CCS/TM4C123GH6PM: Analog Value related Problem

anurag sohane

Part Number: TM4C123GH6PM

Tool/software: Code Composer Studio

Hello Sir,

I have use PE-3 pin for analog pin with 3.3 V input on this port. The analog value should be come 4095 according to 12 bit ADC. But that is not comming in attached file.

Fullscreen ADC new.txt Download

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/tm4c123gh6pm.h"
#include "driverlib/sysctl.h"
#include "driverlib/adc.h"
#include "driverlib/gpio.h"
#include "driverlib/uart.h"
#include "driverlib/pin_map.h"
volatile long adcResult=0;
int a,b,c,d,e,f;

void GPIO_InIt(void)
{
    GPIO_PORTE_DIR_R &= ~0x10;              // Make PE1 input
    GPIO_PORTE_AFSEL_R |=0x10;              // Set PE as alternate fun.
    GPIO_PORTE_DEN_R &=~0x10;           // Disable Digital Enable on PE3
    GPIO_PORTE_AMSEL_R |=0x10;              // Enable Analog functionality on PE3

    ADC0_ACTSS_R &=~0x0008; // Disable sample Sequencer 3(SS3)
    ADC0_EMUX_R &=~0xF; // Software Trigger Conversion                 // Configure Trigger event : continuous mode
    ADC0_SSMUX3_R |=0; //  Get input from channel 0
    ADC0_SSCTL3_R |=0x0006; // Take one sample at a time set flat at 1st sample
    ADC0_ACTSS_R |=0x0008; //  Enable SS3
}

void ADC0Seq3_Handler(void)
{
    ADC0_PSSI_R|=0x0008; //  Start Conversion at SS3
    while((ADC0_RIS_R &  0x08)==0){} // Wait for conversion complete
    adcResult = ADC0_SSFIFO3_R & 0xFFF;
    ADC0_ISC_R = 0x0008;
}

int main(void)
{
    SYSCTL_RCGCGPIO_R |=0x10; // Enable clock for Port E
    SYSCTL_RCGCADC_R |=0x01; // Enable Clock for ADC Module 0

    GPIO_InIt();

    while(1)
    {
       ADC0Seq3_Handler();

    }
}

Fullscreen ADC new.txt Download

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/tm4c123gh6pm.h"
#include "driverlib/sysctl.h"
#include "driverlib/adc.h"
#include "driverlib/gpio.h"
#include "driverlib/uart.h"
#include "driverlib/pin_map.h"
volatile long adcResult=0;
int a,b,c,d,e,f;

void GPIO_InIt(void)
{
    GPIO_PORTE_DIR_R &= ~0x10;              // Make PE1 input
    GPIO_PORTE_AFSEL_R |=0x10;              // Set PE as alternate fun.
    GPIO_PORTE_DEN_R &=~0x10;           // Disable Digital Enable on PE3
    GPIO_PORTE_AMSEL_R |=0x10;              // Enable Analog functionality on PE3

    ADC0_ACTSS_R &=~0x0008; // Disable sample Sequencer 3(SS3)
    ADC0_EMUX_R &=~0xF; // Software Trigger Conversion                 // Configure Trigger event : continuous mode
    ADC0_SSMUX3_R |=0; //  Get input from channel 0
    ADC0_SSCTL3_R |=0x0006; // Take one sample at a time set flat at 1st sample
    ADC0_ACTSS_R |=0x0008; //  Enable SS3
}

void ADC0Seq3_Handler(void)
{
    ADC0_PSSI_R|=0x0008; //  Start Conversion at SS3
    while((ADC0_RIS_R &  0x08)==0){} // Wait for conversion complete
    adcResult = ADC0_SSFIFO3_R & 0xFFF;
    ADC0_ISC_R = 0x0008;
}

int main(void)
{
    SYSCTL_RCGCGPIO_R |=0x10; // Enable clock for Port E
    SYSCTL_RCGCADC_R |=0x01; // Enable Clock for ADC Module 0

    GPIO_InIt();

    while(1)
    {
       ADC0Seq3_Handler();

    }
}

over 5 years ago

0 anurag sohane over 5 years ago

Intellectual 310 points

Sir, Here i am enable PE4 port with 3.3 V input. But PE3 port showing same value as PE4. Please suggest me answer.

