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

[andywpg]

BTW, what are you building? Mine was an idea when I was driving around talking on Amateur Radio Satellites. We were in Grand Forks, North Dakota, and I was waiting for my wife to come out of a store. There happened to be an AO-51 pass happening right then, so I made a couple of contacts - only I had NO IDEA what my grid square was! I used my Winnipeg one, and thought "it would be nice to have a handheld, GPS-based unit that displays your current grid square to 6 digits". And the idea was born. I'll get to it, probably right after I finish the smoker controller I'm working on right now.

Did you happen to notice how I list my location on the forum? I guess great minds really DO think alike!

Andy

[tasmod]

Hi Andy,

The project is already working, I just wanted more information displayed on LCD. The LCD board piggybacks the LCD display. It has a 16F818 which deals with the NMEA string and ADC functions.

It's a GPS Disciplined Oscillator producing 10MHz to 10^-12 signal. For accuracy of frequency and timing for MS and EME.

It remains extremely stable but I am slightly improving it by logging the PLL control voltage and the TCXO temp swing.
By logging I can get a mean control position for either start up purposes or short term 'dropout' from gps. Thus it will keep accuracy for short term outage. If the unit is turned off then on, I can apply the correct PLL control voltage until the gps locks again. Although watching the PLL voltage swing whilst trying to lock was fascinating.

It also produces a very accurate 1PPS output. I later intend to use this to trigger the NMEA sentence display. You may be aware that the sentence suffers from lag or slight offset depending if the gps module decides to send another, other, information sentence. In my case at the moment it is 1.635 secs BEHIND actual time as my module occasionally sends out the powerID string which puts the timing RMC sentence out.
I will be turning all off except the RMC sentence. At the moment it is testing phase.

I get a very strong signal from the 60kHz time signal from Anthorn in the UK so I can actually compare the second epoch via SpecLab software visually.

[Darrel Taylor]

Trying to work through the example in post #1.

gives the grid square for 32.123 W, 14.321 N to be GJ34wg.

The best I can come up with is HK33xv at that location.
Are you sure about the example in post #1?

And it seems that Andy is in Winnipeg Manitoba Canada.
And you are near Gainsborough, U.K.

If those are close, I can't be that far off with the calculations.

[andywpg]

And it seems that Andy is in Winnipeg Manitoba Canada.

Absolutely correct

And you're right - HK33xv is in the ocean off of Cape Verde

And 14.321N 32.123W converts to HK34wh - darn near exactly what you calculated

[Darrel Taylor]

Thanks Andy, I knew I couldn't be that far off.

But apparently, I need to work on the math some more.
Darned Floating-Point ...

[Darrel Taylor]

Woohoo!

HK34wh it is!!
And it's not even midnight yet.

It's some really ugly code right now, will need to add some "Pretty" to it.

Are you guy's using PBP3?

If not, there's only so much "Pretty" I can add.

[tasmod]

Just realised you discerned my physical location from my locator. So your code should be OK.

I did the calc by hand and got it to the example Locator given. ODD. Also needed to reverse calc the 'leftovers'

One thing not mentioned is W is a negative longtitude. I need put an IF THEN in my code to deal with the 180 for a negative W rather than E.


If you have ugly code then that's ok with me. I'm using 2.50 Darrel. Long time coding but not enough to be good with PBP

The routine could also decode the 8th place pair too, which is as close as Maidenhead gets.

[andywpg]

Woohoo!

HK34wh it is!!
And it's not even midnight yet.

It's some really ugly code right now, will need to add some "Pretty" to it.

Are you guy's using PBP3?

I am - I look forward to seeing your code because math and I do not get along well.....

That's actually one of the reasons I have been delaying this project - the math was a bit above me right now.... I have just been using the AMSAT page to convert and see where a grid square takes me on the map.