Posted on November 25, 2011 at 13:16Hi. This is the first time I write in this forum.
I must read 6 analog signals, 3 from an acelerometer and 3 from a gyroscope, every 20 ms. I am using PC1-PC3 and PA1-PA3 (STM32 Discovery VL), so this is my configuration code, programmed with Atollic True Studio (sorry for the extension):
void Configura_ADC(void)
{
ADC_InitTypeDef ADC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
// Se configuran los pines PA1 - PA3 y PC1 - PC3 como entradas anal�gicas
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_Init(GPIOC, &GPIO_InitStructure);
// Reloj para el ADC (max 14MHz --> 72/6=12MHz)
RCC_ADCCLKConfig (RCC_PCLK2_Div6);
// Habilita el sistema de reloj del ADC
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
// Configura el ADC
ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = ENABLE; // Conversi�n de m�ltiples canales
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE; // Modo de conversi�n cont�nua
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None; // Sin fuente de disparo para la conversi�n
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right; // Alineaci�n de los datos izquierda
ADC_InitStructure.ADC_NbrOfChannel = 6; // 6 canales de conversi�n (Ax, Ay, Az, Gr, Gp, Gy)
// Se asigna el canal y el orden de conversi�n
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 1, ADC_SampleTime_55Cycles5); // PA1 = ADC1_IN1
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 2, ADC_SampleTime_55Cycles5); // PA2 = ADC1_IN2
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 3, ADC_SampleTime_55Cycles5); // PA3 = ADC1_IN3
ADC_RegularChannelConfig(ADC1, ADC_Channel_11, 4, ADC_SampleTime_55Cycles5); // PC1 = ADC1_IN11 = Az
ADC_RegularChannelConfig(ADC1, ADC_Channel_12, 5, ADC_SampleTime_55Cycles5); // PC2 = ADC1_IN12 = Ax
ADC_RegularChannelConfig(ADC1, ADC_Channel_13, 6, ADC_SampleTime_55Cycles5); // PC3 = ADC1_IN13 = Ay
ADC_Init(ADC1, &ADC_InitStructure); // Inicia el ADC1
// Habilita el ADC
ADC_Cmd (ADC1,ENABLE);
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
// Calibraci�n del ADC (opcional, pero recomendado tras arrancar)
ADC_ResetCalibration(ADC1); // Resetea la calibraci�n previa
while(ADC_GetResetCalibrationStatus(ADC1));
ADC_StartCalibration(ADC1); // Inicia una nueva calibraci�n (el ADC debe estar OFF)
while(ADC_GetCalibrationStatus(ADC1));
}
I save the 6 signal measurements in a structure, like shows this function:
void Leer_mag(MEDIDA_AG * mag)
{
// uint16_t medidas[6];
uint8_t n = 0;
// CTE_CONVERSION = 3.3 Voltios / 2^12 niveles = 8.05664e-4
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_STRT) == RESET)
;
ADC_ClearFlag(ADC1, ADC_FLAG_STRT);
for(n = 0; n < 6; n++)
{
while(ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET)
;
ADC_ClearFlag(ADC1, ADC_FLAG_EOC);
//ADC_ClearFlag(ADC1, ADC_FLAG_EOC);
mag->medidas[n] = ADC_GetConversionValue(ADC1);
}
}
The problem is that when I check the value of the measurement with DAC and a multimeter, it seems it only reads one signal, not the 6 different signals. I have tried everithing. Must I use DMA or interruptions?
Thanks!!!
#adc-stm32-discovery
