STM32 reads the data value of biaxial remote sensing

One . brief introduction

In terms of key control , Remote sensing with two axis buttons is far more convenient than buttons , And it's very easy to use . It consists of three data pins , Namely X Analog input of shaft ,Y Analog input and key input of axis , There's another one GND and VCC. here VCC Is a reference voltage , Can connect 5V, You can also pick up 3.3V. If the answer is 5V Words , that X The analog input voltage of the shaft is 0-5V.

Two . STM32 Read biaxial remote sensing data

Because the input is an analog value , So we need to use ADC Conduct analog acquisition . You can know from the data book that ,ADC Is the additional function of its pin , Reuse configuration is not required . Only need to GPIO_Mode configure AN that will do , Then configure ADC Relevant information is ok .

1. GPIO initialization

/*GPIO Init*/
void XYRocker1GPIOInit(void)
{
    
    GPIO_InitTypeDef GPIO_InitStruct;
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE);

    /*XY GPIO*/
    GPIO_InitStruct.GPIO_Pin   = GPIO_Pin_0 | GPIO_Pin_1;
    GPIO_InitStruct.GPIO_Mode  = GPIO_Mode_AN;  /" Additional features "/
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
	GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA,&GPIO_InitStruct);
    
    /*rocker key  Button for dual axis remote sensing */   
    GPIO_InitStruct.GPIO_Pin   = GPIO_Pin_12;
    GPIO_InitStruct.GPIO_Mode  = GPIO_Mode_IN;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB,&GPIO_InitStruct);
}

2. ADC initialization

void XYRockerADCInit(uint8_t num)
{
    
    ADC_InitTypeDef     ADC_InitStruct;
    ADC_CommonInitTypeDef  ADC_ComminInitStruct;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1,ENABLE);
    ADC_DeInit();
	
    ADC_ComminInitStruct.ADC_Mode                = ADC_Mode_Independent;
    ADC_ComminInitStruct.ADC_TwoSamplingDelay    = ADC_TwoSamplingDelay_20Cycles;
    ADC_ComminInitStruct.ADC_DMAAccessMode       = ADC_DMAAccessMode_Disabled;
    ADC_ComminInitStruct.ADC_Prescaler           = ADC_Prescaler_Div4;
    ADC_CommonInit(&ADC_ComminInitStruct);


    ADC_InitStruct.ADC_Resolution           = ADC_Resolution_12b;
    ADC_InitStruct.ADC_ScanConvMode         = DISABLE;
    ADC_InitStruct.ADC_ContinuousConvMode   = DISABLE;
    ADC_InitStruct.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
    ADC_InitStruct.ADC_DataAlign 			= ADC_DataAlign_Right;// Right alignment 
    ADC_InitStruct.ADC_NbrOfConversion      = num; 
    /* Dual axis has two analog inputs , So this is set to 2, If it is two remote sensing , Use the same ADC Words , I'm going to set it to 4*/
    
    ADC_Init(ADC1,&ADC_InitStruct);

	
	ADC_Cmd(ADC1,ENABLE);
}

3. data fetch

uint16_t getX1Value()
{
    
/* Set the channel for conversion */
    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_480Cycles );	
	ADC_SoftwareStartConv(ADC1);		// Enable to designate ADC1 Software conversion start function  
	while(!ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC ));// Wait for the conversion to finish 
	return ADC_GetConversionValue(ADC1);	// Go back to the last time ADC1 Conversion result of rule group 
}

After a few steps above , You can read the two axis remote sensing .
Reset status value is 2200 about . When biaxial remote sensing goes up, it is only 0 about , When down , Namely 4096 Around the （16bit 0-4096）. The same is true in the left and right directions . Its actual voltage value , Will be 0-4096 Mapping to 0-VCC Come on (VCC It is the voltage value you connect it ).
It's very good to control the flight control or car , Let's try ！
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