Stm32 ADC Voltage Test

1. stm32f103 ADC

In this example, the pa1 pin of the stm32f103 chip is used to test the analog input voltage value.

Article 31st, pin definition:

We know that pa1 uses adc1 Channel 1.

The Clock Tree is shown in the following figure:

Adc1 can be divided into 2, 4, 6, and 8, and the ADC input clock cannot exceed 14 MHz (see the stm32 reference manual rm0008 chapter 11th ADC ).

// Initialize the ADC // Here we only use the rule Channel as an example // We will enable the channel 0 ~ by default ~ 3 void adc_init (void) {adc_inittypedef adc_initstructure; gpio_inittypedef gpio_initstructure; enabled (enabled | enabled, enable); // enable adc1 channel clock rcc_adcclkconfig (Enabled ); // set the ADC frequency factor 6 72 m/6 = 12. The maximum ADC time cannot exceed 14 m // pa1 is used as the input pin of the analog channel gpio_initstructure.gpio_pin = gpio_pin_1; gpio_initstructure.gpio_mode = gpio; // simulate the Input Pin gpio_init (gpioa, & gpio_initstructure); adc_deinit (adc1); // reset adc1 and reset all registers of the peripheral adc1 to the default value adc_initstructure.adc_mode = adc_mode_independent; // ADC working mode: adc1 and adc2 work in standalone mode. adc_initstructure.adc_scanconvmode = Disable; // The module conversion works in single channel mode. adc_initstructure.adc_continuousconvmode = Disable; // modulus conversion works in a single conversion mode. Convert = adc_externaltrigconv_none; // The conversion is triggered by the software rather than the external start adc_initstructure.adc_dataalign = adc_dataalign_right; // The number of adc_init (adc1, & adc_initstructure) of the ADC channel for rule conversion in sequence; // initialize the adc_cmd (adc1, enable) Register of the peripheral adcx according to the parameter specified in adc_initstruct ); // enable the specified adc1 adc_resetcalibration (adc1); // enable the reset calibration while (adc_getresetcalibrationstatus (adc1); // wait until the reset calibration ends adc_startcalibration (adc1 ); // enable the ad calibration while (adc_getcalibrationstatus (adc1); // wait until the calibration ends adc_softwarestartconvcmd (adc1, enable); // enable the software conversion startup function of the specified adc1}

// Obtain the ADC value // CH: the channel value is 0 ~ 32010get_adc (u8 ch) {// set the channel of the specified ADC rule group, a sequence, the sampling time adc_regularchannelconfig (adc1, CH, 1, adc_sampletime_239cycles5); // adc1, ADC channel, the sampling time is 239.5 period adc_softwarestartconvcmd (adc1, enable); // enable the software conversion startup function of the specified adc1 while (! Adc_getflagstatus (adc1, adc_flag_eoc); // return adc_getconversionvalue (adc1) after the end of the conversion; // return the Conversion Result of the last adc1 rule group} 2010get_adc_average (u8 CH, u8 times) {u32 temp_val = 0; u8 t; for (t = 0; t <times; t ++) {temp_val + = get_adc (CH); delay_ms (5 );} return temp_val/times;} void adctask (void) {float vol, adcx; while (1) {adcx = get_adc_average (adc_channel_1, 10 ); // ADC value Vol = (float) adcx * (3300/4096); // voltage value (MV) delay_ms (200 );}}

2. stm32f407 ADC

In this example, the input voltage value is simulated using the pf9 pin of the stm32f407 chip.

Source Document: Page 43rd of stm32f4x7-datasheet.pdf, pin definition:

View STM32F4x7-Reference manual.pdf page 51st, memory ing:

Click the link to view the ADC register ing:

Also view the data register offset:

Know the data register address: # define adc3_dr_address (uint32_t) 0x4001224c)

View STM32F4x7-Reference manualtracing page 165th dma2 request mapping:

We know that dma2 stream0 Channel 2 is used to map to adc3.

#define ADC3_DR_ADDRESS    ((uint32_t)0x4001224C)__IO uint16_t ADC3ConvertedValue = 0;__IO uint32_t ADC3ConvertedVoltage = 0;//ADC3 channel07 with DMA configurationvoid ADC3_CH7_DMA_Config(void){  ADC_InitTypeDef       ADC_InitStructure;  ADC_CommonInitTypeDef ADC_CommonInitStructure;  DMA_InitTypeDef       DMA_InitStructure;  GPIO_InitTypeDef      GPIO_InitStructure;  /* Enable ADC3, DMA2 and GPIO clocks ****************************************/  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOF, ENABLE);  RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC3, ENABLE);  /* DMA2 Stream0 channel2 configuration **************************************/  DMA_InitStructure.DMA_Channel = DMA_Channel_2;    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC3_DR_ADDRESS;  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADC3ConvertedValue;  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;  DMA_InitStructure.DMA_BufferSize = 1;  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;  DMA_InitStructure.DMA_Priority = DMA_Priority_High;  DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;           DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;  DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;  DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;  DMA_Init(DMA2_Stream0, &DMA_InitStructure);  DMA_Cmd(DMA2_Stream0, ENABLE);  /* Configure ADC3 Channel7 pin as analog input ******************************/  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;  GPIO_Init(GPIOF, &GPIO_InitStructure);  /* ADC Common Init **********************************************************/  ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;  ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;  ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;  ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;  ADC_CommonInit(&ADC_CommonInitStructure);  /* ADC3 Init ****************************************************************/  ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;  ADC_InitStructure.ADC_ScanConvMode = DISABLE;  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;  ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T1_CC1;  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;  ADC_InitStructure.ADC_NbrOfConversion = 1;  ADC_Init(ADC3, &ADC_InitStructure);  /* ADC3 regular channel7 configuration *************************************/  ADC_RegularChannelConfig(ADC3, ADC_Channel_7, 1, ADC_SampleTime_3Cycles); /* Enable DMA request after last transfer (Single-ADC mode) */  ADC_DMARequestAfterLastTransferCmd(ADC3, ENABLE);  /* Enable ADC3 DMA */  ADC_DMACmd(ADC3, ENABLE);  /* Enable ADC3 */  ADC_Cmd(ADC3, ENABLE);}int main(void){  /* ADC3 configuration *******************************************************/  /*  - Enable peripheral clocks                                              */  /*  - DMA2_Stream0 channel2 configuration                                   */  /*  - Configure ADC Channel7 pin as analog input                             */  /*  - Configure ADC3 Channel7                                               */  ADC3_CH7_DMA_Config();  /* Start ADC3 Software Conversion */   ADC_SoftwareStartConv(ADC3);  while (1)  {    ADC3ConvertedVoltage = ADC3ConvertedValue *3300/0xFFF;

    delay_ms(200);  }}