Ok, I made this because I keep seeing things posted about the the Nextion not working.. What it does is uses a slider to dim the screen, is shows the dim level and changes the default dim level.. it also stores and reads the last dim level value to EEPROM so it will restore to your last value.. If you use your imagination you could use a small piece of code like this to grab the value and use it on your arduino :-).. Look in the Nextion Arduino Library Examples
uint32_t number; n0.getValue(&number);
I love this display it has saved me so much time and trouble and am happy that I was able to donate on indiegogo to help get it going.. When I see complaining about the display not working because of lack of user knowledge its annoying. If something does not seem to be working its most likely your code. Im a user just like most on here and if you just post in the proper location most users will try to help out.
What you need to know is posted Here: http://wiki.iteadstudio.com/Nextion_Instruction_Set
It is good to see an example of using the EEPROM.
When the 1K gets close to depletion, just note:
dim command changes brightness for this session (does not survive a reboot)
dims command sets brightness for session and stores (will survive a reboot)
similarly, baud vs bauds.