I'd like to point out that ASCII NMEA messages were only linked to 4800Bd by
a certain number of equip manufacturers as they were operating in the
sailing/autohelm and auto-bridge businesses.
Largely for 'weekend sailors'. E.g. NMEA 1v0-1v5. thereafter it wasn't
fixed.



Professionally, running at 4800 was a pain as it was a bottle neck, many
other data rates were used as standards by Trimble, Ashtech, etc.
'The faster the better' as one got more time to crunch numbers instead of
just reading them in. 9600Bd was much used in the 1990s proceeding to
115200 in the 2010s.

Sometimes one can get serial ports to go even faster to 230400Bd, or just
maybe have to drop down to 57600Bd



See here:-


2 400

the modem speed that every machine came with after 9600 was available...


4 800

!!


9 600

"at last, fast enough!"


14 400

but then came...


19 200

2 x 9 600


28 800

fastest base signal rate on a phone line


38 400

4 x 9 600, popular RS-232 and modem speed


56 000

6 x 9 600, popular modem speed


57 600

popular RS-232 speed


115 200

4 x 28 800



A simplistic viewpoint but valid.



Peter Ebsworth,

Forland,.

_____

From: ukmicrowaves@yahoogroups.com [mailto:ukmicrowaves@yahoogroups.com]
Sent: 11. juli 2016 13:03
To: ukmicrowaves@yahoogroups.com
Subject: Re: [ukmicrowaves] Activity Monday Night





Sir you area genius I now have NMEA thank you so much Andy

All best John

Sent from Yahoo <https://overview.mail.yahoo.com/mobile/?.src=Android> Mail
on Android





Yes, you're right. the @@Ea command was for setting up its own binary
protocol message type.



I've searched back in the archives and found one listing that included
commands to set a Motorola GPS to send NMEA, as part of its setup. Note
the change of baud rate part way through as its native binary ran at 9600
baud, but NMEA standard is (was) 4800 baud



The Code is copied below.



So you are part correct in your setting, but you then need to issue the
command to tell it what NMEA sentences to send, and how often.



Andy



InitGPS

movlw 0x40 ;@@Ci[01] Checksum [cr][lf]

call SendByte9600

movlw 0x40

call SendByte9600

movlw 0x43

call SendByte9600

movlw 0x69

call SendByte9600

movlw 0x01

call SendByte9600

movlw 0x2B

call SendByte9600

movlw 0x0D

call SendByte9600

movlw 0x0A

call SendByte9600



call Delay50



movlw "$" ;$PMOTG,RMC,0001 [cr][lf]

call SendByte4800

movlw "P"

call SendByte4800

movlw "M"

call SendByte4800

movlw "O"

call SendByte4800

movlw "T"

call SendByte4800

movlw "G"

call SendByte4800

movlw ","

call SendByte4800

movlw "R"

call SendByte4800

movlw "M"

call SendByte4800

movlw "C"

call SendByte4800

movlw ","

call SendByte4800

movlw "0"

call SendByte4800

movlw "0"

call SendByte4800

movlw "0"

call SendByte4800

movlw "1"

call SendByte4800

movlw 0x0D

call SendByte4800

movlw 0x0A

call SendByte4800



return



On 11 July 2016 at 09:56, 'g7jtt@yahoo.com' g7jtt@yahoo.com [ukmicrowaves]
<ukmicrowaves@yahoogroups.com> wrote:



Hi Andy was just about to suggest bringing the mini beacon out when I was
about to reply to the GPS message. I'm sure it will generate quite a bit of
interest as it did on its last outing. As to the Motorola GPS it was a
freebie so will keep trying to get it to switch to NMEA can talk to it but
just won't switch the command is @@Ci as far as I can tell. Anyway as you
say it's old hat and there are may alternatives around even with
programmable o/p from a few Hz to MHz so may upgrade one day.
<https://overview.mail.yahoo.com/mobile/?.src=Android>





To add a bit of "something different" I have my new portable mini-beacon on
10368.35MHz that I can take out to a spot - possibly Lane End as well as its
one of the few decent sites around here.



JT4G message ONLY; just a few seconds of carrier and no dinosaur. 100mW to
a 20dB horn so I'll need to know where to point it - Quantocks / Devon
Dorset presumably. Mob phone 07576 765856



ANdy G4JNT







On 10 July 2016 at 21:25, g7jtt@yahoo.com [ukmicrowaves]
<ukmicrowaves@yahoogroups.com> wrote:



Hi all just been speaking to Adrian G4UVZ who is going to go portable
tomorrow from IO81LB06 and now Ed G3VPF will be at IO80QQ42. I will be at
Lane end IO91JA37 we hope to be up and running between 6:30 to 7:00pm I will
have to be gone by 9:00pm due to early start in the morning. So hopefully we
can work a few of you all being well.



John