N9200 is a MP3 chip that provides serial ports, which perfectly integrates MP3 and WMV hard decoding chips. It includes two music modules: N9200A and N9200B. At the same time, the software supports the TF card drive, supports the content of the SPI Flash directly, and supports FAT16 and FAT32 file systems. Through simple UART serial instructions or one -line serial instructions, you can complete the specified music and how to play music. There is no need for cumbersome underlying operations, beautiful sound quality, convenient use, stable and reliable is the major feature of this product. In addition, this chip is also a deep -customized product, which is specially developed for the field of fixed voice playback fields.

★ Support sampling rate (kHz): 8/11.025/12/16/22.05/24/32/44.1/48. Beautiful sound quality and stereo;

★ 24 -bit DAC output, DSP hard decoding internally, non -PWM output, dynamic range support 90dB, signal -to -noise ratio supports 85DB;

★ Fully supports FAT16, FAT32 file system, supports the maximum TF card with a maximum 32G, and supports 32G U disk;

★ A variety of control mode, UART serial port mode, front -line serial port mode, AD key control mode;

★ Broadcast language insertion function can suspend the background music that is being played, support the playback of songs under the specified path, support cross -disk insertion, and support the end of the broadcast;

★ Play at the specified time;

★ Specify the player playback, specify the song playback;

★ The amount of level 30 can be adjusted, and 5 EQ can be adjusted (Normal — Pop — Rock — Jazz-Classic);

★ Specify path playback (support Chinese and English);

★ Folder switching;

★ Repeat reading at the specified time;

★ Support computer sound card control, support USBMass Storage;

★ Support triggering cannot be interrupted;

4.1, AdKey button control

The module we use is the method of AD keys, replacing the traditional matrix keyboard connection method. The advantage of this is to make full use of the more and more powerful AD function of the MCU. The design is simple and not simple. The module is configured with 2 AD ports and the resistance value of 10 keys. If you use it in the occasion of strong electromagnetic interference or strong sensual and capacity load, please refer to our "precautions".

(AdKey Reference Principles)

4.2, MCU first -line serial control mode

4.2.1, MCU front line serial port sequence

The first -line serial port MCU can only be controlled by one line. From the head size and the duty cycle, the low position is made, and the head code is pulled down 3ms above 3ms. It is usually kept high. A total of 8 bits. The timing occupation ratio is about 1: 3. The scope range is between 300US: 900US to 1000US: 3000US. The error allows 10%.