ublox gps 6, 7, or 8?

Pongo

Senior Member
I would like to read the UTC time stamp, and maybe use the 1 pps output, and I'll use a 20X2. For this application is there any advantage to getting a series 7 or 8 module over the cheaper 6 series?

(I have no problem seeing satellites at my location.)
 

neiltechspec

Senior Member
In my opinion, for what you require, no advantage in using a 7 or 8 over a 6.

I changed out all my 6's for 8's on all my copters due to the advantages in positioning accuracy capabilities.
With GPS, EGNOS & GLONASS, position accuracy is 3ft as opposed to 30ft on a 6, receiving between 14 & 16 sat's.

Neil.
 

srnet

Senior Member
I think that staring at V7 the GPS starts up in GLONASS mode, and you may need to configure it to send the GP NMEA.

Version 8 in particular is very low power, average current consumption can be under 10mA in cyclic mode.

A lot of ready built modules may not give access to the 1 pps output.
 

hippy

Technical Support
Staff member
I cannot see that there's much advantage to using V7 or V8 over V6 unless you want something specific which the newer versions offer. The V6 can deliver UTC time and also has a 1 PPS output; that is exposed on JP2 pin 6 if using the GPS010 module -

http://www.picaxe.com/docs/GPS010.pdf
 

Pongo

Senior Member
Update: My ebay $10 ublox NEO-6M module arrived. It has a 3.3 volt regulator on the board. That's not entirely good news, it's convenient to be able to use a 5 volt supply, but the serial in/out connect directly to the ublox and are 3.3 so a little care is required. Despite their disclaimer about not being able to ship the battery, it was already installed. It's a very sensitive receiver, keeps a solid lock indoors, under a metal plate! The u-center configuration tool is a free download. Not surprisingly for the lowest cost variant only a few of the many configuration options are available for the 6M. I set baud rate and "NMEA messages only", but couldn't change the mode from "portable" to "time". The antenna cable is very short, and I couldn't find an IPEX extension cable. I need an alphabet soup of adapters to be able to use my MCX connector remote antenna. All minor issues though, it's a long time since I've had so much fun for $10 :)

neo6m.jpg

For anyone who might need something similar, here's a simple picaxe GPS UTC Clock:

Code:
'PICAXE-20X2
'NEO-6M GPS Module TX Data connected to hserin
'should work with any GPS sending NMEA messages
#picaxe 20x2
#Terminal 9600
#No_Table
#No_Data

Symbol LED = C.5
Symbol ptro  = B22 'used for scratchpad pointer
Symbol ptrn  = B23 'used for scratchpad pointer
Symbol ptrp  = B24 'used for scratchpad pointer
Symbol spd   = B25 'var for data from scratchpad
Symbol spd2  = B29 'var for data from scratchpad

Symbol hh = B26 'hour
Symbol mm = B27 'minute
Symbol ss = B28 'second
Symbol dd = B30 'day
Symbol mo = B31 'month
Symbol yy = B32 'year

Top:
	hsersetup b9600_8, %00 ' set the serial to 9600 baud
Again:
	ptr = 0
'wait for data $GPRMC message from gps and go to whoops if it doesn't arrive before timeout
	hserin [10000,whoops],0,63,("R")
'check for "MC" (77 67) in scratchpad 	
	get 0,spd
	get 1,spd2
	if spd <> 77 OR spd2 <> 67 then Again
'scan for delimiters and store positions in scratchpad starting @ 100	
	ptrn = 100
	for ptr = 0 to 62
		if @ptr = "," and ptrn < 127 then
			put ptrn,ptr
			ptrn = ptrn + 1
		endif
	next
'get the time/date from scratchpad
get 100,ptrp
gosub getdata
hh = spd
gosub getdata
mm = spd
gosub getdata
ss = spd
get 108,ptrp
gosub getdata
dd = spd
gosub getdata
mo = spd
gosub getdata
yy = spd	
sertxd (#hh,":",#mm,":",#ss," ",#mo,"-",#dd,"-",#yy,CR,LF)
goto Again

getdata:
'gets time/date data and converts ASCII to numeric
	ptrp = ptrp + 1
	ptrn = ptrp + 1
	get ptrp, spd
	get ptrn, spd2
	spd = spd - 48 
	spd2 = spd2 - 48
	spd = spd * 10 + spd2	
	ptrp = ptrp+1
	return

whoops:
	SerTxd ("GPS Data Fail")
 	SerTxD (CR, LF)
    	Pause 100
	GoTo Again
	
ledflash:
	High LED
    	Pause 200
    	Low LED
    	Pause 200
    	Return
 

hippy

Technical Support
Staff member

Jeremy Harris

Senior Member
I'm using what looks to be the same UBLOX 6M module, connected directly to a Picaxe serial interface and managed to configure the module (using the U-Center software) to only spit out the GPZDA sentence, at 9,600 baud. It's been running for a few months now, as a master clock for our house data logger and a display on the wall in the hall that gives some measured data and the current day, date and time.
 
Top