Thermal Array Firmware update page:

Windows Software to install on your device XLoader Download.
Must have windows 7 or above to run the software.
Extract the software, once downloaded, the software does not require
installation. Once you extract double click on the folder and find the .exe file.  
Here is an example of the settings:
                               *First select where the .hex file is stored
                               *Make sure you select Duemilanove/Nano(ATmega328)
                               *Your com port may be different, when detected
                               *Make sure the Baud Rate is 57600, this works best
                               Then select Upload, you should getthe bytes uploaded if  
                               done properly, this means your upgraded, have fun!!!

Factory Installed Version as of April 1st, 2019

V1_20.Hex  (Currently Not Available for Download)
        Current Known Issues were working on:
             Battery Gauge not accurate, Incorrect percentage

V1.3.2.Hex New Shipments already have the latest software installed  this was
released April 6, 2019.
      Fixed the detection screen to stop double background
      Added New Feature the PS Mode (Powersaver) to increase battery life 2x
      Fixed freezes when display is in full brightness mode.