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GPIO general question

Question asked by Greg Hartl on May 8, 2010
Latest reply on May 10, 2010 by Greg Hartl

Hi Freescale Community,

 

I'm using the TWR-MCF51CN-KIT to develop a project and I'm having trouble with the GPIO.

 

I'm working of the built in GPIO example to get started (***\Freescale\Freescale MQX 3.5\mqx\examples\gpio). I'm able to load this project and toggel the LED with the SW2 fine. Now I'm trying to toggle a GPIO on the side expansion port of the Functional Elevator (http://cache.freescale.com/files/microcontrollers/hardware_tools/schematics/TWR-ELEV-FUNC-SCH.pdf?fpsp=1).

 

In my main task of this example, I have:

 

*****


void main_task ( uint_32 initial_data)
{


   FILE_PTR port_file_ID7;
  
GPIO_PIN_STRUCT pin_ID7[] =
  {
  ID7,
  GPIO_LIST_END
  };
   
   port_file_ID7   = fopen("gpio:write", (char_ptr) &pin_ID7 );
 
   
   while (TRUE)
   {
   ioctl(port_file_ID7, GPIO_IOCTL_WRITE_LOG0, NULL);
 
   _time_delay(1000);
  
   ioctl(port_file_ID7, GPIO_IOCTL_WRITE_LOG1, NULL);

   }


    _mqx_exit(-1);
}

 

*****

 

where I declare ID7 as:

 

#define ID7     (GPIO_PORT_TD | GPIO_PIN3)

 

in a header file (ports defined in the MCF51CN datasheet, page 5, http://cache.freescale.com/files/32bit/doc/data_sheet/MCF51CN128.pdf?fpsp=1)

 

However, when I probe this port (J9, pin/port 23 on the Functional Elevator schematic), I read no change in voltage. I tried doing this with a few other GPIOs (GPIO9, 8, 7, among others) with similar results.

 

Does anyone see anyhting overtly wrong with the code? Perhaps it's a hardware connection somewhere?

 

Any help would be appreciated.

 

Thanks,

 

-Greg

 

 

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