ADC sampling

Hello Jia,

When you go to Console of CCS what does the error show up as. Edit -> Console

Regards
Amit

Hi Amit,

Really appreciate your help.

Below has shown in the console of CCS:


undefined first referenced
symbol in file
--------- ----------------

>> Compilation failure
ADCHardwareOversampleConfigure ./main.obj
ADCIntClear ./main.obj
ADCIntStatus ./main.obj
ADCProcessorTrigger ./main.obj
ADCSequenceConfigure ./main.obj
ADCSequenceDataGet ./main.obj
ADCSequenceEnable ./main.obj
ADCSequenceStepConfigure ./main.obj
SysCtlClockSet ./main.obj
SysCtlDelay ./main.obj
SysCtlPeripheralEnable ./main.obj

error #10234-D: unresolved symbols remain
error #10010: errors encountered during linking; "ADC.out" not built
gmake: *** [ADC.out] Error 1
gmake: Target `all' not remade because of errors.

**** Build Finished ****

Hello Jia

The driver lib.lib pre compiled library is missing in the linker stage

You would need to add the same from the to aware installation.

Regards

Amit

Hi Amit,

Thanks for your help. The error has been solved. There is no result when i was collecting an input signal from the pressure transducer. Anyone can help?

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/sysctl.h"
#include "driverlib/adc.h"
#include "driverlib/gpio.h"
#include "driverlib/timer.h"
#include "driverlib/interrupt.h"

int main(void)
{
uint32_t ui32ADC0Value[4];

volatile uint32_t ui32PressureAvg;

SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);

SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0); //Enable ADC0 Peripheral

ADCSequenceEnable(ADC0_BASE,0);

GPIOPinTypeADC(GPIO_PORTE_BASE,GPIO_PIN_3);

ADCHardwareOversampleConfigure(ADC0_BASE, 64);

ADCSequenceConfigure(ADC0_BASE, 0, ADC_TRIGGER_PROCESSOR, 0);

ADCSequenceStepConfigure(ADC0_BASE,0,0,ADC_CTL_CH0);
ADCSequenceStepConfigure(ADC0_BASE,0,1,ADC_CTL_CH0);
ADCSequenceStepConfigure(ADC0_BASE,0,2,ADC_CTL_CH0);
ADCSequenceStepConfigure(ADC0_BASE,0,3,ADC_CTL_CH0|ADC_CTL_IE | ADC_CTL_END);

ADCSequenceEnable(ADC0_BASE, 0);

while(1)
{

ADCIntClear(ADC0_BASE,0);//Clear ADC interrupt
ADCProcessorTrigger(ADC0_BASE,0); //Trigger ADC interrupt

while(!ADCIntStatus(ADC0_BASE, 0, false))
{
}

ADCSequenceDataGet(ADC0_BASE,0,ui32ADC0Value);

GPIOPinTypeGPIOOutput(GPIO_PORTE_BASE,GPIO_PIN_2);

SysCtlDelay(2000000);

}

}

Hello Jia,

There are multiple things to consider

1. Is the code executing? I doubt... Why because Port E is not enabled when you configure the GPIO for ADC function. Has to be in a Bus Fault Handler.

2. What is the analog output from the transducer. Is it measurable by a multimeter and in the range of conversion of ADC and step size of the ADC per LSB. Please note that there is a delta error for the ADC.

What you should try is to connect fixed voltage signals like 1.2V, 1.8V, etc till 3.3V to see if the conversion is happening to test the TM4C code.

Regards
Amit

Hi Amit,

I'm so sorry to keep bothering you. :( As i'm a newie to TIVA.

Pertaining to your questions:
1. May i know what is Bus Fault Handler??

2. It's a Millivolt analog output. Yes is measurable by multimeter and in the range of conversion of ADC and step size of the ADC per LSB. Sorry, what is delta error for ADC?

We used a fixed voltage signals of 3.3V to convert the signal.

Thanks and sorry.....

Hello Jia,

I saw from the question that indeed you are a newbie. But the questions are the right questions you ask. So here are the answers

1. The bus fault handler, is to handle any unexpected issue that the CPU code execution may encounter. In this case since the peripheral is not enabled, the read or write to it will not yield the correct data. Hence a Bus Fault is raised so that program execution is aborted and the CPU goes to the bus fault handler to indicate of terminated program execution

2. The delta error is the number of LSB's of ADC conversion which would be seen when the voltage is held constant and a conversion is done over and over again.

Regards
Amit