Chinese menu MP3 song selector based on SC95F8616 microcontroller (2)

3.Key recognition

Since the key recognizes the low level of the corresponding scan, P07 is set to output a low level.

1 ) Complete the program flow modification as shown in Figure 16 and make corresponding configuration modifications.

Figure 16  Program flow

Figure 17  Modify configuration

2 ) Click  “ Generate Project Source Code ” to generate the project code ,  and its main program is shown in Figure 18 .

Figure 18  Generated main program

3 ) After compiling and downloading the program, press the K1~K4 keys in sequence, and the output result is shown in Figure 19 .

Figure 19  Key value output

4.MP3 audio module control

The MP3 audio module is a functional module controlled by serial communication. It can achieve the purpose of selection and control by cooperating with buttons.

The main commands for controlling MP3 are: play command, stop command and volume adjustment command. For easy control, they can be placed in array variables.

1 ) Add an array variable to store instructions

2 ) Add playback processing function

3 ) Complete the program flow modification as shown in  Figure 20 and reconfigure as shown in Figure 21 .

Figure 20 Program flow

Figure 21  Update related configuration

4 ) After compilation, the result is shown in Figure 22

Figure 22 Compilation results

5 ) After downloading the program, press K1 , K2 , and K3 keys in sequence to play, stop, and adjust the volume of the song respectively. The output content is shown in Figure 23 .

When the MP3 player module is connected , the control effect can be heard.

Figure 23 Operation effect