ublox gps 6, 7, or 8?

Pongo

Senior Member
#1
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.)
 
#2
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
#3
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.
 

Pongo

Senior Member
#6
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
#8
#10
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