What's wrong with the grounding and GND in the circuit? How to connect?

There are three main "grounds" in the circuit. Power ground, signal ground, ground, Vcc or Vdd are connected to +5v, Gnd is grounded, and digital ground and analog ground are finally grounded. The circuit diagram generally does not indicate. And a vertical and a horizontal grounding means that the chassis is connected and there is no grounding.

GND is short for wire grounding. Represents the ground or neutral line. This ground is not a real ground, but an applied imaginary ground. For the power supply, it is the negative pole of the power supply.

Power supply mainly pays attention to the path taken by the current in the power supply loop. Generally speaking, the current flowing through the power ground is relatively large, and the signal is mainly concentrated on the path where the communication signal between two chips or modules flows back. Generally speaking, the current flowing through the signal ground is very small, but both are GND.

Extended data:

The purpose of grounding the signal circuit is:

Ensure that the signal has a stable reference potential. In order to make electronic equipment have a unified reference potential, avoid the interference of harmful electromagnetic fields, and make electronic equipment work stably and reliably, the signal circuit in electronic equipment should be grounded, which is called signal ground for short.

References:

Baidu encyclopedia -GND

References:

Baidu encyclopedia-grounding gas