $27 10
call @multiply32
inc pointer1 ; skip the decimal point
call @multPreset
mov mult1, #$03 ; tenths of minute to 1/10000 of minute: x 1000
mov mult0, #$E8 ; 1000 = $03 E8
call @multiply32
call @multPreset
mov mult0, #$64 ; 100 = $64
call @multiply32
call @multPreset
mov mult0, #$0A ; 10 = $0A
call @multiply32
call @multPreset
mov mult0, #$01 ; 1
call @multiply32
retp
_multPreset
mov FSR, pointer1 ; operate on the digit that "pointer"
mov temp, IND ; currently is pointing to
bank bank_math ;
sub temp, #'0' ; Adjust ASCII to number
mov eight, temp ; write to the single-byte multiplier loc
mov mult3, #$00 ; these usually must be zero. When
mov mult2, #$00 ; not, let the above prg overwrite 0.
mov mult1, #$00
inc pointer1
retp
;**************************************************************************
; math subroutines
;
; multiply32 (eight) x (mult) -> (accum)
; increment32 (pointer1)++
; subtract32 (abs(mult - accum)) -> accum; negFlag=1 if minus
; clear32 (pointer1) -> 0
; showHex32 (pointer1 -> 8 hex nybbles -> LCD
; copy32 (pointer1) -> (pointer2)
;
;
;-------------------------------------------------------
_multiply32
; Multiply the 8 bit number in "eight" times the 32 bits in mult0-mult3,
; storing the result in the 4 accumulator bytes accum0-accum3.
; Uses "counter".
; This does not preclear the accumulator, so it can be used for repeated
; multiplications where the results all need to be accumulated together,
; so should call clearmult before its first use.
bank bank_math
mov counter, #8
multloop:
rr eight ; move least bit of "eight" into carry register
jnc @rotate ; if it's 0, don't do any adding
clc
add accum0, mult0 ; add byte 0...
addb accum1, C ; then first add the carry bit into byte1,
add accum1, mult1 ; then add the byte, making the byte 2 carry...
addb accum2, C
add accum2, mult2
addb accum3, C
add accum3, mult3
rotate:
clc ; When we rotate, the carry bit would rotate
rl mult0 ; into the low bit of mult0, which we don't
rl mult1 ; want, so clear it.
rl mult2
rl mult3
djnz counter, @multloop
retp
;-------------------------------------------------------
_subtract32
; Subtract 4 bytes: Absolute value(Mult - Accum) -> Mult.
; If the result is below zero then fix: invert and add 1, a la 2's complement,
; and set a "negative" flag.
bank bank_math
mov negFlag, #0
sub mult0, accum0
jc @:p1
inc accum1
:p1 sub mult1, accum1
jc @:p2
inc accum2
:p2 sub mult2, accum2
jc @:p3
inc accum3
:p3 sub mult3, accum3
jc @:done ; if result >= 0 then done.
mov negFlag, #1 ; Otherwise, set negative flag
not mult0 ; and twiddle the results to be
not mult1 ; as if we subtracted mult from accum.
not mult2 ; (NOT the 4 bytes, then add 1)
not mult3
clc
add mult0, #1
addb mult1, C
addb mult2, C
addb mult3, C
:done retp
;-------------------------------------------------------
_increment32
; increment the pointed-to set of 4 bytes
; mainly for testing various 4-byte math routines
mov FSR, pointer1
add ISR, #1 ; incr LSB, setting the carry bit appropriately
inc FSR
addb ISR, C ; if there's a carry bit then pass it along...
inc FSR
addb ISR, C ; and here...
inc FSR
addb ISR, C ; me, too.
retp
;-------------------------------------------------------
_copy32
; copy values of 4 bytes starting at pointer1 to 4 bytes at pointer2
; modifies pointer1, pointer2, temp
mov i, #4
:loop
mov FSR, pointer1 ; operate on the digit that "pointer"
mov temp, IND ; currently is pointing to
mov FSR, pointer2 ; operate on the digit that "pointer"
mov IND, temp
inc pointer1
inc pointer2
djnz i, :loop
retp
;-------------------------------------------------------
_showHex32
; show contents of four bytes in hex pointed to by "pointer1".
