@teastain2 OOB Out-Of-the-Box.
When you reset this unit, you get two on screen buttons: "Self Test", and "Into UI".
The Self Test does a wifi scan, lists all the APs it sees and then outputs: connecting to xinyuandianzi sprays lots of dots on the screen as it goes. On the battery device, this waits forever. On the USB-C powered device I get
Connection timed out, start smartconfig wait for smartconfig ... Please use EspTouch Apps to connect to distribution network.

Picking the Into UI button, I get a LilyGo logo animation, some sound then it displays 6 choices: Light, Controller, Wireless, Music, Mic FFT, and Configuration.
Light demos the LEDs, Controller shows some gauges which you can use with I/O inputs.
Music evidently can play music files... not sure how you get anything in there.
Mic FFT is some sort of Microphone test. This unit has a built in speaker and microphone.
The Configuration consists entirely of a button labeled Deep Sleep, which when pressed puts the Embed unit to sleep... which after you have a charged battery installed is useful.

It may be dependent on sensing a battery. I'm not repeatedly getting the animation on the battery powered device.
More experimentation is needed.

@teastain2 Thanks for the info. So far I have not setup the dev environment yet, I'm just working with the OOB units, adding a battery, memory chip, and case. I will continue to setup the remaining 4 units I have and see if a recognizable factor emerges.

Are the behaviors of the bootloader described somewhere?
Is it possible to configure your local wifi into the configuration?
Thanks,

@mphucul I'm having a similar problem. I got several units. One; all the demo function "work" including the Configuration; Deep Sleep button. Another, only the LED function, the others don't render anything on the screen, and the Configuration is missing.

I see a blue LED blinking next to the Groove connector. What does this indicate?