uBTIX Nextion Display and microSD card woes #ubitx


I just want to pass on some discoveries I made today while upgrading my uBTIX to run KD8CEC V1.094 with a 2.8' Nextion Display.

If you follow Ian's instructions at  (http://www.hamskey.com/2018/06/ubitx-with-nextion-lcd-cec-firmware.html#more) 
you need to download .TFT files and install the correct one, based on display size, onto a microSD card and plug that into the Nextion Display before powering it up.
This is required to load the KB8CEC GUI code into the display. 

I ran into some problems doing this so I want share what I have discovered so that you don't make the same mistakes that I did. 

1) The Display wants the microSD card to be formatted as FAT32.

What this means to you is that you can't use a microSD card larger than 32GB as the default in 
Windows is to format cards > 32 GB as exFAT, which the Nextion does not like. In fact Windows 10 wouldn't even let me reformat a card this big as FAT32.
(I am sure if you dig deep enough there might be a way to do this. I am not a Windows GURU).  

Currently you only need a 2 GB card so if you need to buy one for this purpose try an 8GB card. It is also worth it to buy a brand name card (like Sandisk).
One of the no-name cards that I have is slower than cold molasses to read from and write to. I ended up running out to the local drugstore for an 8GB 
Sandisk at 4pm as I realized all of the cards I had were either too big or duds. 

2) If you have a problematic microSD card, when you power up the rig you might not see anything on the display, not even a backlight !  

I spent considerable time trying to solve what I thought was a wiring/power problem to the display when it was a bad SD card. When the I removed the card and power-cycled the rig the 
Nextion display came up fine with a demo program that was already loaded.  So my recommendation is for the initial power up of the display don't insert the SD
card. That way you can be sure that you have it wired up ok before you start messing with SD cards. 

3) Beware, ground and +5V connections on the Raduino going to the Nextion Display are adjacent to each other. 
I recommend that you check and recheck your wiring several times before applying power.
It is very easy to accidentally swap these and you won't be happy if you do.  As they say, "An ounce of prevention is worth a pound of cure".
One group member has already found this out the hard way.


Michael VE3WMB 

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