This tutorial shows you how to use an LM386 based audio amplifier with WTV020SD-16P module. The WTV020SD-16P music module has been configured in mp3 mode.
The following schematic shows the MP3 mode of WTV020SD module and it uses an LM386 based audio amplifier circuit also. This circuit works without an amplifier also, please check this article. For this project, you can make your own amplifier or buy a low cost LM386 amplifier module.
The schematic and its operation has been better explained on its product manual. I followed the schematic but I connected only RESET, PREV and NEXT switches only for this experiment.
a. Copy AD4 format music files on to your 2GB micro SD card. Download AD4 Format Files.
DOWNLOAD AD4 FORMAT FILES- SET2-SAMPLES FILES 2 (NEW!!! uploaded on 15.1.2014)
b. Connect the Audio amplifier, speaker, 3.3V regulator, switches and power supply.
Don’t forget to use a 0.1uF capacitor between Pin 2 of Audio module and the input pin of the amplifier. See the connections on the image given below. I used a 5V and a 3.3V regulators for this project. I noticed that the 3.3V regulator heats up heavily when connected to a 9V battery, so I connected the battery to a 5V regulator first and then to the 3.3V regulator. I used a 2GB microSD card for this experiment. If you use a 6V battery, you can connect the power supply straight to 3.3V regulator.
If this is your first experiment with WTV020SD-16P module, I strongly recommend you to read this article. The recommended article explains about the size of micro SD card and audio formats. The project works with a 2GB microSD card and AD4 format music files. Click here to know how to convert a wave or mp3 format files to AD4 format.
WATCH THE OUTPUT
- Photos on FLICKR
- Datasheet of WTV020SD-16P
- AD4 Format Files– Download Samples (6 music files)
- Photos on FLICKR
- Download SOMO tool for converting mp3 and wave files to AD4 format.
- Download AD4 sample files
- About WTV020SD-16P evaluation kit
You can buy all the components for this experiment on www.buildcircuit.net. The web store is owned and operated by buildcircuit.com. Buildcircuit.org is a reliable webstore for amateurs. It sells low cost components and offers fast shipping service.
- 3.3v regulator
- 5V regulator
- 2GB micro SD card
- Audio amplifier
- Tactile switch
DO NOT USE 5V POWER SUPPLY FOR THE MODULE. 5V will burn both your MicroSD card and WTV020SD module. Please use only 3.3V power, either from Arduino or use 3.3V regulator chip.
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