TrueSTUDIO 9.0.1 + STM32CubeMX + PCM5102 I2S DAC example

Download stm32 + pcm5102 example source code here (937kb)

Just made a quick test to connect PCM5102 module to STM32F407VET6 board through I2S interface.

First, I downloaded and installed latest version of CubeMX. I changed default position of I2S pins as shown on the image below:

First, audioBuffer array is filled with two sinusoidal tones of 1KHz and 2KHz. Then HAL_I2S_Transmit_DMA is called to run DMA transfer in circular mode.

#define AUDIO_BUFFER_SIZE 2048
__IO uint32_t audioBuffer[AUDIO_BUFFER_SIZE*2]; // stereo, size x 2

...

int i;
uint32_t tmp32;

for (i=0;i<AUDIO_BUFFER_SIZE;i++)
{

// 0xCCDDAABB
tmp32=0+10000000+round(10000000.0*sin(2.0*M_PI*2000/8000*i));
audioBuffer[i*2]=0;
audioBuffer[i*2]|=(tmp32 & 0x0000FFFF)<<16; // 0xAABB0000
audioBuffer[i*2]|=(tmp32 & 0xFFFF0000)>>16; // 0x0000CCDD

// 0xCCDDAABB
tmp32=0+10000000+round(10000000.0*sin(2.0*M_PI*1000/8000*i));
audioBuffer[i*2+1]=0;
audioBuffer[i*2+1]|=(tmp32 & 0x0000FFFF)<<16; // 0xAABB0000 audioBuffer[i*2+1]|=(tmp32 & 0xFFFF0000)>>16; // 0x0000CCDD
}
HAL_I2S_Transmit_DMA(&hi2s2, (uint16_t*)&audioBuffer, AUDIO_BUFFER_SIZE*2);

Although I2S configured as 32/32bit tranfer, I configured DMA transfer as halfword/halfword (16bit) to make it work correctly. It seems that there is a hint in STM’s Reference Manual:

The 24-bit and 32-bit data frames need two CPU read or write operations to/from the SPI_DR or two DMA operations if the DMA is preferred for the application. For 24-bit data frame specifically, the 8 nonsignificant bits are extended to 32 bits with 0-bits (by hardware)