Help with I2S in STM32F4 Discovery

Palacios.Bruno · ‎2013-03-30

Posted on March 30, 2013 at 22:39

Hello guys,

I have problems trying to interfacing the stm32f4 with the CS43L22 by the I2S protocol. I was able to set up and send the configurations words by I2C and see the handshaking between those with my oscilloscope, but I can't do the same with the I2S prot. So Im pretty sure that there is an error in my code. So please help me!

Here is my config code:

void I2S_LowLevel_Init(){

GPIO_InitTypeDef GPIO_InitStruct;

I2S_InitTypeDef I2S_InitStruct;

I2S_StructInit(&I2S_InitStruct); /* Inicializo estructura */

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);

RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE);

/* CODEC_I2S pins configuration: WS, SCK and SD pins -----------------------------

* I2S3_SCK = PC10

* I2S3_SD = PC12

* I2S3_MCLK = PC7

*/

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_10 | GPIO_Pin_12;

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOC, &GPIO_InitStruct);

/* Connect pins to I2S peripheral */

GPIO_PinAFConfig(GPIOC, GPIO_Pin_7, GPIO_AF_SPI3);

GPIO_PinAFConfig(GPIOC, GPIO_Pin_10, GPIO_AF_SPI3);

GPIO_PinAFConfig(GPIOC, GPIO_Pin_12, GPIO_AF_SPI3);

/*******************************************************************/

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4;

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOA, &GPIO_InitStruct);

GPIO_PinAFConfig(GPIOA, GPIO_Pin_4, GPIO_AF_SPI3);//puerto, pines

// RCC_PLLI2SCmd(DISABLE);

// RCC_I2SCLKConfig(RCC_I2S2CLKSource_PLLI2S);

// RCC_PLLI2SCmd(ENABLE);

// RCC_GetFlagStatus(RCC_FLAG_PLLI2SRDY);

I2S_InitTypeDef I2S_InitType;

I2S_InitType.I2S_AudioFreq = I2S_AudioFreq_44k;

I2S_InitType.I2S_MCLKOutput = I2S_MCLKOutput_Enable;

I2S_InitType.I2S_Mode = I2S_Mode_MasterTx;

I2S_InitType.I2S_DataFormat = I2S_DataFormat_16b;

I2S_InitType.I2S_Standard = I2S_Standard_Phillips;

I2S_InitType.I2S_CPOL = I2S_CPOL_Low;

I2S_Init(SPI3, &I2S_InitType);

I2S_Cmd(SPI3, ENABLE);

}

I couldn't configure the I2S3_MCLK pin either. Sorry for my english and thanks for all!

Best regards,

Bruno

#i2s #stm32f4-discovery

Tesla DeLorean · ‎2013-03-30

Posted on March 31, 2013 at 00:06

GPIO_PinAFConfig(GPIOC, GPIO_Pin_7, GPIO_AF_SPI3);

These need the PinSource form (an index), rather than the Pin form (a bit mask)

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Palacios.Bruno · ‎2013-03-30

Posted on March 31, 2013 at 00:54

Thanks clive1, but still not working... I don't know if its a problem with the MCLK config or what, this is the config

void I2S_LowLevel_Init(){

GPIO_InitTypeDef GPIO_InitStruct;

I2S_InitTypeDef I2S_InitStruct;

I2S_StructInit(&I2S_InitStruct); /* Inicializo estructura */

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE);

/* Connect pins to I2S peripheral */

GPIO_PinAFConfig(GPIOA, GPIO_PinSource4, GPIO_AF_SPI3);//puerto, pines

GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_SPI3);

GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_SPI3);

GPIO_PinAFConfig(GPIOC, GPIO_PinSource12, GPIO_AF_SPI3);

/* CODEC_I2S pins configuration: WS, SCK and SD pins -----------------------------

* I2S3_SCK = PC10

* I2S3_SD = PC12

* I2S3_MCLK = PC7

*/

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_10 | GPIO_Pin_12;

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOC, &GPIO_InitStruct);

/*******************************************************************/

GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4;

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOA, &GPIO_InitStruct);

I2S_StructInit(&I2S_InitStruct);

I2S_InitStruct.I2S_AudioFreq = I2S_AudioFreq_44k;

I2S_InitStruct.I2S_MCLKOutput = I2S_MCLKOutput_Enable;

I2S_InitStruct.I2S_Mode = I2S_Mode_MasterTx;

I2S_InitStruct.I2S_DataFormat = I2S_DataFormat_16b;

I2S_InitStruct.I2S_Standard = I2S_Standard_Phillips;

I2S_InitStruct.I2S_CPOL = I2S_CPOL_Low;

I2S_Init(SPI3, &I2S_InitStruct);

I2S_Cmd(SPI3, ENABLE);

RCC_PLLI2SCmd(DISABLE);

RCC_I2SCLKConfig(RCC_I2S2CLKSource_PLLI2S);

RCC_PLLI2SCmd(ENABLE);

RCC_GetFlagStatus(RCC_FLAG_PLLI2SRDY);

}

and in the main code I do:

InitGPIO();

I2C_LowLevel_Init();

I2S_LowLevel_Init();

GPIO_WriteBit(GPIOD, GPIO_Pin_4, Bit_RESET); //Reseteo DAC

Delay(0x4FFF);

GPIO_WriteBit(GPIOD, GPIO_Pin_4, Bit_SET);

Codec_Init();

while(1){

SPI_I2S_SendData(SPI3, 0xaaaa);

while (SPI_I2S_GetFlagStatus(SPI3, SPI_FLAG_TXE)== RESET);

}

I don't know if the I2S3_MCK (PC7) is well configured. I think that is not because I can't see nothing in this pin... The value 0xaaaa is just dummy.

Thank you again and regards!

waclawek.jan · ‎2013-04-04

Posted on April 04, 2013 at 11:26

RCC_APB1PeriphResetCmd(RCC_APB1Periph_SPI3, ENABLE);

should be

RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);

I understand that you've copied this from the ''documentation'' to the ''library'' - well, this is not the only flaw it has. Please let ST know, perhaps through https://my.st.com/onlinesupport/app?page=onlineSupport .

JW

PS. Clive must have been very tired when looking at this - this is exactly the type of errors he spots immediately... 🙂