[N32L43x Review] DAC various waveform output tests

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[N32L43x Review] DAC various waveform output tests [Copy link]

Generally, DAC output is often used in analog signal control, which can control the output voltage of the op amp. This time we will mainly play with its output noise, sine wave, triangle wave, etc.

#include "dac.h"





void TIM4_TrgoInit(void);



void dac_channel_one_init()

{



 GPIO_InitType GPIO_InitStructure;

 DAC_InitType DAC_InitStructure;





 /* DAC Periph clock enable */

 RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_DAC, ENABLE);



 GPIO_InitStruct(&GPIO_InitStructure);

 /* GPIOA Periph clock enable */

 RCC_EnableAPB2PeriphClk(RCC_APB2_PERIPH_GPIOA, ENABLE);

 /* Once the DAC channel is enabled, the corresponding GPIO pin is automatically

 connected to the DAC converter. In order to avoid parasitic consumption,

 the GPIO pin should be configured in analog */

 GPIO_InitStructure.Pin = GPIO_PIN_4;

 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Input;

 GPIO_InitStructure.GPIO_Pull = GPIO_No_Pull;

 GPIO_InitPeripheral(GPIOA, &GPIO_InitStructure);



 /* DAC Channel Configuration */

 DAC_InitStructure.Trigger = DAC_TRG_NONE;

 DAC_InitStructure.WaveGen = DAC_WAVEGEN_NONE;

// DAC_InitStructure.LfsrUnMaskTriAmp = DAC_TRIAMP_2047;

 DAC_InitStructure.BufferOutput = DAC_BUFFOUTPUT_DISABLE;

 DAC_Init(&DAC_InitStructure);





 DAC_Enable(ENABLE);



// DAC_SetChData(DAC_ALIGN_R_12BIT,0x100);



// TIM4_TrgoInit();

// /* TIM4 enable counter */

// TIM_Enable(TIM4, ENABLE);

}



/**

* @brief TIM4 Init.

*/

void TIM4_TrgoInit(void)

{

 TIM_TimeBaseInitType TIM_TimeBaseStructure;



 /* TIM4 Periph clock enable */

 RCC_EnableAPB1PeriphClk(RCC_APB1_PERIPH_TIM4, ENABLE); // RCC_APB2_PERIPH_TIM8

 /* TIM4 Configuration */

 /* Time base configuration */

 TIM_InitTimBaseStruct(&TIM_TimeBaseStructure);

 TIM_TimeBaseStructure.Period = 0x08;

 TIM_TimeBaseStructure.Prescaler = 0x03;

 TIM_TimeBaseStructure.ClkDiv = 0x0;

 TIM_TimeBaseStructure.CntMode = TIM_CNT_MODE_UP;

 TIM_InitTimeBase(TIM4, &TIM_TimeBaseStructure);



 /* TIM4 TRGO selection */

 TIM_SelectOutputTrig(TIM4, TIM_TRGO_SRC_UPDATE);

}

This initialization code can be used in various tests later. First, look at the sine wave configuration above. I see that the routine is triggered by DMA+timer 4. Here we use it to directly output voltage plus sine function table to achieve it. This has a disadvantage, that is, there can only be this loop in while, and no more tasks will work.

uint16_t SinData[256]={2048, 2098, 2149, 2199, 2250, 2300, 2350, 2399, 2449, 2498, 2548, 2596, 2645, 2693, 2741, 2788, 2835, 2881, 2927, 2972, 3017, 3061, 3105, 3148, 3190, 3231, 3272, 3312, 3351, 3390, 3428, 3465, 3501, 3536, 3570, 3603, 3636, 3667, 3697, 3727, 3755, 3783, 3809, 3834, 3858, 3881, 3903, 3924, 3944, 3962, 3980, 3996, 4011, 4025, 4037, 4049, 4059, 4068, 4075, 4082, 4087, 4091, 4094, 4095, 4095, 4095, 4093, 4089, 4085, 4079, 4072, 4063, 4054, 4043, 4031, 4018, 4003, 3988, 3971, 3953, 3934, 3914, 3892, 3870, 3846, 3822, 3796, 3769, 3741, 3712, 3682, 3651, 3620, 3587, 3553, 3518, 3483, 3446, 3409, 3371, 3332, 3292, 3252, 3211, 3169, 3126, 3083, 3039, 2995, 2950, 2904, 2858, 2811, 2764, 2717, 2669, 2621, 2572, 2523, 2474, 2424,2375, 2325, 2275, 2224, 2174, 2124, 2073, 2023, 1972, 1922, 1872, 1821, 1771, 1721, 1672, 1622, 1573, 1524, 1475, 1427, 1379, 1332, 1285, 1238, 1192, 1146, 1101, 1057, 1013, 970, 927, 885, 844, 804, 764, 725, 687, 650, 613, 578, 543, 509, 476, 445, 414, 384, 355, 327, 300, 274, 250, 226, 204, 182, 162, 143, 125, 108, 93, 78, 65, 53, 42, 33, 24, 17, 11, 7, 3, 1, 0, 0, 2, 5, 9, 14, 21, 28, 37, 47, 59, 71, 85, 100, 116, 134, 152, 172, 193, 215, 238, 262, 287, 313, 341, 369, 399, 429, 460, 493, 526, 560, 595, 631, 668, 706, 745, 784, 824, 865, 906, 948, 991, 1035, 1079, 1124, 1169, 1215, 1261, 1308, 1355, 1403, 1451, 1500, 1548, 1598, 1647, 1697, 1746, 1796, 1846, 1897, 1947, 1998, 2048};

while(1)

{

 for(int x=0;x<sizeof(SinData)/sizeof(SinData[0]);x++){

 DAC_SetChData(DAC_ALIGN_R_12BIT,SinData[x]);

 }

}

The above code shows the test results as follows:

The triangle wave is to enable everything in the red box, and then the system can generate it by itself, using timer 4.

The modifications are as follows, and the test results are as follows:

 DAC_InitStructure.Trigger = DAC_TRG_T4_TRGO;

 DAC_InitStructure.WaveGen = DAC_WAVEGEN_TRIANGLE;

 DAC_InitStructure.LfsrUnMaskTriAmp = DAC_TRIAMP_2047;

The same is true for noise output. The modification is as follows, and the effect is as follows:

 DAC_InitStructure.Trigger = DAC_TRG_T4_TRGO;

 DAC_InitStructure.WaveGen = DAC_WAVEGEN_NOISE;

 DAC_InitStructure.LfsrUnMaskTriAmp = DAC_TRIAMP_2047;

I also tested its stability, and I still feel that the fluctuation is not particularly large. In the later use, I need to consider the internal temperature rise to see if there is any impact.

rgjinxuan

Thanks for sharing

[N32L43x Review] DAC various waveform output tests [Copy link]

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