This project is based at following templates from Espressif:
ESP8266_MP3_DECODER https://github.com/espressif/ESP8266_MP3_DECODER.git
ESP8266_RTOS_SDK https://github.com/espressif/ESP8266_RTOS_SDK.git
The project provides a WLAN radio, based on an ESP8266-chip. Audio-playback is streamed by use of the I2S-interface and an external I2S-DAC-chip. All settings (stream-URL, stream-Port, WLAN-settings) are adjustable by an integrated HTML-server.
In chapter/folder “Hardware” you can find information about used hardware for this project.
Inside the project there are also CAD-file for a housing (see chapter “CAD” below) and simulation-files for calculating crossover network-components (see chapter “Boxsim” below).
##Hardware As esp-board I used following NodeMCU-Board: https://github.com/nodemcu/nodemcu-devkit-v1.0
It has a esp12e-board integrated, but this code runs on a esp12f-board as well (other boards will also run, but I only tested esp12e and esp12f-boards). Some users tested a esp12-board without success!!!! For MP3-decoding a chip called PCM5102 is used. There are many cheep breakout-boards available. To select a stream-channel, a potentiometer is used. I used a linear potentiometer but a standard one is also fine. All other used components are optional and can be replaced or removed depending of your project!
Following there is a list of all used components: Controller:
- NodeMCU-board https://github.com/nodemcu/nodemcu-devkit-v1.0
- PCM5102 breakout-board http://www.ebay.com/itm/Assembled-Board-PCM5102-DAC-Decoder-I2S-Player-32bit-384K-Beyond-ES9023-PCM1794-/311402292006
All following components are optional. They are used in my radio, but if you like to implement this code into your system, you might need other / less components
Amplifier:
- DROK® TA2024B amplifier-board https://www.amazon.com/DROK-Computer-Amplifier-Electric-Capacity/dp/B00C03YYCK/ref=sr_1_1?ie=UTF8&qid=1476053365&sr=8-1&keywords=DROK%C2%AE+TA2024B
Stream-Change:
- Linear potentiometer 10K mono http://www.ebay.com/itm/ALPS-Schieberegler-RSA0N12-Schiebeweg-100mm-Potentiometer-Poti-Fader-/260967189845?var=&hash=item3cc2db4d55:m:mypFES_1KwCYSBZHzkEIXgg
Power-supply:
- Salcar Power-Supply 12V 3A 36W https://www.amazon.de/gp/product/B00LFB4GC6/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
- Mini DC-DC step down converter http://www.ebay.com/itm/10pcs-Mini-360-DC-DC-4-75V-23V-to-1V-17V-Buck-Converter-Step-Down-Power-supply-/272362239425?hash=item3f6a0df5c1:g:FZcAAOSw9IpXyY1d
- Slide-Switch 2-way (for disconnecting power-supply from NodeMCU in case of USB-connection)
- Connector for power supply C6 inclusive power-switch http://www.conrad-electronic.co.uk/ce/en/product/718564/IEC-connector-C6-Plug-horizontal-mount-Total-number-of-pins-2-PE-25-A-Black-1-pcs?ref=searchDetail
Bluetooth-connection:
Speaker
- Monacor SP40 https://www.monacor.com/de-de/monacorinternational/marken/monacor/beschallungstechnik/lautsprechertechnik/hi-fi-breitbandlautsprecher/sp-40/
- Dayton ND20FA http://www.daytonaudio.com/index.php/nd20fa-6-3-4-neodymium-dome-tweeter.html
Crossover Network
- Mundorf air coil L100, 2,2 mH/0,83 Ohm
- Mundorf air coil L71, 0,47 mH/0,57 Ohm
- Capacitor MKT 10,0 uF / 250Vdc
- Capacitor MKT 2,2 uF / 250Vdc
- Resistor MOX5 12 Ohm 2%
- Resistor MOX5 1,0 Ohm 2%
For a successful code-compiling following components are required:
Linux operation system (used for Project: Debian 9.0 Stretch, others should work as well). Also a virtual-machine should be fine.
esp-open-sdk: https://github.com/pfalcon/esp-open-sdk.git
gtkterm (optional, is used for reviewing serial output for debugging): Run following code in a terminal-window: sudo apt-get install gtkterm
-
Clone and compile esp-open-sdk like described in the repository.
