How do I discern Maidenhead Locator from GPS lat long info.

[tasmod]

And a WOW from me Darrel. Thanks for your help. Surprisingly I think I can follow and understand the code

Sorry I'm late back to the thread. One of the winter bugs has had hold of me, not the type I can rewrite

The project code I posted above doesn't work in the Serin2 GPS routine. Either the line is incorrect or the speed. I've tried every speed and state but no joy. Signal is at the pic pin every second.

The code compiles but says 'error, expected [ ' but they are there?

I will try out the code shortly, many thanks again.

[Darrel Taylor]

The code compiles but says 'error, expected [ ' but they are there?

The SERIN2 line has a value for the timeout, but there's no label for it to jump to.

[tasmod]

Doh, sometimes you can't see the wood for the trees !

Thanks again Darrel, you've no idea how many times I looked at that line.

Code is working at base level now and info is on screen, next is to incorporate the Locator code of yours.

[Darrel Taylor]

Awesome!

Can't wait to see an IO93ok on that LCD.

[tasmod]

Hi Darrel,
Hmm, I wanted to move on to final stages of the project adding the locator code but before I could I came up against something I've not had before.

I was using a 16f628A and wanted to port across to a 16F818 for a single adc channel use. (Monitor a pll control voltage)

I had errors of "Argument out of range" when I added my usual working ADC code. It works standalone on the 818 nicely.

The code for gps alone works in the 818 as per lcd pic. So I'm lost now.

In the working gps code alone, no adc code. I did have some very odd messages re 'out of range' with the code with END at the finish of the code. It seemed like something was hidden in the space in MCS. Deleting back to the final Goto GPS cleared the messages.

This is the gps code with adc which errors. I daren't add the locator code yet

; 
;
; 			        PIC16F818                             
;                          __________                                          
;     D6-------------RAN2 |1       18| RAN1---------D5                   
;     D7-------------RAN3 |2       17| RAN0---------D4                 
;     LED------------RAN4 |3       16| OSC1--------XTAL                        
;     +5V-----------!MCLR |4       15| OSC2--------XTAL                        
;     Ground----------Vss |5       14| VDD---------+5 V                        
;     NMEA data-------RB0 |6       13| RB7---------Not used                   
;     Serial data out-RB1 |7       12| RB6---------Not used
;     Not used--------RB2 |8       11| RB5---------LCD Enable          
;     Pushbutton------RB3 |9       10| RB4---------LCD Register select         
;                          ----------                                          
; 

;====================================================================='
' Program to display returned value of a GPS on RB0
' LCD in 4-BIT mode PIC16F818 controller 4Mhz clock Fuse PWRT BODEN
' 
'GPS sentence: $GPRMC,192144.62,A,5041.6058,N,00412.6124,E,0.45,3 57.74,081205,,*0B


Define LCD_DREG PORTA          ' Port for LCD Data
Define LCD_DBIT 0              ' Use upper 4 bits of Port  
Define LCD_RSREG PORTB         ' Port for RegisterSelect (RS) bit
Define LCD_RSBIT 4             ' Port Pin for RS bit  (pin9)
Define LCD_EREG PORTB          ' Port for Enable (E) bit
Define LCD_EBIT 5              ' Port Pin for E bit    (pin7)
Define LCB_BITS 4              ' Using 4-bit bus
Define LCD_LINES 4             ' Using 2 line Display
Define LCD_COMMANDUS 1500      ' Command Delay (uS)
define LCD_DATAUS 50           ' Data Delay (uS)

DEFINE OSC 4

OPTION_REG.7=0                 ' Enable Pull-Up's
GPSin VAR PORTB.0
' Initialise ADC
ADCON1 = %10000100 ' Set PORTA analog and RIGHT justify result
ADCON0 = %01010001 ' Configure and turn on A/D Module channel 4 Fosc 8
PAUSE 500

'Declare variables
val VAR WORD      ' final calculated adc valuesWORD' final calculated adc values
volt VAR WORD     ' scaled value real part
voltd1 VAR WORD   ' scaled value first decimal place
voltd2 VAR WORD   ' scaled value second decimal place
i var byte        ' counter

'Allocate Variables for GPS:
TimeOut CON 2000            
                                                            
hh VAR BYTE             'hours
mm VAR BYTE             'minutes
ss VAR BYTE             'seconds
knots VAR WORD          'speed in knots (units)
knotsten VAR BYTE       'speed in knots (tens)
course VAR WORD         'heading
latdeg VAR BYTE         'degrees latitude
latmin VAR BYTE         'minutes latitude
NS VAR BYTE             'north or south
londeg VAR BYTE         'degrees longitude
lonmin VAR BYTE         'minutes longitude
EW VAR BYTE             'east or west
d VAR BYTE              'day
m VAR BYTE              'month
y VAR BYTE              'year

fix VAR WORD 'GPS fix

LCDOut $fe,$80,"   GPS Decoder  "
LCDOut $FE,$c0, "    G8VLQ Mk1  "
Pause 500
LCDOut $FE, 1           'Clear Screen

