使用STM32F4
我使用P3.0 （A12） 、 P3.2 (A14)、P3.3 (A15 ) 三个IO口，分别采三个ADC，但是都是以第一个采到的ADC的值为准，不会变化
P3.0采2.0V的电压，P3.2采0.5V的电压 P3.3采1.0V的电压，最后得到的结果总是以P3.0的值为准
但是单次分别采各自的电压是正确的，就是3个IO口一起采的时候，会出现这种情况。
请问是通道没有转换所以一直以第一个通道来采电压吗？还是有其他可能
请教大家，谢谢！
下面是ADC的初始化和采ADC函数代码
void init_adc()
{
//Initialize the ADC12B Module
/*
* Base address of ADC12B Module
* Use internal ADC12B bit as sample/hold signal to start conversion
* USE MODOSC 5MHZ Digital Oscillator as clock source
* Use default clock divider/pre-divider of 1
* Not use internal channel
*/
ADC12_B_initParam initParam = {0};
initParam.sampleHoldSignalSourceSelect = ADC12_B_SAMPLEHOLDSOURCE_SC;
initParam.clockSourceSelect = ADC12_B_CLOCKSOURCE_ADC12OSC;
initParam.clockSourceDivider = ADC12_B_CLOCKDIVIDER_1;
initParam.clockSourcePredivider = ADC12_B_CLOCKPREDIVIDER__1;
initParam.internalChannelMap = ADC12_B_NOINTCH;
ADC12_B_init(ADC12_B_BASE, &initParam);
//Enable the ADC12B module
ADC12_B_enable(ADC12_B_BASE);
/*
* Base address of ADC12B Module
* For memory buffers 0-7 sample/hold for 64 clock cycles
* For memory buffers 8-15 sample/hold for 4 clock cycles (default)
* Disable Multiple Sampling
*/
ADC12_B_setupSamplingTimer(ADC12_B_BASE, ADC12_B_CYCLEHOLD_16_CYCLES,
ADC12_B_CYCLEHOLD_4_CYCLES, ADC12_B_MULTIPLESAMPLESDISABLE);
//Configure Memory Buffer
/*
* Base address of the ADC12B Module
* Configure memory buffer 0
* Map input A3 to memory buffer 0
* Vref+ = AVcc
* Vref- = AVss
* Memory buffer 0 is not the end of a sequence
*/
ADC12_B_configureMemoryParam configureMemoryParam = {0};
configureMemoryParam.memoryBufferControlIndex = ADC12_B_MEMORY_0;
// configureMemoryParam.inputSourceSelect = ADC12_B_INPUT_A3;
configureMemoryParam.refVoltageSourceSelect =
ADC12_B_VREFPOS_AVCC_VREFNEG_VSS;
configureMemoryParam.endOfSequence = ADC12_B_NOTENDOFSEQUENCE;
configureMemoryParam.windowComparatorSelect =
ADC12_B_WINDOW_COMPARATOR_DISABLE;
configureMemoryParam.differentialModeSelect =
ADC12_B_DIFFERENTIAL_MODE_DISABLE;
ADC12_B_configureMemory(ADC12_B_BASE, &configureMemoryParam);
ADC12_B_clearInterrupt(ADC12_B_BASE, 0, ADC12_B_IFG0);
//Enable memory buffer 0 interrupt
ADC12_B_enableInterrupt(ADC12_B_BASE, ADC12_B_IE0, 0, 0);
} |
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