Posted on January 30, 2007 at 12:45I copied the program from the ST application note and I cannot get the ADC to give me a good reading. I basically have a DC voltage between 0.6 and 0.75 volts that I need to measure. I dont even need the 12 bit resolution, however when I run the ADC_12 I get a return value of either 0x95E or 0x6A1. Neither of which I believe since I change the input voltage and the results are the same. Additionally, the CSR reguister is always set as an overrun condition?
My code is below I am using the IAR workbench.
void ADC_init (void)
{
/* Configure the ADC analog input pin to High Impedance Analog Input */
GPIO_Config (GPIO1, AIN0, GPIO_HI_AIN_TRI);
/* Initialise the TIM0 registers */
// TIM_Init ( TIM0 );
/* Set TIM0 prescalar division factor to 0x0F */
// TIM_PrescalerConfig (TIM0, 0x0F);
/* Set the TIM0 counter to 0XFFFC */
// TIM_CounterConfig (TIM0, TIM_CLEAR);
/* Initialize the ADC Registers */
ADC12_Init();
/* Configure the ADC Prescaler */
ADC12_PrescalerConfig(1000);
}
int ADC_Convert()
{
#ifdef ADC_SINGLE
TIM_CounterConfig (TIM0, TIM_CLEAR);
/* Select the Single mode of conversion */
ADC12_ModeConfig (ADC12_SINGLE);
/* Select the channel to be converted */
ADC12_ChannelSelect(ADC12_CHANNEL0);
/* Enable the converter */
ADC12_ConversionStart();
/* Repeat until end of conversion */
ADC12_Clear();
ADC12_ConversionStart();
while (ADC12_FlagStatus (ADC12_DA0)==RESET);
ADC12_ConversionStop();
if( ADC12_FlagStatus (ADC12_OR) == RESET)
{
/* Get the Counter value */
Counter = TIM0->CNTR;
/* Read the conversion result*/
Conv_Res = ADC12_ConversionValue(ADC12_CHANNEL0);
}
#endif
/* Disable the Converter */
ADC12_ConversionStop();
return Conv_Res ;
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thank you
