GNC 255A Flash drive requirements

Jdm

Jdm

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Jdm
Garmin says the 255 should be updated with a 8GB or smaller flash drive??? The cs guy said 16GB works occasionally, but it’s designed to use 8 or less. The Pilot’s Guide mentions nothing about the GB size. I can’t even find 8GB anymore. 16GB is pretty much the bottom. Anyone using larger flash drives? This all sounds very strange being it’s a brand new unit.
 
Other users should chime in shortly, but USB 2 and 8 GB drives are plentiful. one example here.
 
Thanks! I didn’t come up with anything locally.
 
I just went through this with my GTR 225 (GNC 255 minus the nav). I had a larger flash drive (32 or 64 GB) and erased the existing partition and created a 256mb fat32 partition and it worked like a champ. I tried all sorts of different configurations before I found a solution that worked. I have windows. Can't help ya if you're iOS. (If you have windows, press the start key and start typing disk and the top suggested program is something like "create disk partitions" (I'm on android at the moment or I'd run through it). Word of caution- If you need to go through this process, make sure you delete the right partition! Don't come whining that you wiped out your C: drive and had to reinstall windows and you lost all your photos of nana. :rolleyes:

Between my GNX 375, my G5 HSI, and my GTR 225, they all take a different flavor of memory. Respectively, SD, Micro SD, and USB Thumb drive adapter to whatever flavor the GTR has. (It's not mini USB. It's not micro USB. Thankfully, Garmin provided an adapter. God help me if that thing ever goes missing.) T'would be nice if it was all just one flavor. I digress...
 
Nathan Miller said:
Between my GNX 375, my G5 HSI, and my GTR 225, they all take a different flavor of memory.
Click to expand...

I have G5’s. Didn’t realize they require any updating?
Also have 650xi, and GI275. Wish it were an easier way to update everything. I don’t have the FS510 because it won’t work with the GNC255A.
The GI275 will update with USB, but again, the manual doesn’t give flash drive requirements. Garmin CS says the G275 is designed to use 32GB flash drives or lower.
 
Jdm said:
I have G5’s. Didn’t realize they require any updating?
Click to expand...
I just bought my G5 HSI last month. It had with software 6.0 IIRC. When I started my install, version 6.4 was out, so I hooked up the backup battery and popped in a micro SD card with the newest software on it. By the time my install was finished, 6.6 was current and I had to go through it all again.

It's super easy to do. (Once you get the micro SD card formatted right - fat32).

Below are feature upgrades with the G5 software revisions. Garmin doesn't keep the revision list entirely up to date
https://www8.garmin.com/support/download_details.jsp?id=10361

Version 6.4 https://www8.garmin.com/support/collection.jsp?product=K10-00280-00

Scratching my head where I downloaded 6.6 from :confused: I've searched all over. Maybe someone else can chime in on that. Garmin seems like it's losing interest in their G5 now that the GI275 is out :rolleyes:
 
From another thread

WannFly said:
there is 6.6 out there :p

Changes made from version 6.40 to 6.60:
  • Added additional autopilot configuration options
  • Improved GMC 507 calibration procedure
  • Improved navigation source selection from G5 #2
  • Improved density altitude display
  • Improved NMEA GPRMC sentence output
  • General improvements to system operation
  • Includes update to GSA 28 software version 4.60
  • Includes GMC 507 software version 2.90
  • Includes GAD 29 software version 3.20
  • Includes GMU 11 software version 2.00
  • Includes GAD 13 software version 2.00
Click to expand...
 
Nathan Miller said:
Between my GNX 375, my G5 HSI, and my GTR 225, they all take a different flavor of memory.
Click to expand...
Does the GNX375 require a specific SD card? Or will any SD card within a certain size range work?
 
I use the one that came with my unit (or supplied by the dealer).

When my 172 was in the shop getting its GNX 375, I bought a 32gb SD card from Amazon. This was before I knew one came with the unit. The Garmin card is with my plane, so I can't check out what kind it is, but I've used the PNY card with no problems.

I'm glad I don't have the 450/530 data card schemes that require a separate adapter (well, arguably my GTR 225 falls in that category).

Here's the link for the card I bought in December

PNY 32GB Performance Class 4 SD Flash Card (P-SDHC32G4H-GE) https://www.amazon.com/dp/B0019K261G/ref=cm_sw_r_other_apa_i_cJWOEb6Y6RZT4
 
FYI there is a long debate on this forum on whether pilot is allowed to update G5 software on a certificated aircraft or not. not trying to start another debate, just saying, i do my updates at my avionics shop with a log book entry. Your G5 and your aircraft... so your call
 
Interesting. I'll search out the thread.

I admit (that I am currently) on the opposite end of the spectrum from you (and quite surprised it wouldn't be something an owner can do), but I've been wrong more often than right in a lot of ways and I may have just discovered a new one :confused:
 
Nathan Miller said:
Should I (could one?) downgrade to 6.4? Yikes.
Click to expand...
not sure. technically you are flashing the chip of G5, but it also sends flash updates to other connected stuff like GMC 507 , GSA 28 , GAD 29 - you may not have any of them or may have GAD 29. will a "downgrade" flash those chips as well? technically yes, but depends on how garmin has defined the upgrade logic

paging @bnt83

Edit : comparing version of connected devices, looks like only the servo version changed from 6.4 .. so if you dont have the servos, you may be alright. but again i dont know how the downgrade will actually work
 
I'll likely have to wait it out. If I put in a micro SD card with 6.4 on there, it'll look at its 6.6 and pull a PC load letter on me.
 
