PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 1
PV198 – One-chip Controllers
Music Player
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 2
Content
1. Audio Codec
2. I2S
3. WAV file format
4. Application
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 3
Audio Codec
▪ Dialog Semiconductor – DA7212 – link
▪ 24-bit audio
▪ Low-power
▪ Beep generator – 2 Sine wave generators
▪ Bidirectional I2S
I2S Overview
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 4
▪ I2S – Inter-IC Sound – link to specification, Application
Note
▪ Serial bus for digital audio data in PCM format
▪ 3 signals:
▪ Serial clock (SCK)
▪ Word select (WS) / Frame sync (FS) – left/right channel select –
toggled after each sample
▪ Serial data (SD) – the data samples
I2S Overview
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 5
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WAV file format
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 6
▪ http://soundfile.sapp.org/doc/WaveFormat/
Application – Overview
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 7
▪ The application reads .wav files from the root folder of Micro SD card and
plays them via 3.5mm audio jack.
▪ Input:
▪ .wav file(s) in the root folder of Micro SD card
▪ Output:
▪ Analog sound via 3.5mm audio jack
▪ Limitations:
▪ Micro SD card must use FAT file system
▪ PCM format of .wav files is supported only
Application
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 8
▪ Peripherals used:
▪ I2S – for audio data transfer to audio codec
▪ SDHC – for SD card operations, e.g., .wav files read operation
▪ I2C – for audio codec configuration, e.g., sound bit-width, etc.
▪ PIT – for timing of tone generation
▪ Schematics: MCU CODEC
SD Headphones
SDHC
I2C
I2S (digital audio)
Application – Pins configuration
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 9
SD card
Console
CODEC
Application – Peripherals configuration
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 10
▪ SDHC – board example reused
▪ I2S – configured via Peripherals tool however the
peripheral properites (channels number, sample rate,
data width, and interrupts) are configured in the
application based on the .wav iles‘ properties
▪ PIT – configured via Peripherals tool
Application – Source Code
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 11
▪ Main loop:
▪ Configure the devices
▪ Start PIT to play tones sequence via I2C
▪ Start file reading, repeat the following sequence:
Fill the data read buffers
Wait until a buffer becomes empty after it is transmitted via I2S
▪ Interrupts:
▪ Used board demo I2C communication interrupts
▪ PIT uses interrupts for tones playing
▪ I2S uses interrupts for FIFO status notifications
Application
▪ Parse WAV file header and setup SAI and Codec format
correctly by implementing function:
▪ uint8_t processWavHeader(FIL* file)
PV198 – One-chip Controllers, Music Player / Dávid Danaj, Juraj Ondruška 12
Homework
 Update the project such: when all songs have been
played, it will start playing all again on repeat
PV198 – One-chip Controllers, LCD Display / Dávid Danaj, Marek Neužil 15