CCS/SW-EK-TM4C1294XL: Encoder Code development - problem with interrupts

Part Number: SW-EK-TM4C1294XL
Other Parts Discussed in Thread: EK-TM4C1294XL, TM4C1294NCPDT

Tool/software: Code Composer Studio

Dear members,

I'm trying to use an encoder with the launchpad EK-TM4C1294XL.

I've tested the Encoder using arduino, and it seems to be working properly. 1 revolution of the encoder is equal to 1024 pulses, as it should be.

My arduino code was based on this one: https://electricdiylab.com/how-to-connect-optical-rotary-encoder-with-arduino/

I am having some issues with Tiva.

The main problem is that I am not being able to read the status from the Encoder Phase B when the Encoder Phase A has generated the interruption.

I tried as well to use different interruptions and using the Phase A in one port (PD0) and the Phase B in another one (PL0), with no success.

Can someone help me?

Best regards,

Gustavo Wegher

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/gpio.h"
#include "drivers/pinout.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/rom_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "utils/uartstdio.h"

//*****************************************************************************
//
// System clock rate in Hz.
//
//*****************************************************************************
uint32_t g_ui32SysClock;

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif


//-----------------------------------------------------------------------------
// Variable Declaration for Encoder - 18.10.2020
//-----------------------------------------------------------------------------
#define ENCODER_A       GPIO_PIN_0      // PD0
#define ENCODER_B       GPIO_PIN_1      // PD1
#define delay_100ms    120000000/30

uint32_t countGen, countA, counter = 0;
uint32_t counterPartA = 0, counterPartB = 0, counterPartC = 0;
uint32_t counterPartD = 0, counterPartE = 0, counterPartF = 0;
uint32_t var_temp, encoderAStatus, encoderBStatus, varTempEncoder, varTestEncoderA, varTestEncoderB;

//-----------------------------------------------------------------------------
// Interruption Routine for Encoder - 18.10.2020
//-----------------------------------------------------------------------------
void GPIOD_ENCODER(void){

    var_temp = GPIOIntStatus(GPIO_PORTD_BASE, ENCODER_A|ENCODER_B);
    encoderAStatus = GPIOPinRead(GPIO_PORTD_BASE, ENCODER_A);
    encoderBStatus = GPIOPinRead(GPIO_PORTD_BASE, ENCODER_B);

    if (var_temp & ENCODER_A){
        if (encoderBStatus){
            counterPartA++;
        }
        else{
            counterPartB++;
        }
    }

    if (var_temp & ENCODER_B){
        if (encoderAStatus){
            counterPartC++;
        }
        else{
            counterPartD++;
        }
    }

    //
    // Print out the test results.
    //
    UARTprintf("counterPartA = %3d | counterPartB = %3d | counterPartC = %3d | counterPartD = %3d\r", counterPartA, counterPartB, counterPartC, counterPartD);

    //SysCtlDelay(delay_100ms);

    GPIOIntClear(GPIO_PORTD_BASE, ENCODER_A|ENCODER_B);

}

//*****************************************************************************
//
// Configure the UART and its pins.  This must be called before UARTprintf().
//
//*****************************************************************************
void
ConfigureUART(void)
{
    //
    // Enable the GPIO Peripheral used by the UART.
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

    //
    // Enable UART0
    //
    ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

    //
    // Configure GPIO Pins for UART mode.
    //
    ROM_GPIOPinConfigure(GPIO_PA0_U0RX);
    ROM_GPIOPinConfigure(GPIO_PA1_U0TX);
    ROM_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);

    //
    // Initialize the UART for console I/O.
    //
    UARTStdioConfig(0, 115200, g_ui32SysClock);
}

//*****************************************************************************
//
// Print "Hello World!" to the UART on the Intelligent UART Module.
//
//*****************************************************************************
int
main(void)
{
    //
    // Run from the PLL at 120 MHz.
    //
    g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                SYSCTL_OSC_MAIN | SYSCTL_USE_PLL |
                SYSCTL_CFG_VCO_480), 120000000);

    //
    // Configure the device pins.
    //
    PinoutSet(false, false);

    //
    // Enable the GPIO pins for the LED D1 (PN1).
    //
    ROM_GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, GPIO_PIN_1);


    //
    // Enable the GPIOD Peripherals
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOD)) {}

    //
    // Configure the GPIOD as Inputs
    //
    GPIOPinTypeGPIOInput(GPIO_PORTD_BASE, ENCODER_A|ENCODER_B);
    GPIOPadConfigSet    (GPIO_PORTD_BASE, ENCODER_A|ENCODER_B, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);
    GPIOIntTypeSet      (GPIO_PORTD_BASE, ENCODER_A|ENCODER_B, GPIO_RISING_EDGE);
    GPIOIntRegister     (GPIO_PORTD_BASE, GPIOD_ENCODER);
    GPIOIntEnable       (GPIO_PORTD_BASE, ENCODER_A|ENCODER_B);

    //
    // Initialize the UART.
    //
    ConfigureUART();

    //
    // Hello!
    //
    UARTprintf("Hello, world!\n");

    while(1){}
}