[Nook HD, HD+ Android Development] wally333:
"Easy" upgrade instructions.

Upgraded my wife's Nook HD+ as the stock 4.0 was not up-gradable to the current versions of her video watching apps -- HBO, Showtime, etc. It was a lot harder than it should have been probably because of the turmoil of CM --> Linage and the fact that any links to the CM download sites didn't work.

In an attempt to help anyone else looking to upgrade, I'll detail what worked and omit all the pain of incompatible versions of OS builds and GAPPS. I would have been happy with Android 6, or probably even Android 5, but was pleasantly surprised to get Android 7 working. MANY THANKS TO ALL THE DEVELOPERS who've done all this great work!

I started with this site found by google, clearest instructions I've found yet, too bad the linked files aren't there anymore or are incompatible versions: https://liliputing.com/2015/09/how-to-install-android-5-1-on-a-nook-hd-or-nook-hd.html

But is did point me to the key piece: ClockworkMod Recovery version emmc-cwm-early3.1.img.gz at:

http://xdaforums.com/showthread.php?t=2600572

I had initially got the Nook specifically to play with CM when B&N was closing them out, but I got one of really hard to get to boot from the SD card versions so I got nowhere, my wife ended up liking it for a few Ebooks but really snagged it after I installed Netflix, HBO, Showtime, etc. apps. So I've ignored it until she started to complain loudly that the video apps wouldn't play anymore. Seems the apps need updates and won't load on less than Android 4.4 :(

I unzipped the CWM Recovery image and wrote it to a 4GB Patriot micro SD card (the same one that didn't boot a few years ago) with dd on Linux. Then I copied the three ZIP files that need to be installed to the SD card (although I've not seen the need to actually use TWRP yet, although I likely will to make a backup now that everything is basically working fine, albeit with a few quirks). Now that my card was ready I inserted it into the powered off NOOK HD+ and powered on.

I installed in this order, after booting the CWM Recovery from the SD card and doing a wipe and factory reset:

twrp-3.0.1-0-ovation.zip ( from: https://notredame.app.box.com/s/26a4bygh9vbaw7jjq08xr5evomvaw5ww/1/3332706778 )

lnos_ovation-ota-NOF26W.170226.zip (also from: https://notredame.app.box.com/s/26a4bygh9vbaw7jjq08xr5evomvaw5ww/1/3332706778 )

open_gapps-arm-7.1-pico-20170409.zip (from: http://opengapps.org/ )

I then choose the reboot option (I choose not to repair root, as some of these video apps detect root and won't play the videos). After the two stage boot which took a long time, the initial Android boot and setup took a really long time, but I had a working Play Store and could install what was needed.

Now for the quirks:

1) The WiFi seems to die overnight and I seem to need to reboot to get it back.

2) Can't seem to power it down -- Power Off seems to just reboot, as does Reboot (I'd hoped the labels were just reversed in the dialog).

3) Android 7 seems to be pushing the limits of the Nook HD+. Need to make sure any previous app is closed before starting a Video player app, otherwise I seem to often get pauses or "stutters". The new "square" button on the bottom of the display makes this easy.

Audio seems fine, especially over Bluetooth.

Again great job devs!!! I hope this info can help someone else, who like I did, easily gets lost in the 175+ pages of this thread and the turmoil of CM --> Linage OS.

Can some one explain the advantages/disadvantages of lnos builds vs. aosp builds? It was very unclear as to which I should choose so I basically flipped a coin :)

I'm not completely clear on the function of the "circle" in the middle of the "button row" on the bottom of the display. It seems to stop or pause things, is there a context dependency I've not figured out yet?