August 2020 ~ Scorpionz - Electronic Circuits and Microcontroller Projects

Previously I wrote a post about well-known voice module of DFPlayer Mini. Today I would like to write a post of advance chip, JQ8400. The main advantages of this chip are;

Inquiry of the file name
Inquiry of duration of the current audio
Inquiry of playback duration
Fast backward
Fast forward, etc.

Jq8400 Module

JQ8400 module is a SOC solution that combines a 16bit MCU with an ADSP specialized in audio decoding. By using hardware decoding method, it ensures system stability, quality of sound, and small footprint matching requirements of embedded applications. For the flexibility of R&D, control commands can be sent via one-line mode or RS232 serial communication.
It adopts full duplex serial communication protocol: Baud rate 9600, 8-bit data, no parity and 1 stop bit.

Message Format

Starting Code + Command Code + Data Length + Data 1 – Data n + Checksum

Starting Code: fixed as “AA” (in hex)
Command Code: 01 – 26 (in hex)
Data Length: respective data bytes in commands; length=1 stands for command only, no data.
Checksum: The low byte of the sum of all the bytes before the checksum byte.
Data format: high 8-bit first, low 8-bit second.

Communication Mechanism

Default power-on state is idle and listening for commands from MCU as a guest The module will not initiate communication and a MCU must take initiative. The TTL level of the serial port is 3.3V. Use a 1K ohm resistor if connecting with a 5V MCU.

Jq8400 Module Pin Details

Code

unsigned short df_wr[] = {0xAA,0,0,0,0,0};
void write_jq_cmd(char cmd, char data_h, char data_l, char len) //jq cmd data { char m;
Delay_ms(200);
       df_wr[1]= cmd;
       df_wr[2]= len;
       df_wr[3]= data_h;
       df_wr[4]= data_l;
       df_wr[5]= data_h + data_l + len + df_wr[1] + 0xAA;

    for (m=0; m<6; m++) {      Delay_ms(1);      if(len==0 && m==3) m=5; //(AA 02 00 AC) skip data_h data_l      if(len==1 && m==3) m=4; //(AA 18 01 03 C6) skip data_h      UART1_Write(df_wr[m]); //aa, cmd, len, dh, dl, sm    }    Delay_ms(10); }

Usage

write_jq_cmd(0x02, 0,0, 0); //Play write_jq_cmd(0x03, 0,0, 0); //Pause write_jq_cmd(0x13, 0,27, 1); //Set volume to 27 write_jq_cmd(0x07, 0x00,0xF4, 2); //Play 244th track write_jq_cmd(0x07, 0x01,0xF4, 2); //Play 500th track write_jq_cmd(0x23, 0x00,0x0A, 2); //FF 10 seconds