I just started dabbling with GPS modules. I got my first one from Amazon for about $12. I didn’t know almost anything about GPS chips but I did know that U-blox chips are pretty prevalent in the Drone community, so I set out to purchase a module with a U-blox chipset. The Amazon one I linked above (which now shows as unavailable, and I hope I had something to do with that) indicates that it has a NEO-8M chip on it.
I plugged the GPS into my computer and started U-blox U-center software. The GPSTXT data indicated
??:??:?? $GPTXT,01,01,02,u-blox ag - www.u-blox.com*50 ??:??:?? $GPTXT,01,01,02,HW UBX-G70xx 00070000 FF7FFFFFo*69 ??:??:?? $GPTXT,01,01,02,ROM CORE 1.00 (59842) Jun 27 2012 17:43:52*59
Say What? I got a U-blox chip all right but it is a U-blox 7th generation with firmware from 2012. Here’s what the label indicated on the chip.
It says NEO-M8N.
Soooooo, someone took a 7th gen chip that is 10 years old and rebranded it to a current production version.
Not only that, the 7th gen chip does have a firmware upgrade however you can’t apply it because whoever made the module board didn’t include flash rom so it simply cannot be upgraded. How cool is that?
After looking up U-blox chips, not the modules, just the chips, it seems most of them are $30 plus at parts places like Mouser and Digikey. So ultimately, if someone is selling a GPS module with a current generation U-blox chip on it for $12 right away you need to know that something is amiss.
Here is an actual U-blox chip and module from Sparkfun.
This chip is marked as a NEO-M9N and is authentic. The startup GPSTXT data indicates:
11:28:50 $GNTXT,01,01,02,u-blox AG - www.u-blox.com*4E 11:28:50 $GNTXT,01,01,02,HW UBX 9 00190000*12 11:28:50 $GNTXT,01,01,02,EXT CORE 4.04 (7f89f7)*3F 11:28:50 $GNTXT,01,01,02,ROM BASE 0x118B2060*20 11:28:50 $GNTXT,01,01,02,FWVER=SPG 4.04*44
It clearly shows 9th generation as indicated on the label. And I looked up the firmware version which is 4.04 which is currently the latest available. Cost of this module though is $70 and it needs a separate antenna.
Here is another real one from Sparkfun. A NEO-M9N with a chip antenna. My point here is you have to test the U-blox chips with their software, U-center.
??:??:?? $GNTXT,01,01,02,u-blox AG - www.u-blox.com*4E ??:??:?? $GNTXT,01,01,02,HW UBX 9 00190000*12 ??:??:?? $GNTXT,01,01,02,EXT CORE 4.04 (7f89f7)*3F ??:??:?? $GNTXT,01,01,02,ROM BASE 0x118B2060*20 ??:??:?? $GNTXT,01,01,02,FWVER=SPG 4.04*44 ??:??:?? $GNTXT,01,01,02,PROTVER=32.01*18 ??:??:?? $GNTXT,01,01,02,MOD=NEO-M9N*7B
Lastly, let’s look at the accuracy. Both the rebranded chip and authentic 9th gen chip were tested in EXACTLY the same spot and were never moved. Not even an inch.
Guess which one is the real one and which one is the fake one?
GPS Tracking Fake Chip vs. Real Chip (click pics to enlarge)
It’s pretty obvious that the tightly clustered photo of tracks directly on my house is the authentic chipset.
If you were looking for your missing drone or weather balloon, which chip would you want?
I have another chip coming from eBay and a couple coming from Aliexpress which both claim to be NEO-6M. I’m willing to bet that those will be fakes as well. The only way to know you are getting an authentic GPS chip is to order via the U-blox authorized dealers. Sparkfun is one and SparkFun has incredible support and a great set up guide which includes schematics as well.
UPDATE: I got my NEO-6M chip from eBay today and all indications are that it is fake as well. Firmware and Hardware reports correctly and all U-blox chips have 3 triangular holes in the shield. But the text console does not report correctly. The first few lines that report the chip is from U-blox ($GPTXT) as above are missing.
FAKE NEO-6M (click pics to enlarge)
I also got 2 chips from AliExpress which also are similar. Firmware shows okay, 3 holes in the can but $GPTXT data missing in the Text Console.
If you buy from anywhere but an authorized dealer you are almost certainly going to receive a fake or rebranded chip.