Dac Data Value To Voltage Correspondence; Dma Requests; Dac Hal Driver Macros List; How To Use This Driver - ST STM32F2 User Manual

UM1940

DAC data value to voltage correspondence

The analog output voltage on each DAC channel pin is determined by the following
equation: DAC_OUTx = VREF+ * DOR / 4095 with DOR is the Data Output Register VEF+
is the input voltage reference (refer to the device datasheet) e.g. To set DAC_OUT1 to
0.7V, use Assuming that VREF+ = 3.3V, DAC_OUT1 = (3.3 * 868) / 4095 = 0.7V

DMA requests

A DMA1 request can be generated when an external trigger (but not a software trigger)
occurs if DMA1 requests are enabled using HAL_DAC_Start_DMA()
DMA1 requests are mapped as following:
1. DAC channel1 : mapped on DMA1 Stream5 channel7 which must be already
configured
2. DAC channel2 : mapped on DMA1 Stream6 channel7 which must be already
configured For Dual mode and specific signal (Triangle and noise) generation please
refer to Extension Features Driver description
12.2.2

How to use this driver

DAC APB clock must be enabled to get write access to DAC registers using
HAL_DAC_Init()
Configure DAC_OUTx (DAC_OUT1: PA4, DAC_OUT2: PA5) in analog mode.
Configure the DAC channel using HAL_DAC_ConfigChannel() function.
Enable the DAC channel using HAL_DAC_Start() or HAL_DAC_Start_DMA functions
Polling mode IO operation
Start the DAC peripheral using HAL_DAC_Start()
To read the DAC last data output value, use the HAL_DAC_GetValue() function.
Stop the DAC peripheral using HAL_DAC_Stop()
DMA mode IO operation
Start the DAC peripheral using HAL_DAC_Start_DMA(), at this stage the user specify
the length of data to be transferred at each end of conversion
At The end of data transfer HAL_DAC_ConvCpltCallbackCh1()or
HAL_DAC_ConvCpltCallbackCh2() function is executed and user can add his own
code by customization of function pointer HAL_DAC_ConvCpltCallbackCh1 or
HAL_DAC_ConvCpltCallbackCh2
In case of transfer Error, HAL_DAC_ErrorCallbackCh1() function is executed and user
can add his own code by customization of function pointer
HAL_DAC_ErrorCallbackCh1
Stop the DAC peripheral using HAL_DAC_Stop_DMA()

DAC HAL driver macros list

Below the list of most used macros in DAC HAL driver.
__HAL_DAC_ENABLE : Enable the DAC peripheral
__HAL_DAC_DISABLE : Disable the DAC peripheral
__HAL_DAC_CLEAR_FLAG: Clear the DAC's pending flags
__HAL_DAC_GET_FLAG: Get the selected DAC's flag status
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HAL DAC Generic Driver
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