0 Bob Crosby over 5 years ago

TI__Guru 72500 points

As mentioned in response to your other post, we strongly discourage the use of direct register writes and encourage the use of the TivaWare library functions. This will simplify your code, reduce the number of errors and allow others to assist you. Here is an example of reading two ADC values one after the other (1uS) using the TivaWare functions.

#include <stdint.h>
#include <stdbool.h>
#include <inc/hw_memmap.h>
#include "driverlib/gpio.h"
#include "driverlib/adc.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"


int main(void)
{
    unsigned int array[4];

    //Set clock to 16 MHz
    SysCtlClockSet(SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);

    // Enable the GPIOE peripheral

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);

    // Enable the ADC0 module.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);

    // Wait for the GPIOE module to be ready.

    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE))
    {
    }
    // Wait for the ADC0 module to be ready.
    //
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_ADC0))
    {
    }

    //Configures ADC pins PE3 (AIN0) and PE2 (AIN1)
    GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_3 | GPIO_PIN_2);

    //Configure ADC functions
    // Using Sequence 1 which has a 4 entry FIFO
    ADCSequenceConfigure(ADC0_BASE, 1, ADC_TRIGGER_PROCESSOR, 0);
    ADCSequenceStepConfigure(ADC0_BASE, 1, 0, ADC_CTL_CH0 );
    ADCSequenceStepConfigure(ADC0_BASE, 1, 1, ADC_CTL_CH1 | ADC_CTL_IE | ADC_CTL_END);
    ADCSequenceEnable(ADC0_BASE,1);
    ADCIntClear(ADC0_BASE, 1);
    ADCClockConfigSet(ADC0_BASE, ADC_CLOCK_SRC_PIOSC | ADC_CLOCK_RATE_FULL, 1);



    while(1)
    {
        ADCProcessorTrigger(ADC0_BASE, 1);
        //wait for the conversion to be completed
        while(!ADCIntStatus(ADC0_BASE, 1, false))
        {
        }
        //clear Interrupt flag
        ADCIntClear(ADC0_BASE, 1);

        //Read ADC input and store PE3 in array[0], PE2 in array[1]
        ADCSequenceDataGet(ADC0_BASE, 1, array); //read the analog values
    }
}

0 anurag sohane over 5 years ago in reply to Bob Crosby

Intellectual 310 points

Thanks sir,

I have again two more question regarding sample/ sec and UART. First, please tell me API regarding analog data in samples/second. Second How to send this multiple anlog data on UART toghter.

0 Bob Crosby over 5 years ago in reply to anurag sohane

TI__Guru 72500 points

The example above uses a software trigger and one ADC converter to take two different samples. The ADC clock is 16MHz and each conversion takes 16 clocks. If you were to do continuous conversions instead of software trigger that, each conversion takes 1uS. Your sample rate would be 500K samples/S for each of the two channels.

You are not likely to be able to send 1 million 12-bit conversions out a UART every second. What sample rate do you need? If not sure, what will you do with the data after it goes out the UART?

0 anurag sohane over 5 years ago in reply to Bob Crosby

Intellectual 310 points

Sir,

I want to acquire 4 muscle EMG data at 2048 sample/sec. So i want to know, How could i record these muscle data at these sample rate.

0 Bob Crosby over 5 years ago in reply to anurag sohane

TI__Guru 72500 points

OK, if you want to send 4 12-bit values 2048 times every second, you need to transfer 2 bytes for each value (12 bits plus an identifier as to which sample it is). Each byte is 10 bits (start bit, 8 data bits and a stop bit). That means a baud rate of at least 163,840 bits/second. The next fastest standard baud rate is 230,400 baud. Of course the application receiving the data needs to know how to interpret these binary values.

You can use a timer to trigger the ADC conversions every 488.275uS. (It is actually slightly faster than 2048 times/second.)

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CCS/TM4C123GH6PM: Analog Value related Problem