Nathan Miller said:
I use the one that came with my unit (or supplied by the dealer).

When my 172 was in the shop getting its GNX 375, I bought a 32gb SD card from Amazon. This was before I knew one came with the unit. The Garmin card is with my plane, so I can't check out what kind it is, but I've used the PNY card with no problems.
Click to expand...
Thanks. I checked and the SD card from Garmin is 8GB FAT32 with a volume label of "GARMIN".

The reason I asked is because I was wondering if one could just keep a card in the plane and a card at home and swap them as databases become updated. Sounds like that's the case. It would be much easier than going to the plane, fetching the SD, bringing it home, downloading the update, going back to the plane, etc every 28 days.
 
That's what I do, but I understand you can remove the card after the database is uploaded. Databases are stored internally.

That way you can take the card with you... (Optionally, you can leave it in for data logging.)
 
I’m pretty sure you can downgrade G5 though I’ve never tried it.
 
I successfully got everything updated today. Used the GI 275 dongle/USB with a 16gb flash drive 2.0.
The Pilot Guide was incorrect. Unable to follow the steps because of inaccurate information In the book. Garmin CS was actually very helpful. Said they’d had a lot of complaints. The guy had to look at one himself, and solicit help, but he got to the bottom of it alright.
The 650Xi SD card update was no problem. It went exactly per the Guide step for step.
The GNC255A was ok but the Guide could have been so much better. I ended up using a 2.0 flash drive with 4gb. It loaded fine once I figured out the process.
 
Nathan Miller said:
I just went through this with my GTR 225 (GNC 255 minus the nav). I had a larger flash drive (32 or 64 GB) and erased the existing partition and created a 256mb fat32 partition and it worked like a champ. I tried all sorts of different configurations before I found a solution that worked. I have windows. Can't help ya if you're iOS. (If you have windows, press the start key and start typing disk and the top suggested program is something like "create disk partitions" (I'm on android at the moment or I'd run through it). Word of caution- If you need to go through this process, make sure you delete the right partition! Don't come whining that you wiped out your C: drive and had to reinstall windows and you lost all your photos of nana. :rolleyes:

Between my GNX 375, my G5 HSI, and my GTR 225, they all take a different flavor of memory. Respectively, SD, Micro SD, and USB Thumb drive adapter to whatever flavor the GTR has. (It's not mini USB. It's not micro USB. Thankfully, Garmin provided an adapter. God help me if that thing ever goes missing.) T'would be nice if it was all just one flavor. I digress...
Click to expand...

Does anyone know where to get the usb adapter for the GTR 225?
 
5QK said:
Does anyone know where to get the usb adapter for the GTR 225?
Click to expand...

It looks proprietary, sadly. I have no idea why Garmin didn't just go with a Micro USB or other standard connector. Best best is to call Garmin and order it from them.
 
Isn't their dongle just a Micro-USB male to USB-A female? I don't have one in front of me at the moment to confirm that, but that's what I recall.
 
Ryan Klems said:
Isn't their dongle just a Micro-USB male to USB-A female? I don't have one in front of me at the moment to confirm that, but that's what I recall.
Click to expand...
20200618_17205243.jpg

Garmin on the Left. Micro USB on the right. Looks close, but not quite the same.

I'm going up with my CFII tomorrow morning. I'll *gingerly* try attaching a Micro-USB and I'll report the results.

FWIW - the PN on my Garmin cable is 320-00726-00. Text below that says Rev C and below that says 190520 :dunno:
 
Heh, wow, I guess I never looked close enough! I love Garmin, but man, decisions like that are just a really shake your head kinda thing.
 
*IF* Garmin want's anything more that $20 for their dongle, let me test whether mine will read a database from a USB flash drive using a micro-USB adapter and I'll post the results.

If successful, this item may do the trick for you, but again, I'll test it out tomorrow morning. https://www.amazon.com/dp/B00N9S9Z0G/ref=cm_sw_em_r_mt_dp_U_c296EbDWP3J8H

Edit - Crap! I only have a micro-USB to male USB-A. (need female USB-A). Welp, I won't be able to test out if I can read from a flash drive, but I can at least see if it fits :fcross: You'd be on your own for the rest. Dimensionally, I've been able to confirm with a micrometer that it has the same height and width.
:rollercoaster:
 
FWIW, they both have 5 pins, the G is marked with an A, my generic cable is marked with a B.
I believe the A is an older standard.

Found these male USB-A to female UCB-C adapters:
76f1c064fa625eb553d0f9a6cea251e5.jpg



Tom
 
Last edited:
That looks like it might work
 
Pretty sure the GNC 255 has a Micro AB connector. So both a Micro A and Micro B cable will fit

upload_2020-6-19_9-58-23.png
 
Nathan Miller said:
It looks proprietary, sadly. I have no idea why Garmin didn't just go with a Micro USB or other standard connector. Best best is to call Garmin and order it from them.
Click to expand...

It is no secret... a senior executive from Apple is now a marketing consultant for Garmin. The same guy who brought you this:

iMask options.jpg

(for all you Apple Fanboys, yes I am kidding!)

-Skip
 
20200619_114455.jpg
"B" fits my GTR 225. Can't confirm if the Pin Out is the same between A and B.

I tried searching "microusb A to female USB A" and not much luck at first glance not returning results for B. Maybe the single letters are ignored by Amazons search.
 
Thanks everyone.
 
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