Hello everyone,
I have designed a circuit that will be read 15 analog inputs. Because I use the STM32F042K6T6 as a MCU, I needed to use an analog MUX to read each inputs. I use the ADC peripheral with continuous conversion mode, 239.5 Cycles. And I have written a code to each inputs with 74HC4067 like following:
void Read_ADC_From_74HC4067(void)
{
for ( uint8_t z = 0; z <= 15; z += 1 )
{
//Z'nin degerine göre Kanal secimi yapilacak.
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT0_Pin, ( z >> 0) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT1_Pin, ( z >> 1) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT2_Pin, ( z >> 2) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT3_Pin, ( z >> 3) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
//Enable'i Low ve High yapip yukarida secilen kanali ortak çikisa aktariyor.
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT_EN_Pin, GPIO_PIN_RESET);
Temporary_ADC_Value[z] = HAL_ADC_GetValue(&hadc);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT_EN_Pin, GPIO_PIN_SET);
}
}
But the problem is that when I use this reading method, I face several problems such as wrong results. However, when I read a specific output by setting selecting pins like following, I have no problem.:
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT0_Pin, GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT1_Pin, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT2_Pin, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT3_Pin, GPIO_PIN_RESET);
//Enable'i Low ve High yapip yukarida secilen kanali ortak çikisa aktariyor.
Temporary_ADC_Value[z] = HAL_ADC_GetValue(&hadc);
It may be a problem about timing or something else? Could you please help me about this issue?
Thanks in advance.
I have designed a circuit that will be read 15 analog inputs. Because I use the STM32F042K6T6 as a MCU, I needed to use an analog MUX to read each inputs. I use the ADC peripheral with continuous conversion mode, 239.5 Cycles. And I have written a code to each inputs with 74HC4067 like following:
void Read_ADC_From_74HC4067(void)
{
for ( uint8_t z = 0; z <= 15; z += 1 )
{
//Z'nin degerine göre Kanal secimi yapilacak.
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT0_Pin, ( z >> 0) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT1_Pin, ( z >> 1) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT2_Pin, ( z >> 2) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT3_Pin, ( z >> 3) & 0x01 ? GPIO_PIN_SET : GPIO_PIN_RESET);
//Enable'i Low ve High yapip yukarida secilen kanali ortak çikisa aktariyor.
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT_EN_Pin, GPIO_PIN_RESET);
Temporary_ADC_Value[z] = HAL_ADC_GetValue(&hadc);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT_EN_Pin, GPIO_PIN_SET);
}
}
But the problem is that when I use this reading method, I face several problems such as wrong results. However, when I read a specific output by setting selecting pins like following, I have no problem.:
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT0_Pin, GPIO_PIN_RESET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT1_Pin, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT2_Pin, GPIO_PIN_SET);
HAL_GPIO_WritePin(GPIOA, ADC_CH_SELECT3_Pin, GPIO_PIN_RESET);
//Enable'i Low ve High yapip yukarida secilen kanali ortak çikisa aktariyor.
Temporary_ADC_Value[z] = HAL_ADC_GetValue(&hadc);
It may be a problem about timing or something else? Could you please help me about this issue?
Thanks in advance.