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

[tasmod]

Now this is interesting.

If I mess with the size of any 'secs' variables it screws everything up. I can get Lat to 4 decimal places but not Long, it still goes to zero.

Right now I put the code back to original and got IO93ok03kg as the locator. I'm going to reduce this to the 4 pair for display just now, only to get more on screen.

I put my phone with the app running next to the gps antenna.
The phone was showing a fix to 16 sats and gave IO93ok03lh with 53 25.8266 and 0 49.7704 as the co-ordinates.

For mine. When I had the 4 decimal places shown on the display it showed 25.8246

[tasmod]

It's between DEC4 in gps string and Aint in locator code.

I can get the display right but not the locator using DEC4 in the gps string and DIGs in the display LCDOUT.

I can get the locator right but not the position display if I just use latsecs as the variable in the gps input string.

Not knowing how Aint works I'm stumped now.

EDIT:

Just walked the property with the phone. Wow, those squares are small. I get LG, LH, KG, KH and guess where the crossover is, yes, right around the room where the unit is. I think I'll stick to DEC2 for now

[Darrel Taylor]

With DEC4 change it to this for the Longitude ...

;----[convert Longitude Sexagesimal to Decimal Degrees]-------------------------
Aint = LonMinDec : GOSUB ItoFA    ; decimal portion of Minutes
Bint = 10000 : GOSUB ItoFB        ; divided by 10000
GOSUB fpdiv
Bint = LonMin : GOSUB ItoFB       ; add whole portion of Minutes
GOSUB fpadd
Bint = 60 : GOSUB ItoFB           ; divide by 60
GOSUB fpdiv
Bint = LonDeg : GOSUB ItoFB       ; add degrees
GOSUB fpadd
IF LonDir = "W" THEN              ; if west of Prime Meridian
    @ MOVE?FF32 AARGB2, BARGB2    ; copy Float AARG to BARG
    Aint = 0    : GOSUB ItoFA     ; subtract from 0 to negate
    GOSUB fpsub
ENDIF

Bint = 180  : GOSUB ItoFB         ; add 180
GOSUB fpadd

And do the same thing with the Latitude.

[tasmod]

That was it.

Using "DEC4 latsecs/lonsecs" in the gps string and changing to Word size variables uses the 4 decimal places.

Interestingly using battery power for the unit, I got exactly the same reading as the phone app moving the unit around.

Thanks Darrel.

I'm now looking at making the time display more accurate to the second epoch using DT_Ints

[Darrel Taylor]

I got exactly the same reading as the phone app moving the unit around.

Yahooo!

I'm now looking at making the time display more accurate to the second epoch using DT_Ints

If you are going to add interrupts, you'll need to make some changes.

SERIN2's baudrate is software timed, and it doesn't like being interrupted.
You'll have to move the serial lines over to RC6 and RC7 (the USART pins).
Then use HSERIN instead of SERIN2.
HSERIN is not affected by the interrupts.

[tasmod]

Hmm, guess which pins are not catered for on pcb ?

Redesign methinks.

[tasmod]

Redesign completed. New board made where all pins are accessible and pads for option of pullups/down resistors.

I have altered the software to use HSERIN and HSEROUT and all is well at the moment. It is working just fine.

Using the code in previous post:

My aim was to display the clock triggered by the gps pps signal. I tried DT_Ints and added the @ INT_RETURN where the original Clock sub had RETURN. This caused the display to only update the very first square with random characters per second with PPS signal.

This is the setup naming Clock. I wasn't sure where to put the INT_Enable . I tried just after this ASM and at beginning of Clock routine with same result.

;--------------------------------------------------------------------------

ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler    INT_INT,        _Clock,      PBP,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor
ENDASM

;--------------------------------------------------------------------------  
@   INT_ENABLE   INT_INT     ; enable external (INT) interrupts