mov FSR, pointer1
inc FSR
inc FSR
inc FSR
mov RS232out, ISR
call @sendHexByte
mov FSR, pointer1
inc FSR
inc FSR
mov RS232out, ISR
call @sendHexByte
mov FSR, pointer1
inc FSR
mov RS232out, ISR
call @sendHexByte
mov FSR, pointer1
mov RS232out, ISR
call @sendHexByte
retp
;**************************************************************************
; LCD functions
_hello
call @clearScreen
call @delay100ms
call @lcdLine1
mov W, #shello
call @sendString
call @delay100ms
call @lcdLine2
mov W, #sline2
call @sendString
call @delay1sec
retp
;---------------------------------------------------------
_sendHexByte
; write value, 0-255, in "RS232out", to LCD in two hex bytes.
bank bank_assorted
mov hexByte, RS232out ; save the value because "RS232out"
mov nybs, hexByte ; is destroyed in hexNybble
swap nybs
call @hexNybble
bank bank_assorted
mov nybs, hexByte
call @hexNybble
retp
_hexNybble
and nybs, #$0F ; cvrt 4 bits to hex and send to LCD
clc ;
csa nybs, #$9 ; if > 9, skip jmp and do add.
jmp @:label
clc ; required if clearx is set
add nybs, #$7
:label add nybs, #$30
mov RS232out, nybs
call @sendByte ; send byte to the LCDisplay
retp
;--------------------------------------------------
_sendString
; Send 0-terminated string of up to 20 chars to LCD
bank bank_assorted
mov string,w
:loop
mov w,string
mov m,#0
iread ; reads value from 11-bit code address in M, W
test w
jnz @:send
retp
:send mov RS232out, w
call @sendByte
bank bank_assorted
inc string
jmp @:loop
;--------------------------------------------------
_clearScreen
mov RS232out, #$FE
call @sendByte
mov RS232out, #$1
call @sendByte
bank bank_assorted
mov charsPerLine, #0
call @delay1ms
retp
;--------------------------------------------------
_lcdLine1
mov RS232out, #$FE
call @sendByte
mov RS232out, #$80
call @sendByte
bank bank_assorted
mov charsPerLine, #0
retp
;--------------------------------------------------
_lcdLine2
mov RS232out, #$FE
call @sendByte
mov RS232out, #$C0
call @sendByte
bank bank_assorted
mov charsPerLine, #0
retp
;--------------------------------------------------
_sendSpace
mov RS232out, #' '
call @sendByte
retp
;--------------------------------------------------
_padLine
bank bank_assorted
:loop
cjae charsPerLine, #20, @:done
call @sendSpace
jmp @:loop
:done
retp
;--------------------------------------------------
;**************************************************************************
; delay functions
_delay1sec
bank bank_assorted
mov timer4,#9
:loop call @delay100ms
bank bank_assorted
djnz timer4, @:loop
retp
;--------------------------------------------------
_delay100ms
bank bank_assorted
mov timer3, #99
:loop call @delay1ms
djnz timer3, @:loop
retp
;--------------------------------------------------
_delay1ms
bank bank_assorted
mov timer2, #9
:loop call @delay9600
bank bank_assorted
djnz timer2, @:loop
retp
;--------------------------------------------------
;**************************************************************************
; RS232 functions
_longLow
; Loop until a GPS message arrives.
; method: loop over the time of about 2 characters, testing
; for a hi bit twice the 9600 baud bitrate. During this looping,
; if a high bit is ever detected, restart the loop from the beginning.
bank bank_assorted
mov vlongLow, #32 ; prepare for loop
:loop
call @halfDelay
test rb.0
jnz @_longLow ; if ever a non-zero bit, getGPSMsgGrp.
djnz vlongLow, @:loop
retp
;-------------------------------------------------------
_getByte
; wait for, then return an RS232 byte in the "RS232in" variable.
bank bank_assorted
test rb.0 ; spin until bit B0 goes high
jz _getByte
call @halfDelay ; wait til middle of start bit
mov bitCount, #8 ; prepare for loop
mov RS232in, #$0 ; and preset result
:loop
call @delay9600 ; wait for middle of data bit
clc ; clear carry bit
rr RS232in ; prepare result for receiving next bit
test rb.0 ; have we received a one or a zero?
