swm181芯片 16位ADC转换误差为什么很大？

只看该作者 · 2023-4-14 10:27

void SerialInit(void);
void My_SDADC_Init_P(void)
{

SDADC_InitStructure SDADC_initStruct;

//GPIO_Init(GPIOC, PIN2, 0, 0, 0, 1);
  GPIO_Init(GPIOC, PIN4, 0, 0, 0, 1);

PORT_Init(PORTC, PIN4, PORTC_PIN4_SDADC_CH1P, 0); //PC.4 => SDADC.CH1P
//PORT_Init(PORTC, PIN2, PORTC_PIN2_SDADC_CH3P, 0); //PC.2 => SDADC.CH3P

SDADC_initStruct.clk_src = SDADC_CLKSRC_HRC_DIV8;
SDADC_initStruct.channels = SDADC_CH1 ;  //
SDADC_initStruct.out_cali = SDADC_OUT_CALIED;
SDADC_initStruct.refp_sel = SDADC_REFP_AVDD;//SDADC_REFP_AVDD  SDADC_OUT_CALIED
SDADC_initStruct.trig_src = SDADC_TRIGSRC_SW;
SDADC_initStruct.Continue = 0; //连续模式
SDADC_initStruct.EOC_IEn = 0;
SDADC_initStruct.OVF_IEn = 0;
SDADC_initStruct.HFULL_IEn = 0;
SDADC_initStruct.FULL_IEn = 0;
SDADC_Init(SDADC, &SDADC_initStruct); //配置SDADC

SDADC_Config_Set(SDADC, SDADC_CFG_A, SDADC_CFG_GAIN_1, 1, 1);
SDADC_Config_Cali(SDADC, SDADC_CFG_A, SDADC_CALI_COM_GND, 0);
SDADC_Config_Sel(SDADC, SDADC_CFG_A,  SDADC_CH1);

// SDADC_Config_Set(SDADC, SDADC_CFG_B, SDADC_CFG_GAIN_1, 1, 1);
//  SDADC_Config_Cali(SDADC, SDADC_CFG_B, SDADC_CALI_COM_GND, 0);
//  SDADC_Config_Sel(SDADC, SDADC_CFG_B, SDADC_CH3);

SDADC_Open(SDADC); //使能SDADC

}

int main(void)
{
int16_t res;
uint32_t i, chn;
SDADC_InitStructure SDADC_initStruct;

SystemInit();

SerialInit();

My_SDADC_Init_P(  );
// PORT_Init(PORTC, PIN6, PORTC_PIN6_SDADC_CH0P, 0); //PC.6 => SDADC.CH0P
// PORT_Init(PORTC, PIN7, PORTC_PIN7_SDADC_CH0N, 0); //PC.7 => SDADC.CH0N
//// PORT_Init(PORTC, PIN4, PORTC_PIN4_SDADC_CH1P, 0); //PC.4 => SDADC.CH1P
//// PORT_Init(PORTC, PIN5, PORTC_PIN5_SDADC_CH1N, 0); //PC.5 => SDADC.CH1N
//// PORT_Init(PORTC, PIN2, PORTC_PIN2_SDADC_CH3P, 0); //PC.2 => SDADC.CH3P
//// PORT_Init(PORTC, PIN3, PORTC_PIN3_SDADC_CH3N, 0); //PC.3 => SDADC.CH3N
//// PORT_Init(PORTD, PIN0, PORTD_PIN0_SDADC_CH4P, 0); //PD.0 => SDADC.CH4P
//// PORT_Init(PORTD, PIN1, PORTD_PIN1_SDADC_CH4N, 0); //PD.1 => SDADC.CH4N
//// PORT_Init(PORTB, PIN14,PORTB_PIN14_SDADC_CH5P,0); //PB.14=> SDADC.CH5P
//// PORT_Init(PORTB, PIN15,PORTB_PIN15_SDADC_CH5N,0); //PB.15=> SDADC.CH5N
////
//
// SDADC_initStruct.clk_src = SDADC_CLKSRC_HRC_DIV8;
// SDADC_initStruct.channels = SDADC_CH0;
// SDADC_initStruct.out_cali = SDADC_OUT_CALIED;
// SDADC_initStruct.refp_sel = SDADC_REFP_AVDD;
// SDADC_initStruct.trig_src = SDADC_TRIGSRC_SW;
// SDADC_initStruct.Continue = 0; //非连续模式，即单次模式
// SDADC_initStruct.EOC_IEn = 0;
// SDADC_initStruct.OVF_IEn = 0;
// SDADC_initStruct.HFULL_IEn = 0;
// SDADC_initStruct.FULL_IEn = 0;
// SDADC_Init(SDADC, &SDADC_initStruct); //配置SDADC
//
// SDADC_Config_Set(SDADC, SDADC_CFG_A, SDADC_CFG_GAIN_1, 1, 1);
// SDADC_Config_Cali(SDADC, SDADC_CFG_A, SDADC_CALI_COM_GND, 0);
// SDADC_Config_Sel(SDADC, SDADC_CFG_A, SDADC_CH0 | SDADC_CH1 | SDADC_CH2);
// SDADC_Config_Set(SDADC, SDADC_CFG_B, SDADC_CFG_GAIN_1, 0, 0);
// SDADC_Config_Cali(SDADC, SDADC_CFG_B, SDADC_CALI_COM_GND, 0);
// SDADC_Config_Sel(SDADC, SDADC_CFG_B, SDADC_CH3 | SDADC_CH4 | SDADC_CH5);
//
// SDADC_Open(SDADC); //使能SDADC

while(1==1)
{
SDADC_Start(SDADC);
while((SDADC->STAT & SDADC_STAT_EOC_Msk) == 0);
SDADC->STAT = 1 << SDADC_STAT_EOC_Pos;

res = SDADC_Read(SDADC, &chn);
res=res+0x8000;
res=(long int )res*3300/65536;
printf("%6d,", res);

for(i=0; i<800; i++); //此延时是必须的，缩短后可能导致SDADC不工作
}
}

void SerialInit(void)
{
UART_InitStructure UART_initStruct;

PORT_Init(PORTA, PIN0, FUNMUX_UART0_RXD, 1); //GPIOA.0配置为UART0输入引脚
PORT_Init(PORTA, PIN1, FUNMUX_UART0_TXD, 0); //GPIOA.1配置为UART0输出引脚

UART_initStruct.Baudrate = 57600;
UART_initStruct.DataBits = UART_DATA_8BIT;
UART_initStruct.Parity = UART_PARITY_NONE;
UART_initStruct.StopBits = UART_STOP_1BIT;
UART_initStruct.RXThresholdIEn = 0;
UART_initStruct.TXThresholdIEn = 0;
UART_initStruct.TimeoutIEn = 0;
UART_Init(UART0, &UART_initStruct);
UART_Open(UART0);
}

/******************************************************************************************************************************************
* 函数名称: fputc()
* 功能说明: printf()使用此函数完成实际的串口打印动作
* 输入: int ch 要打印的字符
* FILE *f 文件句柄
* 输出: 无
* 注意事项: 无
******************************************************************************************************************************************/
int fputc(int ch, FILE *f)
{
UART_WriteByte(UART0, ch);

while(UART_IsTXBusy(UART0));

return ch;
}

输入电压通过可调电阻分压再通过LM258运放跟随，送到PC4引脚采样。串口打印 1.195V ，万用表测1.151V. 不知道什么原因。