GPIO o/P

Hi,

did you initialize the gpio registers correctly (mux, dir)?

Best regards,
Edwin Krasser

Hi,

S. I did.

void Gpio_select(void)
{
    EALLOW;
    GpioCtrlRegs.GPAMUX1.all = 0;        // GPIO15 ... GPIO0 = General Puropse I/O
    GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1;    // ePWM1A active

    GpioCtrlRegs.GPAMUX2.all = 0;        // GPIO31 ... GPIO16 = General Purpose I/O
    GpioCtrlRegs.GPBMUX1.all = 0;        // GPIO47 ... GPIO32 = General Purpose I/O
    GpioCtrlRegs.GPBMUX2.all = 0;        // GPIO63 ... GPIO48 = General Purpose I/O
    GpioCtrlRegs.GPCMUX1.all = 0;        // GPIO79 ... GPIO64 = General Purpose I/O
    GpioCtrlRegs.GPCMUX2.all = 0;        // GPIO87 ... GPIO80 = General Purpose I/O
     
    GpioCtrlRegs.GPADIR.all = 0;
    GpioCtrlRegs.GPADIR.bit.GPIO9 = 1;    // peripheral explorer: LED LD1 at GPIO9
    GpioCtrlRegs.GPADIR.bit.GPIO11 = 1;    // peripheral explorer: LED LD2 at GPIO11

    GpioCtrlRegs.GPBDIR.all = 0;        // GPIO63-32 as inputs
    GpioCtrlRegs.GPBDIR.bit.GPIO34 = 1;    // peripheral explorer: LED LD3 at GPIO34
    GpioCtrlRegs.GPBDIR.bit.GPIO49 = 1; // peripheral explorer: LED LD4 at GPIO49
    GpioCtrlRegs.GPBDIR.bit.GPIO60 = 1; //
    GpioCtrlRegs.GPBDIR.bit.GPIO61 = 1; //
    GpioCtrlRegs.GPCDIR.all = 0;        // GPIO87-64 as inputs
    EDIS;
} 

Hi,

the initializations look good (If you check the initializations using the jtag interface, do you read the correct values?).

And after executing

GpioDataRegs.GPASET.bit.GPIO9=1;

the output pin does not output high. Do I understand it correctly?
And one more question: Which c2000 do you use?

Best regards,
Edwin Krasser

Sir,

Wat do u mean by 'If you check the initializations using the jtag interface, do you read the correct values?'

I am using USB100V2 interface only.

The o/p pin is going HIGH but it is at 0.3 volts only. When it is not HIGH ( i.e LOW) , it is showing 0 V.

wat may be the problem?

Hi,

did you check the pins? Do you have a short circuit (or a very low resistance connection) to ground? And what's the circuit connected to the pin?

Best regards,
Edwin Krasser

am using TI explorer kit only. It is provided with two GPIO ports 60,61. I have made it HIGH when the code meets the required condition.

I connected a CRO probe to GPIO60 and observing. It is absolutely at zero when the condition fails but when it satisfies condition, it is going to 3 volt level.

If it has short ciruit problem, then it will not show two stable states na. Correct me if i wrong.

Hi,

excuse me, but I do not understand it any more. Is it 300 mV or 3 V? Did you check it with a multimeter? Or do you just use your scope (Does CRO mean Cathode Ray Oscilloscope?)? What about your probe (x1, x10)?

Best regards,
Edwin Krasser

s..am getting 3 V. problm is solved.

thanks for the reply..thanks a lot.

Now i wud like to drive a relay using this pin. How can it b possibl? suggest me.

thanks in advance,

Hi,

I do not know which relay you want to use. But especially the low voltage relays will need some current (significant more than 4 mA). So you will need a low side switch (guaranteed on with 3.3 V gate voltage) which is switching the relay. And do not forget a small diode reverse direction, parallel to the relay to avoid overvoltages when switching off. And you can add a 3.3 kOhm pull down resistor to the gpio because the internal pull up would cause the MOST (and the relay) to turn on when resetting.

Best regards,
Edwin Krasser

            V++       V++
             |         |
           -----       C
            / \ diode  O
            ---        I
             |         L...of relay
             o----------
           |--
GPIO ------|
       |   |--
      PD     |
       |    GND
      GND

Hi, thank u for ur suggestion sir.. I wil try and will give feedback soon. Hav a nice day