jnz @:zerobt ; skip bitset if zero
or RS232in, #$80 ; we got a one, so set hi bit of result byte
:zerobt djnz bitCount, @:loop ; next bit
; done getting bits.
call @delay9600 ; wait for middle of stop bit
retp ; return "RS232in"
;-----------------------------------------------------------
_sendByte
; Send the byte in "RS232out" to the LCD
; Destroys RS232out.
mov bitCount, #8
setb ra.0 ; start bit
call @delay9600
:loop snb RS232out.0 ; 8 data bits
jmp @:sndhi
setb ra.0
jmp @:done
:sndhi clrb ra.0
:done rr RS232out
call @delay9600
djnz bitCount, @:loop
clrb ra.0 ; stop bit
call @delay9600
mov temp, FSR ; count chars sent. Used for padding
bank bank_assorted ; the LCD line with spaces to the end.
inc charsPerLine
mov FSR, temp
retp
;-----------------------------------------------------------
_delay9600
; these are the fundamental delays for RS232, both send and receive.
; tuned via trial and error with what works to the LCD
; 215 10% ok, 205 ok, 200 ok, 198 10% ok, so use 206
call @halfDelay
call @halfDelay
retp
_halfDelay
mov timer1, #206
:loop djnz timer1, @:loop
retp
; This is a version that works properly using a 50 mHz resonator
; instead of the 20 mHz crystal. (But don't like the additional
; current the SX needs: 80 mA - about double that of running at 20.)
;
;halfDelay
; mov timer1, #110
;:loop1 djnz timer1, @:loop1
;:loop2 djnz timer1, @:loop2
;:loop3 djnz timer1, @:loop3
; retp
;**************************************************************************
; test and experimental area
;
; what about a generic loader that uses pointer1 for where to load to,
; a zero-terminated string for what to load...? Any benefit?
; But a zero-terminated string can't load a zero.
; what about instead specifying number of bytes to load?
;
_newLoadLatLon
mov pointer1, latToGo
mov pointer2, #latASCII
mov i, #10
call @loader
mov pointer1, lonToGo
mov pointer2, #lonASCII
mov i, #10
call @loader
retp
;---------------------------------------------------------
_loader
mov M, #0
mov FSR, pointer2
:loop mov W, pointer1
iread
mov IND, W
inc FSR
inc pointer1
djnz i, @:loop
retp
;----------------------------------------------------------
_loadLatLon
mov FSR, #latASCII
mov IND, #'0'
inc FSR
mov IND, #'3'
inc FSR
mov IND, #'7'
inc FSR
mov IND, #'4'
inc FSR
mov IND, #'1'
inc FSR
mov IND, #'.'
inc FSR
mov IND, #'3'
inc FSR
mov IND, #'5'
inc FSR
mov IND, #'5'
inc FSR
mov IND, #'7'
mov FSR, #lonASCII
mov IND, #'1'
inc FSR
mov IND, #'2'
inc FSR
mov IND, #'1'
inc FSR
mov IND, #'5'
inc FSR
mov IND, #'3'
inc FSR
mov IND, #'.'
inc FSR
mov IND, #'3'
inc FSR
mov IND, #'3'
inc FSR
mov IND, #'6'
inc FSR
mov IND, #'5'
retp
;-------------------------------------------------------
subtest
; test 4x4 subtracter by poking in values, timesing, displaying.
:loop
call @delay100ms
call @delay100ms
call @delay100ms
call @delay100ms
bank bank_math
mov mult0, #4
mov mult1, #0
mov mult2, #0
mov mult3, #0
mov accum0, #2
mov accum1, #6
mov accum2, #0
mov accum3, #0
call @clearScreen
call @lcdLine1
bank bank_math
mov pointer1, #multStart
call @showHex32
call @sendSpace
bank bank_math
mov pointer1, #accumStart
call @showHex32
call @subtract32 ; mult - accum -> mult
call @lcdLine2
bank bank_math
mov pointer1, #multStart
call @showHex32
call @sendSpace
bank bank_math
mov RS232out, negFlag
call @sendHexByte
jmp @:loop
retp
;-------------------------------------------------------
_multTest
; test 1x4 multiplier by poking in values, timesing, displaying.
