//main routine for ADC (linear) calibration testing
void TestADCCalibration(void)
{
unsigned int * ADCBuffer;
double * ADCRealValues;
double P, Q;
unsigned int i;
unsigned int NumOfData;
volatile double diffOrig;
volatile double diffCalib;
unsigned char DEBUG_STRING[30];
//set external clock (16MHz XTALL required)
SetCPUClock(0);
//allocate buffer space
if ((ADCBuffer = malloc(ADC_BUFFER_SIZE * sizeof(ADCBuffer[0]))) == NULL)
_asm("trap\n");
if ((ADCRealValues = malloc(ADC_BUFFER_SIZE * sizeof(ADCRealValues[0]))) == NULL)
_asm("trap\n");
//main test
{
//collect data
NumOfData = ADCCollectDataCalib(ADCBuffer, ADCRealValues);
P= GetMultiplierCalib(ADCBuffer, ADCRealValues, NumOfData);
diffOrig = GetErrorCalib(ADCBuffer, ADCRealValues, NumOfData, P, 0);
//calib data
ADCCalibratePQ(ADCBuffer, ADCRealValues, NumOfData, &P, &Q);
diffCalib = GetErrorCalib(ADCBuffer, ADCRealValues, NumOfData, P, Q);
//print errors
sprintf(DEBUG_STRING, "Orig = %f", diffOrig);
LCD_PrintString(LCD_LINE1, ENABLE, DISABLE, DEBUG_STRING);
sprintf(DEBUG_STRING, "Calib= %f", diffCalib);
LCD_PrintString(LCD_LINE2, ENABLE, DISABLE, DEBUG_STRING);
delay(500000l);//to show results
}
//see real values after ADC calibration - for checking calibration
LCD_Clear();
LCD_PrintString(LCD_LINE1, DISABLE, ENABLE, "Real calibrated U");
while(!JOY_SEL)
{
//start single conversion
ADC2_StartConversion();
while (!ADC2_GetFlagStatus());
//clear end of conversion bit
ADC2_ClearFlag();
//collect ADC value and display
LCD_SetCursorPos(LCD_LINE2, 4);//set cursor position
LCD_PrintDec4((P*ADC2_GetConversionValue() + Q)*1000);
}
//unallocate buffer
free(ADCBuffer);
}//TestADCCalibration
/**************************实现函数********************************************
*函数原型: unsigned int Get_ADCCH_Value(ADC2_Channel_TypeDef ADC_Channel)
*功 能: 单次采样某个ADC通道
*******************************************************************************/
unsigned int Get_ADCCH_Value(ADC2_Channel_TypeDef ADC_Channel)
{
unsigned int SUM = 0;//临时和
unsigned char j;
//配置ADC转换通道，单次采样模式，ADC结果右对齐
ADC2_Cmd(ENABLE);
ADC2_ConversionConfig(ADC2_CONVERSIONMODE_SINGLE, ADC_Channel, ADC2_ALIGN_RIGHT);
for (j = 0; j < 16 ; j++)
{
ADC2_StartConversion(); // 开始转换
while (ADC2_GetFlagStatus() == RESET); // 等待转换完成
SUM += ADC2_GetConversionValue(); // 求和
ADC2_ClearFlag();
}
SUM = SUM>>4;
ADC2_Cmd(DISABLE);
return(SUM);
}
//collection of ADC data and also real precise values from external voltmeter
//external data is entered with joystick movement as 0.000 number
static unsigned int ADCCollectDataCalib(unsigned int * ADCBuffer, double * ADCRealValues)
{
unsigned int i;
unsigned int multiplier;
signed int Voltage;
unsigned char cursorPos;
unsigned char ArrowChar = '^';
unsigned char JoyUp,JoyDown,JoyLeft,JoyRight,JoySel;
//disable ADC interrupts
