Hey Cube team, here's some code for stm32f4xx_hal_dac_ex.c

[Andrei Chichak]

Posted on February 25, 2015 at 00:41

/*
* For when you don't want a triangle wave or random noise.
*/
HAL_StatusTypeDef HAL_DACEx_NoWaveGenerate(DAC_HandleTypeDef* hdac, uint32_t Channel)
{
/* Check the parameters */
assert_param(IS_DAC_CHANNEL(Channel));
/* Process locked */
__HAL_LOCK(hdac);
/* Change DAC state */
hdac->State = HAL_DAC_STATE_BUSY;
/* Enable the selected wave generation for the selected DAC channel */
MODIFY_REG(hdac->Instance->CR, (DAC_CR_WAVE1) << 
Channel
, (DAC_WAVEGENERATION_NONE) << Channel);
/* Change DAC state */
hdac->State = HAL_DAC_STATE_READY;
/* Process unlocked */
__HAL_UNLOCK(hdac);
/* Return function status */
return HAL_OK;
}

[doreen]

Posted on May 06, 2015 at 19:27

Many users would provide their own data to the 12bit DAC so an example similar to the Escalator example for the 8bit DAC would have been nice.

The attached .jpg oscilloscope image shows about 20% of the data points not on the sine wave, by amplitude insufficient on PA4. Can anybody suggest a solution ?

Here are the modifications to main.c for DAC_SignalsGeneration for the stm32f429i_discovery board.

#define MAXNSINE 20

const uint16_t cSine12bit[MAXNSINE] = { 0x800,

0xa78,

0xcb3,

0xe78,

0xf9b,

0xfff,

0xf9b,

0xe78,

0xcb3,

0xa78,

0x800,

0x587,

0x34c,

0x187,

0x64,

0x0,

0x64,

0x187,

0x34c,

0x587

};

static void DAC_Ch1_SineConfig12bit(void)

{

/*##-1- Initialize the DAC peripheral ######################################*/

if(HAL_DAC_Init(&DacHandle) != HAL_OK)

{

/* Initialization Error */

Error_Handler();

}

/*##-2- DAC channel1 Configuration #########################################*/

sConfig.DAC_Trigger = DAC_TRIGGER_T6_TRGO;

sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;

if(HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DACx_CHANNEL1) != HAL_OK)

{

/* Channel configuration Error */

Error_Handler();

}

/* [dy] DMA the 12 bit SineWave data */

/*##-3- Enable DAC Channel1 and associated DMA #############################*/

if(HAL_DAC_Start_DMA(&DacHandle, DACx_CHANNEL1, (uint32_t*)cSine12bit, MAXNSINE, DAC_ALIGN_12B_R) != HAL_OK)

{

/* Start DMA Error */

Error_Handler();

}

}

Thanks for providing HAL_DACEx_NoWaveGenerate

________________

Attachments :

20150506_094020.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzQQ&d=%2Fa%2F0X0000000bMs%2FMIfKugJUkucPpZbQ5mMqP4PjdURFEP8PA4YqHA4MHpc&asPdf=false

[doreen]

Posted on May 07, 2015 at 00:13

The code changes below to stm32f4xx_hal_msp.c allows 12bit DAC of uint32_t sine_data

seen on PA4.

 

/* [dy] For 12bit example, this may break 8bit example

  hdma_dac1.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;

  hdma_dac1.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;

  */

  hdma_dac1.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;  

  hdma_dac1.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;