The function of this module is up to four I2S signal inputs, select one of them to transmit to the following DAC decoder and other equipment! (Only one of the four channels can be selected for use, and the four channels cannot be combined into one channel). . .
This module is controlled by a single-chip microcomputer (the board has been integrated with a single-chip microcomputer and the program has been written, and the buyer does not need to use the single-chip control). The buyer only needs to connect an external button to choose which signal to use (note that the external button is without lock) Not a switch), and with power-off memory function (the signal selected last time will be used automatically when the machine is turned on next time). When one of the signals is used, the other three signals are completely blocked to avoid interference. Each signal can transmit up to 8 signal lines, except for the 4 used to transmit I2S signals, the remaining four can be used to transmit other signals, such as DSDON signal mute signals, etc. (Of course, the remaining four wires can also be used to transmit another set of I2S For four-channel use, you can freely play how to use it).
Detailed introduction:
The IN-A IN-B IN-C IN-D interface on the board is a four-channel signal input. The OUT interface is output. The But interface is used to switch the signal with an external button. The POWER (or + G) interface is a DC 5V supply voltage for the power interface.

You can set the board to select 1 for 2 ways, 1 for 3 ways, and 1 for 4 ways! The setting method is to press and hold the external button or short-circuit the But port and then power on the board to switch to the next mode! Switch to 2-channel mode in 4-channel mode, switch from 2-channel mode to 3-channel mode, and switch from 3-channel mode to 4-channel...Cyclic switching! ! !

It should be noted that when one of the signal lines such as D1 is used as a DATA data line, then D1 of all input and output interfaces must be used as DATA; the same is true for D2-D8.
Note: The GND of each board can only be connected to GND. D1-D8 cannot be used as GND! D1-D8 can only be connected to signals and cannot replace GND to connect to the front and rear boards! ! ! When connecting to the GND of the front and rear boards, only the GND pin can be used! ! ! ! !
The + of the power interface is connected to 5V G is connected to GND. Wrong connection will cause damage to the board!
When the But interface is connected to the button, the two wires of the button must be connected to the But interface, please do not lead from other places, and the two wires connected to the button cannot be connected to any other places, otherwise any problems will occur at your own risk!
The A B C D V 5 single-character interfaces on the board are used for connecting to the LED display (the new version of the V character is changed to 3.3V)! The connection method is as follows:

Note: The LED and other accessories need to be prepared by the buyer, and the LED is connected to 3.3V (the position of V in the above figure)!