bank bank_math
mov math0, #$01
:loope
call @delay100ms
call @delay100ms
call @delay100ms
bank bank_math
mov mult0, #2
mov mult1, #0
mov mult2, #1
mov mult3, #0
mov accum0, #0
mov accum1, #0
mov accum2, #0
mov accum3, #0
inc math0
mov eight, math0
call @clearScreen
call @lcdLine1
mov pointer1, #multStart
call @showHex32
call @sendSpace
bank bank_math
mov RS232out, math0
call @sendHexByte
call @multiply32
call @lcdLine2
mov pointer1, #accumStart
call @showHex32
jmp @:loope
retp
;-------------------------------------------------------
_latToBinTest
; test latitude to binary conversion: 37 41.3557 -> 01 59 0E 35
call @loadLatLon ; write test lat + lon into "current"
call @clearScreen
call @lcdLine1
call @showLatLon ; outputs exactly 20 characters
mov pointer1, #latASCII
call @DDMMToBin ; convert to binary in accumulator
call @lcdLine2
mov pointer1, #accumStart ; show what we've got:
call @showHex32
retp
;-------------------------------------------------------
_latSubTest
; test latitude subtraction
call @loadLatLon ; write test lat + lon into "current"
call @clearScreen
call @lcdLine1
call @showLatLon ; outputs exactly 20 characters
mov pointer1, #latASCII
call @DDMMToBin ; convert to binary in accumulator
mov pointer1, #accumStart
mov pointer2, #multStart
call @copy32
bank bank_math
clc
add mult0, #1 ; test: tweak one of the numbers: 1 00
stc
sub mult0, #1 ; test other dir: 1 01
call @subtract32
call @lcdLine2
mov pointer1, #multStart ; show what we've got:
call @showHex32
call @sendSpace
bank bank_math
mov RS232out, negFlag
call @sendHexByte
retp
;**************************************************************************
; Experimental area 51
_binToASCIITest
; Testing binToASCII
;
; 1. plug known numbers into hiBin, loBin
; 2. run the routine
; 3. send the 5 digit results to the LCD
; 4. pause half a second
; 5. increment the known numbers by 1, 2, 5, ...
; 6. goto 1
mov pointer1, #0
mov pointer2, #0
:loop
call @delay100ms
call @delay100ms
bank bank_toASCII
mov loBin, pointer1
mov hiBin, pointer2
call @binToASCII
call @clearScreen
call @lcdLine1
mov RS232out, pointer2
call @sendHexByte
mov RS232out, pointer1
call @sendHexByte
call @sendSpace
bank bank_toASCII
mov RS232out, digit5
call @sendByte
bank bank_toASCII
mov RS232out, digit4
call @sendByte
bank bank_toASCII
mov RS232out, digit3
call @sendByte
bank bank_toASCII
mov RS232out, digit2
call @sendByte
bank bank_toASCII
mov RS232out, digit1
call @sendByte
add pointer1, #1
jnc @:loop
add pointer2, #1
jmp @:loop
retp
;-------------------------------------------------------
_binToASCII
; take 2 bytes (hiBin, loBin) and convert to ASCII digits 65535 - 00000
; Basically, think of the bytes as the decimal number.
; For example, if your number is less than 40000 but over 30000,
; then write "3", subtract 30000 from the number, and move on
; to do the same for the thousands place, the hundreds place, ...
;
; recent test: working perfectly for the first byte 0-255, but
; screws up beyond that.
bank bank_toASCII
;---------------------------------------- Top of ten thousands loop
mov counter2, #6
mov hiCmp, #$EA ; EA60 = 60000
mov loCmp, #$60
:tenThousands
cjb hiBin, hiCmp, @:loopOn5 ; if number less than 60000, 50000, ...
cjb loBin, loCmp, @:loopOn5 ; then subtract 10000 and test again.
jmp @:emitDigit5 ; otherwise grab the digit and run...
:loopOn5
sub loCmp, #$10 ; $2710 = 10000
jc @:p51
dec hiCmp
:p51 sub hiCmp, #$27
djnz counter2, @:tenThousands
:emitDigit5
add counter2, #'0' ; When we hit the number that this is
mov digit5, counter2 ; not less than, then BINGO! the counter
sub loBin, loCmp ; holds the digit we want! Subtract off
jc @:p52
dec hiBin
:p52 sub hiBin, hiCmp ; the 10000's place number and continue...