ADC2_ITConfig(DISABLE);
//enable ADC
ADC2_Init(ADC2_CONVERSIONMODE_SINGLE, ADC2_CHANNEL_12, ADC2_PRESSEL_FCPU_D6, ADC2_EXTTRIG_TIM, DISABLE, ADC2_ALIGN_RIGHT, ADC2_SCHMITTTRIG_CHANNEL12, DISABLE);
//clear end of conversion bit
ADC2_ClearFlag();
//for joystick control (init)
//pull-ups on on all used buttons
GPIOB->CR1 |= 0xF0;
GPIOD->CR1 |= 0x80;
Voltage = 0;
multiplier = 1000;
cursorPos = 2;
//print values on LCD display
LCD_Clear();
LCD_SetCursorPos(LCD_LINE1, 1);
LCD_PrintDec4(Voltage);
LCD_PrintString(LCD_LINE1, DISABLE, ENABLE, " =Real U");
LCD_SetCursorPos(LCD_LINE2, cursorPos/2);
LCD_PrintChar(ArrowChar);
//set external voltage - measure it with external voltmeter - enter voltmeter
//value into LCD - measure ADC data - store real and ADC data to buffers
//finish data collecting by KEY button on PCB board
for(i=0; i<ADC_BUFFER_SIZE; i++)
{
LCD_SetCursorPos(LCD_LINE2, 0);
LCD_PrintDec2(i);
while(JOY_SEL);
while(!JOY_SEL)
{
if(BUTTON_LOW)
break;
JoyUp = JOY_UP;
JoyDown = JOY_DOWN;
JoyLeft = JOY_LEFT;
JoyRight= JOY_RIGHT;
JoySel = JOY_SEL;
if(JoyLeft)//increase multiplier
{
if (cursorPos!=2)
{
multiplier *= 10;
cursorPos -= 1;
}
}
if(JoyRight)//decrease multiplier
{
if (cursorPos!=5)
{
multiplier /= 10;
cursorPos += 1;
}
}
if(JoyRight || JoyLeft)//repaint cursor position
{
LCD_PrintString(LCD_LINE2, DISABLE, DISABLE, " ");//clear cursor
LCD_SetCursorPos(LCD_LINE2, cursorPos/2);//set cursor position
if(cursorPos & 1)
LCD_PrintChar(' ');//print space
LCD_PrintChar(ArrowChar);//print cursor
while (JOY_RIGHT || JOY_LEFT);
delay(1000l);
}
if(JoyUp)//increase real value
{
Voltage += multiplier;
}
if(JoyDown)//decrease real value
{
Voltage -= multiplier;
}
if(JoyUp || JoyDown)//repaint real value
{
LCD_PrintString(LCD_LINE1, DISABLE, DISABLE, " ");//clear voltage
if (Voltage<0)
{
LCD_SetCursorPos(LCD_LINE1, 1);
LCD_PrintDec4(-Voltage);
LCD_SetCursorPos(LCD_LINE1, 0);
LCD_PrintChar('-');//print sign
}
else
{
LCD_SetCursorPos(LCD_LINE1, 1);
LCD_PrintDec4(Voltage);
LCD_SetCursorPos(LCD_LINE1, 0);
LCD_PrintChar('+');//print sign
}
while (JOY_UP || JOY_DOWN);
delay(1000l);
}
//start single conversion
ADC2_StartConversion();
while (!ADC2_GetFlagStatus());
//clear end of conversion bit
ADC2_ClearFlag();
//collect ADC value and display it
LCD_SetCursorPos(LCD_LINE2, 5);//set cursor position
LCD_PrintDec4(ADC2_GetConversionValue());
}
//stop collecting if KEY buttom pressed
if(BUTTON_LOW)
{
break;
}
//otherwise collect ADC data (+ real data) and store them
else
{
//start single conversion
ADC2_StartConversion();
while (!ADC2_GetFlagStatus());
//clear end of conversion bit
ADC2_ClearFlag();
//collect ADC value
ADCBuffer[i] = ADC2_GetConversionValue();
//collect real value
ADCRealValues[i] = (double)Voltage/1000;
}
}
return i;
}//ADCCollectDataCalib