void initial_opa(void) {
OPAMP_InitTypeDef OPAMP_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
//OPA1
OPAMP_InitStructure.OPAMP_NonInvertingInput = OPAMP_NonInvertingInput_IO4;
OPAMP_InitStructure.OPAMP_InvertingInput = OPAMP_InvertingInput_Vout;
OPAMP_Init(OPAMP_Selection_OPAMP1, &OPAMP_InitStructure);
OPAMP_PGAConfig(OPAMP_Selection_OPAMP1, OPAMP_OPAMP_PGAGain_2, OPAMP_PGAConnect_No);
//OPA2
OPAMP_InitStructure.OPAMP_NonInvertingInput = OPAMP_NonInvertingInput_IO3;
OPAMP_Init(OPAMP_Selection_OPAMP2, &OPAMP_InitStructure);
OPAMP_PGAConfig(OPAMP_Selection_OPAMP2, OPAMP_OPAMP_PGAGain_2, OPAMP_PGAConnect_No);
//OPA3
OPAMP_InitStructure.OPAMP_NonInvertingInput = OPAMP_NonInvertingInput_IO1;
OPAMP_Init(OPAMP_Selection_OPAMP3, &OPAMP_InitStructure);
OPAMP_PGAConfig(OPAMP_Selection_OPAMP3, OPAMP_OPAMP_PGAGain_2, OPAMP_PGAConnect_No);
//OPA4
OPAMP_InitStructure.OPAMP_NonInvertingInput = OPAMP_NonInvertingInput_IO1;
OPAMP_Init(OPAMP_Selection_OPAMP4, &OPAMP_InitStructure);
OPAMP_PGAConfig(OPAMP_Selection_OPAMP4, OPAMP_OPAMP_PGAGain_2, OPAMP_PGAConnect_No);
OPAMP_Cmd(OPAMP_Selection_OPAMP1, ENABLE);
OPAMP_Cmd(OPAMP_Selection_OPAMP2, ENABLE);
OPAMP_Cmd(OPAMP_Selection_OPAMP3, ENABLE);
OPAMP_Cmd(OPAMP_Selection_OPAMP4, ENABLE);
}
/**
* @brief OPAMP configuration.
* @param None
* @retval None
*/
static void OPAMP_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
OPAMP_InitTypeDef OPAMP_InitStructure;
/* GPIOA Peripheral clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
/* Configure OPAMP1 non inverting input IO1 (PA7)
and OPAMP1 Out (PA2) in analog mode */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Enable SYSCFG clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
/* Select Vout as inverting input (internal follower) for OPAMP1 */
OPAMP_InitStructure.OPAMP_InvertingInput = OPAMP_InvertingInput_Vout;
/* Select IO1 (PA7) as non inverting input for OPAMP1 */
OPAMP_InitStructure.OPAMP_NonInvertingInput = OPAMP_NonInvertingInput_IO1;
OPAMP_Init(OPAMP_Selection_OPAMP1, &OPAMP_InitStructure);
/* Enable OPAMP1 */
OPAMP_Cmd(OPAMP_Selection_OPAMP1, ENABLE);
}