;--------------------------------------- Top of thousands loop
mov counter2, #9
mov hiCmp, #$23 ; $2328 = 9000
mov loCmp, #$28
:thousands
cjb hiBin, hiCmp, @:loopOn4 ; if this number is less than 9000,
cjb loBin, loCmp, @:loopOn4 ; then subtract 1000 and test again.
jmp @:emitDigit4
:loopOn4
sub loCmp, #$E8 ; $03E8 = 1000
jc @:p41
dec hiCmp
:p41 sub hiCmp, #$03
djnz counter2, @:thousands
:emitDigit4
add counter2, #'0' ; When we hit the number that this is
mov digit4, counter2 ; not less than, then BINGO! the counter
sub loBin, loCmp ; holds the digit we want!
jc @:p42
dec hiBin
:p42 sub hiBin, hiCmp
;---------------------------------------- Top of hundreds loop
mov counter2, #9
mov hiCmp, #$03 ; $0384 = 900
mov loCmp, #$84
:hundreds
cjb hiBin, hiCmp, @:loopOn3 ; if this number is less than 900,
cjb loBin, loCmp, @:loopOn3 ; then subtract 100 and test again.
jmp @:emitDigit3
:loopOn3
sub loCmp, #$64
jc @:p31
dec hiCmp
:p31 ; sub hiCmp, #$00 ; $0064 = 100
djnz counter2, @:hundreds
:emitDigit3
add counter2, #'0' ; When we hit the number that this is
mov digit3, counter2 ; not less than, then BINGO! the counter
sub loBin, loCmp ; holds the digit we want!
jc @:p32
dec hiBin
:p32 sub hiBin, hiCmp
;---------------------------------------- Top of tens loop
mov counter2, #9
mov hiCmp, #$00 ; $005A = 90
mov loCmp, #$5A
:tens
cjb hiBin, hiCmp, @:loopOn2 ; if this number is less than 90,
cjb loBin, loCmp, @:loopOn2 ; then subtract 10 and test again.
jmp @:emitDigit2
:loopOn2
sub loCmp, #$A
; jc @:p21
; dec hiCmp
:p21 ; sub hiCmp, #$00 ; $000A = 10
djnz counter2, @:tens
:emitDigit2
add counter2, #'0' ; When we hit the number that this is
mov digit2, counter2 ; not less than, then BINGO! the counter
sub loBin, loCmp ; holds the digit we want!
jc @:p22
dec hiBin
:p22 sub hiBin, hiCmp
;---------------------------------------- Top of Ones part
add loBin, #'0'
mov digit1, loBin
retp
;-------------------------------------------------------
;
; some lookup data tables
; like,
; mov M, lat_table >> 8 ; put top 3 bits into M
; mov W, lat_table ; put bottom 8 bits into W
; IREAD ; read code memory into W
; mov ISR, W ; and move the result into the variable
;-------------------------------------------------------
;org $600
;lat_table dw '03741.3557',0
;lon_table dw '12153.3665',0
; the end
;
;-------------------------------------------------------
; notes
;
; The GPS sensor has the capability to send maybe a dozen standard
; NMEA (G...) and proprietary Garmin (P...) message strings, like
;
; $GPGGA,205343,3749.9327,N,12232.3580,W,1,08,1.1,12.5,M,-28.0,M,,*42
; $PGRMV,0.0,0.0,0.0*5C
; $PGRMT,GPS 25-LVC VER 2.50 ,P,P,R,R,P,,19,R*15
;
; You program the GPS sensor to configure it to enable the messages you
; want at the baud rate you want, by writing a short ASCII configuration
; string into the sensor's RS232 input wire.
; Then, whenever the GPS sensor is powered up, it starts emitting groups of
; all enabled messages, once per second.
; It is up to the user to make sure that you don't enable more characters
; than may be sent in one second at the programmed baud rate.
;
; So once its configured, you send power into the GPS sensor,
; point it at the sky and receive RS232 out a wire.
;
;-------------------------------------------------------
; The LCD works like this. Send RS232 ASCII charscters and they are
; displayed on the LCD.
; RS232 control characters place the "cursor" at the start of line1,
; or line2, or anywhere in the displayable area, actually.
; Other control sequences will clear the screen, draw graphics, etc.
;
;---the end----------------------------------------------------
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