Switching pin between ADC and General IO

[ebommer]

Posted on April 09, 2014 at 18:53

Hi All,

What I would like to do is when I receive a CAN bus message with data equal to ''12'' I will configure GPIOB Pin 0 to an Analog input, and when the data is 11 it will be reconfigured to an General purpose I/O. &sharpdefine ADC1_DR_Address    ((uint32_t)0x4001244C)__IO uint16_t ADCConvertedValue[5];  void Port_Config(void){  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);   RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_GPIOA| RCC_APB2Periph_GPIOB, ENABLE);  /* Configure PA.0,1,2,3 as analog input -------------------------*/  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;  GPIO_Init(GPIOA, &GPIO_InitStructure);/* Configure PB.0 as Output   -------------------------*/  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;  GPIO_Init(GPIOB, &GPIO_InitStructure);  /* DMA1 channel1 configuration -------------------------------*/  DMA_DeInit(DMA1_Channel1);  DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADCConvertedValue;  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;  DMA_InitStructure.DMA_BufferSize = 4;  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;  DMA_InitStructure.DMA_Priority = DMA_Priority_High;  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;  DMA_Init(DMA1_Channel1, &DMA_InitStructure);    /* Enable DMA1 channel1 */  DMA_Cmd(DMA1_Channel1, ENABLE);    /* ADC1 configuration -----------------------------------------*/  ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;  ADC_InitStructure.ADC_ScanConvMode = ENABLE;  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;  ADC_InitStructure.ADC_NbrOfChannel = 4;  ADC_Init(ADC1, &ADC_InitStructure);  /* ADC1 regular channel 00 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_55Cycles5);  /* ADC1 regular channel 01 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_55Cycles5);  /* ADC1 regular channel 02 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_55Cycles5);  /* ADC1 regular channel 03 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_55Cycles5);  /* Enable ADC1 DMA */  ADC_DMACmd(ADC1, ENABLE);    /* Enable ADC1 */  ADC_Cmd(ADC1, ENABLE);  /* Enable ADC1 reset calibration register */     ADC_ResetCalibration(ADC1);  /* Check the end of ADC1 reset calibration register */  while(ADC_GetResetCalibrationStatus(ADC1));  /* Start ADC1 calibration */  ADC_StartCalibration(ADC1);  /* Check the end of ADC1 calibration */  while(ADC_GetCalibrationStatus(ADC1));       /* Start ADC1 Software Conversion */   ADC_SoftwareStartConvCmd(ADC1, ENABLE);}So far in my attempts when I add an additional A/D, all of my conversions that used to work stop working.init main(void){ ......// if(CAN message = 11,  GPIOB Pin 0 conf. as an General Purpose I/O) case 11:                         /* Configure PB0 Out On */ GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitStructure);                         GPIO_WriteBit(GPIOB,GPIO_Pin_0,Bit_SET); CAN_AppTX.data[0] = 0x01;break;//if(CAN message = 12,  GPIOB Pin 0 configured as an analog Input) case 12:                         /* Configure PB0 A/D */                  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; GPIO_Init(GPIOB, &GPIO_InitStructure); ADC_InitStructure.ADC_NbrOfChannel = 5; ADC_Init(ADC1, &ADC_InitStructure);                      ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 5,  ADC_SampleTime_55Cycles5); ADC_Cmd(ADC1, ENABLE); ADC_SoftwareStartConvCmd(ADC1, ENABLE);                         DMA_InitStructure.DMA_BufferSize = 5; DMA_Init(DMA1_Channel1, &DMA_InitStructure); DMA_Cmd(DMA1_Channel1, ENABLE);........}Thank you for any help.   #stm32-adc

[Tesla DeLorean]

Posted on April 09, 2014 at 19:06

void Port_Config(int mode)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); 
ADC_DeInit(ADC1);
DMA_DeInit(DMA1_Channel1);
/* Configure PA.0,1,2,3 as analog input -------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Configure PB.0 as Output or Analogue -------------------------*/
if (mode == 11)
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* DMA1 channel1 configuration -------------------------------*/
DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADCConvertedValue;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = (mode == 11) ? 4 : 5;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel1, &DMA_InitStructure);
/* Enable DMA1 channel1 */
DMA_Cmd(DMA1_Channel1, ENABLE);
/* ADC1 configuration -----------------------------------------*/
ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode = ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel = (mode == 11) ? 4 : 5;
ADC_Init(ADC1, &ADC_InitStructure);
/* ADC1 regular channel 00 configuration */ 
ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_55Cycles5);
/* ADC1 regular channel 01 configuration */ 
ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_55Cycles5);
/* ADC1 regular channel 02 configuration */ 
ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_55Cycles5);
/* ADC1 regular channel 03 configuration */ 
ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_55Cycles5);
if (mode == 11)
ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 5, ADC_SampleTime_55Cycles5);
/* Enable ADC1 DMA */
ADC_DMACmd(ADC1, ENABLE);
/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
/* Enable ADC1 reset calibration register */ 
ADC_ResetCalibration(ADC1);
/* Check the end of ADC1 reset calibration register */
while(ADC_GetResetCalibrationStatus(ADC1));
/* Start ADC1 calibration */
ADC_StartCalibration(ADC1);
/* Check the end of ADC1 calibration */
while(ADC_GetCalibrationStatus(ADC1));
/* Start ADC1 Software Conversion */ 
ADC_SoftwareStartConvCmd(ADC1, ENABLE);
}

[ebommer]

Posted on April 09, 2014 at 19:24

Thanks clive1.