-
Clone this repository to your local computer
-
Edit following file “<path_to_repository>/mp3/compile-script.sh” by using a standard-editor like gedit or notepad++. Following entries must be adjusted:
#-----------General settings ------------------- ESPTOOL_PATH=/home/christian/Dokumente/esp8266/esp-open-sdk/esptool/esptool.py CROSSCOMPILER_PATH=/home/christian/Dokumente/esp8266/esp-open-sdk/xtensa-lx106-elf/bin #-----------Project settings ------------------- #Keep PORT empty, to not flash the chip PORT=/dev/ttyUSB0 SDK_PATH=/home/christian/Dokumente/esp8266/myRadio PROJECT_PATH=$SDK_PATH/mp3 BIN_PATH=$SDK_PATH/bin BINARY_FILE_1=$BIN_PATH/eagle.flash.bin START_BYTE_1=0x00000 BINARY_FILE_2=$BIN_PATH/eagle.irom0text.bin START_BYTE_2=0x20000 UART_SPEED=115200 START_UART_AFTERWARDS=1Description:
ESPTOOL_PATH Path to esptool.py-file (used for flashing program at esp-chip) CROSSCOMPILER_PATH Path to cross-compiler (included in esp-open-sdk) PORT Link to Serial-Port, which is used for flashing esp-chip SDK_PATH Path to esp-open-sdk START_UART_AFTERWARDS Start gtkterm after successful code-compiling. If gtkterm is not available, set this parameter to 0All other values are project-related and should not be changed!
-
Connect esp-chip to computer
-
Start code-compiling and flashing by running scirpt “compile-script.sh” with root privilegs: sudo ./<path_to_repository>/mp3/compile-script.sh
##How to use Adjust settings by using html-server:
1. switch poti to total maximum value (end-position of poti)
2. After some seconds the esp-chip opens a wlan-hot-spot with SSID "myRadio" and no password.
3. Connect to this hotspot
4. Open your browser (google-chrome and firefox tested) and go to webside "http://192.168.4.1"
Following adjustments are possible:
WLAN-SSID SSID for your home-network
WLAN-Password Password to your home-network
Channel-count Number of stream-channels, which should be used+
For each channel:
Link to channel Link to stream-channel (without "http://")
Port to channel Port to stream-channel (often port 80)
Save to flash Save all settings to flash of esp-chip
5. To exit config-server-mode, select another channel by changing poti-position
6. Reboot device by refreshing homepage in browser or by disconnecting and connecting power-supply again
7. Ready!!
Selecting channel
Just use poti to select different channels...
Volume control
Volum has to be controlled by the amplifier, which is connected to PCM5102-device.
##CAD I designed a housing for my radio by using a web-CAD-service called OnShape:
Link to CAD-Software: https://www.onshape.com/
Link to project: https://cad.onshape.com/documents/0631abc9282a401a9c4bd0fe/w/ab4baf43f92f08b8f3445f90/e/15931d366a16f0a984bb5bd2
In folder "CAD" you can find all CAD-files and Drawings, which I created for this project. After building all parts by use of plywook, I used some fleece inside the speaker box to avoid oscilation of echo effects.
After assembling all parts together you will need an additional front-cover for the radio.
##Boxsim To get really good sound, I used two speakers in my project:
- Monacor SP40
- Dayton ND20FA
I also used a crossover network to optimize sound-quality. For simulation of the frequency-response of both speaker, I used an application called "Boxsim":
Link to homepage: http://www.boxsim.de/
Link to download: http://www.boxsim.de/download/Boxsim120en.zip
In folder called "Boxsim" you can find my Boxsim-project. To get a perfect sound, the frequency-response should be as straight as possible. In my project there is still a peak avalable at 5000Hz. The sound, which I get, sounds really great, but I can heard some small "scratches" if someone speaks. I don't know the reason for it. Maybe the esp-output is not perfect, some materials starts to oscilate, or the frequency-response is not perfect. But I am really happy with the sound, so I will not optimize it any more.