TM4C129ENCPDT: Tigger routine for Port H

Hi,

We an encoder connected to Port H. The encoder is actually a 3 bits knob such that 2 bits are used to identify if the encoder is rotated clock wise or anti-clock wise and the 3rd Bit working as a push button to toggle between Course and Fine adjustment of power supply output current. The Knob part number is 427-121251AL121.

We are running following two interrupts;

1. Interrupt 1 on GPIO_PIN_0: Output Current setting interrupt to detect the Knob is clockwise rotated or anti-clock wise. This interrupt is working fine and there are no bouncing effect
   1. as there is a 1kRx0.1uC filter on the signal.

2. Interrupt 2 on GPIO_PIN_2: Coarse / Fine adjustment interrupt that is used to define the output current to be adjusted with a Coarse resolution or a Fine resolution. This interrupt triggers twice. There is no bouncing effect as there is a 1kRx0.1uC filter on the signal.

The Interrupt 1 works fine. It is set to trigger on Both edges of the pulse. As can be seen in the following code for Pin GPIO_PIN_0 defined as RSW_D0 pin;

void EncoderPulses_interrupt_enable(void)
{

    IntMasterDisable();
    GPIOPinTypeGPIOInput(ENC_PORT, RSW_D0);
    GPIOPinTypeGPIOInput(ENC_PORT, RSW_D1);
    GPIOPadConfigSet(ENC_PORT, RSW_D0, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);
    GPIOPadConfigSet(ENC_PORT, RSW_D1, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);  // Enable weak pullup resistor 
    GPIOIntDisable(ENC_PORT, RSW_D0);        // Disable interrupt 
    GPIOIntClear(ENC_PORT, RSW_D0);      // Clear pending interrupts
    GPIOIntRegister(ENC_PORT, Encoder_IntHandler);
    GPIOIntTypeSet(ENC_PORT, RSW_D0, GPIO_BOTH_EDGES);          
    GPIOIntEnable(ENC_PORT, RSW_D0);     // Enable interrupt
    IntMasterEnable();

}

The Interrupt 2 triggers twice each time it is activated. This interrupt is configured to trigger only on Falling edge. Following is the code for configuring the interrupt on Pin GPIO_PIN_2 defined as RSW_D2 pin.

void EncoderMode_interrupt_enable(void)
{

    IntMasterDisable();
    GPIOPinTypeGPIOInput(ENC_PORT, RSW_D2);
    GPIOPadConfigSet(ENC_PORT, RSW_D2, GPIO_STRENGTH_2MA, GPIO_PIN_TYPE_STD_WPU);  // Enable weak pullup resistor
    GPIOIntDisable(ENC_PORT, RSW_D2);        // Disable interrupt
    GPIOIntClear(ENC_PORT, RSW_D2);      // Clear pending interrupts 
    GPIOIntRegister(ENC_PORT, Encoder_IntHandler);
    GPIOIntTypeSet(ENC_PORT, RSW_D2, GPIO_FALLING_EDGE);             // Configure  falling edge trigger
    GPIOIntEnable(ENC_PORT, RSW_D2);     // Enable interrupt
    IntMasterEnable();

}

Following is the Function invoked whenever the interrupt is triggered on either of the two Pins (e.g. GPIO_PIN_2 and/or GPIO_PIN_0)

void Encoder_IntHandler(void) 
{
    SysCtlDelay(1*17000);//Clear the Interrupt after the Delay to avoid multiple Interrupt entries.
    if(GPIOIntStatus(ENC_PORT, false) & RSW_D0) //Check if the Interrupt is for RSW_D0 (GPIO_PIN_0) or RSW_D2 (GPIO_PIN_2)
    {
        uint8_t i,j;
        GPIOIntClear(ENC_PORT, RSW_D0);
        i = GPIOPinRead(ENC_PORT,RSW_D0);
        j = GPIOPinRead(ENC_PORT,RSW_D1);
        if (j==2){j = 1;} // When GPIO_PIN_1 is HIGH it GPIOPinRead() will report 0x2H. Replace it to 0x1H

        //Detect if the Encoder is moved CC or ACC 
        if(i == j){EncoderServiceReqType = EncoderCCW;} //Encoder moved Anti-Clockwise
        else{EncoderServiceReqType = EncoderCW;} //Encoder moved Clockwise


    }
    else
    {
        GPIOIntClear(ENC_PORT, RSW_D2);
        EncoderServiceReqType = EncoderMBtn;
    }

    EncoderServiceReqFlag = 1;

}

The definitions are;

#define ENC_PORT                GPIO_PORTH_BASE

#define RSW_D0                  GPIO_PIN_0 // Interrupt 1 Pin.
#define RSW_D1                  GPIO_PIN_1
#define RSW_D2                  GPIO_PIN_2 //Interrupt 2 Pin. Encoder Push Button to switch between Fine and Coarse adjustment

I thank you all for your help.

Regards,

Sahil