I didn't think about that, I could just call my port configuration function anytime I want to reconfigure my IO, even if its just changing a single pin.

[Tesla DeLorean]

Posted on April 09, 2014 at 19:54

I felt this would be a more robust and predictable method of switching over assuming you have the DMA/ADC at some random state when reconfiguring.

[ebommer]

Posted on April 09, 2014 at 21:20

I have added your suggestions and it works.  I am having a little strange behavior though.  

When I start up 

ADCConvertedValue[0] = GPIOA.Pin0,

ADCConvertedValue[1] = GPIOA.Pin1,ADCConvertedValue[2] = GPIOA.Pin2,ADCConvertedValue[3] = GPIOA.Pin3,after I reconfigure the port the assignment seems to change in the array.

ADCConvertedValue[0] = GPIOB.Pin0,

ADCConvertedValue[1] = GPIOA.Pin0,

ADCConvertedValue[2] = GPIOA.Pin1,

ADCConvertedValue[3] = GPIOA.Pin2,

ADCConvertedValue[3] = GPIOA.Pin3,

I would of expected GPIOB.Pin0 would be 

ADCConvertedValue[3] since the rank equal 5.

I am using the debugger in Keil over JTAG to monitor the array.  As a difference from your program suggestion I left the pin configuration in the main loop.From Main...GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;GPIO_Init(GPIOB, &GPIO_InitStructure);                    ADC_Config(8);CAN_AppTX.data[0] = 0x03;           void ADC_Config(unsigned char x){   

  /* DMA1 channel1 configuration ------------------------------------*/

  DMA_DeInit(DMA1_Channel1);  DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address;  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&ADCConvertedValue;  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;  DMA_InitStructure.DMA_BufferSize = (NumberOfAD == 4) ? 4 : 5;  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;  DMA_InitStructure.DMA_Priority = DMA_Priority_High;  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;  DMA_Init(DMA1_Channel1, &DMA_InitStructure);    /* Enable DMA1 channel1 */  DMA_Cmd(DMA1_Channel1, ENABLE);    /* ADC1 configuration ------------------------------------------*/  ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;  ADC_InitStructure.ADC_ScanConvMode = ENABLE;  ADC_InitStructure.ADC_ContinuousConvMode = ENABLE;  ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;  ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;  ADC_InitStructure.ADC_NbrOfChannel = (NumberOfAD == 4) ? 4 : 5;  ADC_Init(ADC1, &ADC_InitStructure);  /* ADC1 regular channel 00 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_55Cycles5);  /* ADC1 regular channel 01 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_55Cycles5);  /* ADC1 regular channel 02 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_55Cycles5);  /* ADC1 regular channel 03 configuration */   ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_55Cycles5);  if(NumberOfAD != 4)  {    ADC_RegularChannelConfig(ADC1, ADC_Channel_8, 5, ADC_SampleTime_55Cycles5);  }  /* Enable ADC1 DMA */  ADC_DMACmd(ADC1, ENABLE);    /* Enable ADC1 */  ADC_Cmd(ADC1, ENABLE);  /* Enable ADC1 reset calibration register */     ADC_ResetCalibration(ADC1);  /* Check the end of ADC1 reset calibration register */  while(ADC_GetResetCalibrationStatus(ADC1));  /* Start ADC1 calibration */  ADC_StartCalibration(ADC1);  /* Check the end of ADC1 calibration */  while(ADC_GetCalibrationStatus(ADC1));       /* Start ADC1 Software Conversion */   ADC_SoftwareStartConvCmd(ADC1, ENABLE);}

[ebommer]

Posted on April 09, 2014 at 22:05

I just noticed sometime unusual.  Every time I rewrite to the ADC_Config routine the position of the A/D channel 0 can change in the DMA array(not always but quite often) even if the data I write doesn't change.  From a reset A/D 0 is always mapped to DMA array [0], but if I call the routine after its been running I don't know where A/D 0 is writing its data any more.  But the data is always in order it just shifts.  Not sure if this due to some counter in the DMA not being reset.

[ebommer]

Posted on April 09, 2014 at 23:25

I think I figured it out.  I needed to disable the DMA and the A/D before re-configuring. Seems to work now.