GPS: 'read GPS

SerIn2 GPSin,188,Timeout,LCD1,[wait("$GPRMC"),wait(","),DEC2 hh,DEC2 mm,DEC2 ss,wait(",")_
,fix,wait(","),DEC2 latdeg,DEC2 latmin,wait(","),NS,wait(","),DEC3 londeg,DEC2 lonmin,_
wait(","),EW,wait(","),knots,wait("."),DEC2 knotsten,wait(","),DEC3 course,wait(","),DEC2 d,DEC2 m,DEC2 y]


IF fix="V" Then         'if no GPS fix
GOTO LCD1
EndIF

gosub PLL

LCD:      
           
LCDOut $fe,$80,DEC2 d,"-",DEC2 m,"-",DEC2 y," ",#volt, ".", # voltd1,# voltd2, "Vdc"            ; 80 1st line   
LCDOUT $fe,$c0,"    ",DEC2 hh,":",DEC2 mm,":",DEC2 ss,"    "                                ; c0 2nd line
LCDOut $fe,$90," LAT: ",DEC2 latdeg,",",DEC2 latmin," ",NS                                 ; 90 3rd line
LCDOut $fe,$d0," LON: ",DEC2 londeg,",",DEC2 lonmin," ",EW                                 ; d0 4th line

GoTo GPS

LCD1:       ; If invalid data, just shows gps string is received

LCDOut $fe,$80,#volt, ".", # voltd1,# voltd2, "Vdc"                                         ; 80 1st line
LCDOUT $fe,$c0,"     No Fix       "                                                       ; c0 2nd line
LCDOut $fe,$90," LAT: ",DEC2 latdeg,",",DEC2 latmin," ",NS                                ; 90 3rd line
LCDOut $fe,$d0," LON: ",DEC2 londeg,",",DEC2 lonmin," ",EW                                ; d0 4th line

goto GPS

LCD2:      ; 20 character display. Put time and date on first line , removed names.
           ; callsign and QRA (maidenhead) on second line

LCDOut $fe,$80,DEC2 d,"-",DEC2 m,"-",DEC2 y,DEC2 hh,":",DEC2 mm                         ; 80 1st line
LCDOut $fe,$80," G8VLQ   "                                                              ; c0 2nd line
LCDOut $fe,$90,"LAT: ",DEC2 latdeg,",",DEC2 latmin," ",NS                                ; 90 3rd line
LCDOut $fe,$d0,"LON: ",DEC2 londeg,",",DEC2 lonmin," ",EW                                ; d0 4th line

GoTo GPS

PLL:
Val = 0                       ' Value returned is the average of 5 conversions
For i = 0 TO 4
ADCON0.4 = 1                  ' Start conversion
NoteDone:
pause 1
IF ADCON0.4 = 1 Then NoteDone
val = val + ((ADRESH * 256)+(ADRESL))
nEXT I
VAL = VAL/5
' Calculate Volatage to 2 decimal places
volt = val * 5/1024
voltd1 = ( val * 5//1024) * 10/1024
Voltd2 = ((val *5 //1024) * 10//1024) * 10/1024
RETURN

[Darrel Taylor]

The 16F628A has 2K words of program space.
The 16F818 only has 1K words.

You're going to need a bigger chip.
The Maidenhead routine with Floating point libraries will take >1.5K by itself.

You'll need at least 4K, but why not get one with 8K so you won't have the problem again later.
I'm sure you'll want to add a Morse Code transmitter and receiver some day.

[tasmod]

Now that was completely stupid of me, I apologise for such a silly mistake. I had never seen the message before and assumed it was a code error.

I never gave it a thought to look at the chip spec. The reason to change over to 818 was just one adc input. The chip otherwise is pin compatible for what I've already done.

I think I will remake a new display pcb and use the 16f876 28 pin chip that has 8k.

The project uses the chip to accept the NMEA string from a Rockwell gps module and display it. This older gps module also produces accurate 1PPS and 10kHz signals when gps has a fix.
I'm using these signals on a pll and divider board to lock a 10mhz tcxo.

In its present application it would have worked fine but I wanted to monitor the gps pll control voltage on the board to check for frequency lock.
If the voltage was 1.65v then the oscillator was in lock state.
The display did show whether the satellites produced a fix but not whether the oscillator had locked against the 10khz frequency. Watching the pll control voltage hunt back and forth whilst the gps attempted a fix was facinating but impractical for 'normal' usage.

Once I have the display running again I'll report back.