Normally, I would think that the display can't light more, but I found that when the ESP32 is disconnected from PC and I leave only the LED matrix power connected (5V, 5A power supply) and touch the ground on disconnected ESP32, some random pixels on the display light up (random digital noise is displayed), but they light up much more. I left the display in the "error" state for over 24 hours to verify that the LEDs wouldn't overheat and destroy and everything was fine. Does anyone have any ideas how to get more brightness out of that display? It's obvious that it can do it, but I don't know what to change where to do it in the source code/library.
Below is an image of brightness at maximum RGB brightness and setBrightness8(255). And below that is the "error" state when I touch the ground of PC-disconnected ESP32 and the random pixels light up and are much brighter.
I don't think you can. As it seems, the microcontroller and the display work in multiplexing mode, and when you turn on the LED, it is brighter because they are static.
@majk33
The correct answer is a multiplexing, as mentioned by @flashko.
Your matrix has 1/16 scan, it means that it divided by 16 parts, switched one after another, so every pixel lit only 1/16 part of total time.
When you switch on the matrix without mcu, some random pixels lights statically and its brightness 16 times more than in normal mode.
Although it seems obvious to you that this is possible, it is not so.
I don’t want to upset you, but its brightness is unlikely to be significantly greater. You had the one with 16 scans and this one too... Although there may be different type of LEDs here...
In addition, I advise you to ask the seller about the type of driver that is used in the panel - not all outdoor panels are compatible with Arduino libraries
Unfortunately it is 1/16 too but I believe there are used different LEDs for outdoor panels or they are pulse overloaded to increase the brightness. Pulse overload should be safe for most LEDs. There is no documentation for this, the seller warns that it will arrive with different drivers every time "Different company led module or buy them at different time, they are not compatible", so I risked $40 that's not so much
I meant that the panel is already made in such a way that it itself uses pulse overloading to increase the brightness for outdoor purposes. If the manufacturer increased the brightness in this way, I will have to be careful not to leave the display in an "error" state to prevent the LEDs from overheating As soon as the panel arrives, I'll let you know how it turned out
As soon as the panel arrives, I'll let you know how it turned out 
