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External Codec vs Onboard Codec Configuration Differences STM32F4

Question asked by Palaima.Emmett on Jul 26, 2016
I am trying to configure an external audio codec to work with the STM32F4 discovery board. I have got the onboard codec working via the spi driver (stm32f4xx_spi.c) and was wondering how I would have to configure things differently so that the data would be sent to the external codec instead. As is it seems like I could connect my external codec to the necessary GPIO pins, but the internal codec would be connected to these as well which would cause problems. Is it a matter of simply changing the GPIO pins, or would there be something more? 

I use the following 2 methods to initialize codec control in my program:

void codec_init()
{


     GPIO_InitTypeDef PinInitStruct;
     GPIO_StructInit(&PinInitStruct);


     I2S_InitTypeDef I2S_InitType;


     I2C_InitTypeDef I2C_InitType;


     //Reset pin as GPIO
     PinInitStruct.GPIO_Pin = CODEC_RESET_PIN;
     PinInitStruct.GPIO_Mode = GPIO_Mode_OUT;
     PinInitStruct.GPIO_PuPd = GPIO_PuPd_DOWN;
     PinInitStruct.GPIO_OType = GPIO_OType_PP;
     PinInitStruct.GPIO_Speed = GPIO_Speed_50MHz;


     RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOD | RCC_AHB1Periph_GPIOB, ENABLE);


     GPIO_Init(GPIOD, &PinInitStruct);


     // I2C pins
     PinInitStruct.GPIO_Mode = GPIO_Mode_AF;
     PinInitStruct.GPIO_OType = GPIO_OType_OD;
     PinInitStruct.GPIO_Pin = I2C_SCL_PIN | I2C_SDA_PIN;
     PinInitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
     PinInitStruct.GPIO_Speed = GPIO_Speed_50MHz;
     GPIO_Init(GPIOB, &PinInitStruct);


     GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1);
     GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1);


     //enable I2S and I2C clocks
     //RCC_I2SCLKConfig(RCC_I2S2CLKSource_PLLI2S);
     RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1 | RCC_APB1Periph_SPI3, ENABLE);
     RCC_PLLI2SCmd(ENABLE);


     // I2S pins
     PinInitStruct.GPIO_OType = GPIO_OType_PP;
     PinInitStruct.GPIO_Pin = I2S3_SCLK_PIN | I2S3_SD_PIN | I2S3_MCLK_PIN;
     GPIO_Init(GPIOC, &PinInitStruct);


     PinInitStruct.GPIO_Pin = I2S3_WS_PIN;
     GPIO_Init(GPIOA, &PinInitStruct);


     //prepare output ports for alternate function
     GPIO_PinAFConfig(GPIOA, GPIO_PinSource4, GPIO_AF_SPI3);
     GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_SPI3);
     GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_SPI3);
     GPIO_PinAFConfig(GPIOC, GPIO_PinSource12, GPIO_AF_SPI3);




     //keep Codec off for now
     GPIO_ResetBits(GPIOD, CODEC_RESET_PIN);




     // configure I2S port
     SPI_I2S_DeInit(CODEC_I2S);
     I2S_InitType.I2S_AudioFreq = I2S_AudioFreq_48k;
     I2S_InitType.I2S_MCLKOutput = I2S_MCLKOutput_Enable;
     I2S_InitType.I2S_DataFormat = I2S_DataFormat_16b;
     I2S_InitType.I2S_Mode = I2S_Mode_MasterTx;
     I2S_InitType.I2S_Standard = I2S_Standard_Phillips;
     I2S_InitType.I2S_CPOL = I2S_CPOL_Low;


     I2S_Init(CODEC_I2S, &I2S_InitType);
     //I2S_Cmd(CODEC_I2S, ENABLE);




     // configure I2C port
     I2C_DeInit(CODEC_I2C);
     I2C_InitType.I2C_ClockSpeed = 100000;
     I2C_InitType.I2C_Mode = I2C_Mode_I2C;
     I2C_InitType.I2C_OwnAddress1 = CORE_I2C_ADDRESS;
     I2C_InitType.I2C_Ack = I2C_Ack_Enable;
     I2C_InitType.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
     I2C_InitType.I2C_DutyCycle = I2C_DutyCycle_2;


     I2C_Cmd(CODEC_I2C, ENABLE);
     I2C_Init(CODEC_I2C, &I2C_InitType);




}




void codec_ctrl_init()
{
     uint32_t delaycount;
     uint8_t CodecCommandBuffer[5];


     uint8_t regValue = 0xFF;


     GPIO_SetBits(GPIOD, CODEC_RESET_PIN);
     delaycount = 1000000;
     while (delaycount > 0)
     {
          delaycount--;
     }
     //keep codec OFF
     CodecCommandBuffer[0] = CODEC_MAP_PLAYBACK_CTRL1;
     CodecCommandBuffer[1] = 0x01;
     send_codec_ctrl(CodecCommandBuffer, 2);


     //begin initialization sequence (p. 32)
     CodecCommandBuffer[0] = 0x00;
     CodecCommandBuffer[1] = 0x99;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = 0x47;
     CodecCommandBuffer[1] = 0x80;
     send_codec_ctrl(CodecCommandBuffer, 2);


     regValue = read_codec_register(0x32);


     CodecCommandBuffer[0] = 0x32;
     CodecCommandBuffer[1] = regValue | 0x80;
     send_codec_ctrl(CodecCommandBuffer, 2);


     regValue = read_codec_register(0x32);


     CodecCommandBuffer[0] = 0x32;
     CodecCommandBuffer[1] = regValue & (~0x80);
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = 0x00;
     CodecCommandBuffer[1] = 0x00;
     send_codec_ctrl(CodecCommandBuffer, 2);
     //end of initialization sequence


     CodecCommandBuffer[0] = CODEC_MAP_PWR_CTRL2;
     CodecCommandBuffer[1] = 0xAF;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = CODEC_MAP_PLAYBACK_CTRL1;
     CodecCommandBuffer[1] = 0x70;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = CODEC_MAP_CLK_CTRL;
     CodecCommandBuffer[1] = 0x81; //auto detect clock
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = CODEC_MAP_IF_CTRL1;
     CodecCommandBuffer[1] = 0x07;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = 0x0A;
     CodecCommandBuffer[1] = 0x00;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = 0x27;
     CodecCommandBuffer[1] = 0x00;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = 0x1A | CODEC_MAPBYTE_INC;
     CodecCommandBuffer[1] = 0x0A;
     CodecCommandBuffer[2] = 0x0A;
     send_codec_ctrl(CodecCommandBuffer, 3);


     CodecCommandBuffer[0] = 0x1F;
     CodecCommandBuffer[1] = 0x0F;
     send_codec_ctrl(CodecCommandBuffer, 2);


     CodecCommandBuffer[0] = CODEC_MAP_PWR_CTRL1;
     CodecCommandBuffer[1] = 0x9E;
     send_codec_ctrl(CodecCommandBuffer, 2);


}

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