iRhythm Internet MP3 Radio

This appilcation is a prototype of Internet Radio designed on ARC EM Starter Kit,which could find music from online audition websites,like douban FM,Baidu FM,KuWo,Download mp3 file among the music,and decode them by using ARC DSP Instruction and optimized code for mp3 decode.By adding a I2S peripheral with a FPGA,song can be sent out and outputted from two speaker.

---

• Introduction
  • Function
  • System Architecture
  • Appearance
  • Video
• Hardware and Software Setup
  • Required Hardware
  • Required Software
  • Hardware Connection
• User Manual
  • Before Running This Application
  • Run This Application

---

Intruduction

iRhythm is a Internet Radio,which can download music from online audition websites,decompress the file and play,while the music file in SD card can also be decoded and played. With the help of a FPGA, the digital music data in SPI format can be converted into I2S format,which can be recognize by audio D/A convertor. Through an amplifier outside,the online music can be play out from two big speaker.And it's a really good feeling!

Function

• Online Music Crawling and Download
• Decode Mp3 file
• Protocol transit form SPI to I2S
• Power Amplification
• Performance data display

System Architecture

Appearance

• System Top View -- Control Part

• System Middle View -- Signal Processing Part

• System Bottom View -- Output Part

• System View

Video

iRhythm demo video

Hardware and Software Setup

---

Required Hardware

• Necessary Hardware:
  • DesignWare ARC EM Starter Kit(EMSK) *1
  • SD card *1
  • ESP8266 *1
  • Cmod A7 XC7A35T FPGA develop board *1
  • Pmod I2S *1
  • OLED(12864) *1
  • Headphone *1

• Additional Hardware:
  • Lipo Battery *1
  • Buck power regulator *2
  • Audio Amplifiers *1
  • Speaker *1

---

Required Software

• embarc_ops newest commit:976b8ed3b24b061df91f78bcc71a726dd2a63fae
• Metaware or ARC GNU Toolset
• Serial port terminal, such as putty, tera-term or minicom
• Any bitstream file can config your FPGA as a SPI to I2S protocol interface
• More than one MP3 file in SD card to avoid waiting while downloading

Hardware Connection

1. Insert your SD card with mp3 file in it.
2. Make sure all your module has been mounted on the board.
3. Make sure your power regulator connect is correct,including the voltage and polarity, or the prototype may be damaged
4. Connect your 3.5 inch Audio cable.
5. After all connector has been connected correctly,connect the Li-po battery to power up the design.

User Manual

Before Running This Application

• Download source code of iRhythm from github.
• Download ./doc/spi2i2s.bit,which is the bitstram file of Cmod A7 to extend a i2s peripherals
• Make sure all connection is correct again.
• Make sure iRhythm is in the Wifi environment,which is matching with the setting in the code,including wifi name and wifi password.
• Check the switch 1 and 2 of EMSK are in off state to boot as ARCem_7d core.

Run This Application

• Download with USB-JTAG or use bootloader to boot the program.
• After iRhythm connect the wifi,initialization will complete very fast and OLED may light to show the song reading from SD card.
• After that song can be heard from the speaker and OLED shows download speed and decode speed.If not,try to rotate the volume bar to increase the volume.
• the user can control with the key any time.

Makefile

• Selected FreeRTOS here, then you can use FreeRTOS API in your application:

# Selected OS
OS_SEL ?= freertos

• Target options about EMSK and toolchain:

 TOOLCHAIN=gnu
 BOARD=emsk
 BD_VER=23
 CUR_CORE=arcem7d

• The relative series of the root directory, here the path of the Makefile is ./embarc_osp/application/iRhythm/makefile:

   #
   # root dir of embARC
   #
   EMBARC_ROOT = ../..

• Directories of source files and header files, notice that it is not recursive:

   # application source dirs
   APPL_CSRC_DIR = ./src/GUI ./src/MUSIC ./src/MUSIC/mp3_dec ./src/MUSIC/mp3_dec/mp3_Ori ./src/MUSIC/mp3_dec/mp3_Dsp ./src/HW_ASSI ./src/NET ./src/NET/esp8266_wifi ./src/TASK
   APPL_ASMSRC_DIR = .

   # application include dirs
   APPL_INC_DIR = ./inc ./inc/mp3_dec
   APPL_DEFINES =

• Directories of Linker Script File,to use CCM

   # linker script file
   LINKER_SCRIPT_FILE ?= linker_file.ldf

See embARC Example User Guide, "Options to Hard-Code in the Application Makefile" for more detailed information about Makefile Options.

GUI

Placing the GUI source code in src/GUI folder. Placing the C source file.

folder/file	Function
gui.c	gui control reflash
key.c	key interrupt callback

HW_ASSI

Placing the HW_ASSI source code in src/HW_ASSI folder. Placing the C source file.

folder/file	Function
dma2spi.c	dma configuration for spi
iosignal.c	IO initialization
mem.c	SD file read

MUSIC

Placing the MUSIC source code in src/MUSIC folder. Placing the C source file.

folder/file	Function
mp3_dec/	walkgeek library for mp3 decode
filelist.c	api for link list control
mp3api.c	top lever Api of mp3 decode
music.c	music task top lever api

NET

Placing the NET source code in src/NET folder. Placing the C source file.

folder/file	Function
esp8266_wifi/	control api for ESP8266
net.c	api for net task

TASK

Placing the TASK source code in src/TASK folder. Placing the C source file.

folder/file	Function
GUI_task.c	main function of gui task
MUSIC_task.c	main function of mussic task
NET_task.c	main function of net task
main.c	start application

INCLUDE

Placing the INCLUDE source code in inc folder. Placing the HEADER source file.

folder/file	Function
mp3_dec	walkgeek library for mp3 decode
at_parser.h/esp8266.h	control api for ESP8266
include.h	all declaration of c file
perform.h/inc_task.h	api for debuging
FreeRTOSConfig.h	configuration of ROTS
ssd1306_app_config.h	configuration of u8glib

DSP

Placing the DSP source code in inc folder. Placing the HEADER source file.

folder/file	Function
Dsp_assembly.h	optimize code for Arc Dsp