Question to GPIO

lpcware — Thu, 16 Jun 2016 02:47:05 GMT

Content originally posted in LPCWare by ledi007 on Wed Jan 27 04:47:42 MST 2016
Hello,

im new in programming an arm-controller and using lpcxpresso with the lpcxpresso board lpc1114.
So, i use the example project "cmsis2_blinky" and want to control a LED on PORT0, Bit10.

First, i set the direction register and in the while-loop the portin every half a second to high or low.
The result is, that the LED on PORT0 Bit10 is toggeling with an high frequency.

Can you explain, why this is?

here my code:

//*****************************************************************************
//   +--+
//   | ++----+
//   +-++    |
//     |     |
//   +-+--+  |
//   | +--+--+
//   +----+    Copyright (c) 2010-11 Code Red Technologies Ltd.
//
// LED flashing Timer16 application for LPCXPresso1114 board
//
// Software License Agreement
//
// The software is owned by Code Red Technologies and/or its suppliers, and is
// protected under applicable copyright laws.  All rights are reserved.  Any
// use in violation of the foregoing restrictions may subject the user to criminal
// sanctions under applicable laws, as well as to civil liability for the breach
// of the terms and conditions of this license.
//
// THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// USE OF THIS SOFTWARE FOR COMMERCIAL DEVELOPMENT AND/OR EDUCATION IS SUBJECT
// TO A CURRENT END USER LICENSE AGREEMENT (COMMERCIAL OR EDUCATIONAL) WITH
// CODE RED TECHNOLOGIES LTD.
//
//*****************************************************************************


#include "LPC11xx.h"                        /* LPC11xx definitions */
#include "timer16.h"
#include "clkconfig.h"
#include "gpio.h"

#include <cr_section_macros.h>
#include <NXP/crp.h>

// Variable to store CRP value in. Will be placed automatically
// by the linker when "Enable Code Read Protect" selected.
// See crp.h header for more information
__CRP const unsigned int CRP_WORD = CRP_NO_CRP ;

// LPCXpresso processor card LED
#define LED_PORT 0// Port for led
#define LED_BIT 7// Bit on port for led
#define LED_ON 1// Level to set port to turn on led
#define LED_OFF 0// Level to set port to turn off led

extern volatile uint32_t timer16_0_counter;

int main (void)
{
  GPIOInit();

  // Initialise Timer16_0 to tick at rate of 1/2000th of second.
// Note that as this is a 16 bit timer, the maximum count we can
// load into timer is 0xFFFF, or 65535. Default clock speed
// set up by CMSIS SystemInit function - SystemCoreClock - is
// 48MHz or 48000000 Hz. Dividing this by 2000 is 24000 which is
// within appropriate timer16 maximum. This could be extended
// if timer routine extended to make use of Prescale Counter register
// Note by default LPC_SYSCON->SYSAHBCLKDIV is 1.
  init_timer16(0, (SystemCoreClock/LPC_SYSCON->SYSAHBCLKDIV)/2000 );

  // Initialise counter that counts Timer16_0 ticks
  timer16_0_counter = 0;

  //Enable Timer16_0
  enable_timer16(0);

  // Set port for LED to output
  GPIOSetDir( LED_PORT, LED_BIT, 1 );
  GPIOSetDir( 0, 10, 1 );// Set PORT0 direction Bit10 to output

  while (1)                                /* Loop forever */
  {

// LED is on for 1st half-second
if ( (timer16_0_counter > 0) && (timer16_0_counter <= 1000) )
{
GPIOSetValue( LED_PORT, LED_BIT, LED_OFF );
GPIOSetValue(0,10,1);// PORT0 Bit10 High
}

// LED is off for 2nd half-second
if ( (timer16_0_counter > 1000) && (timer16_0_counter <= 2000) )
{
GPIOSetValue( LED_PORT, LED_BIT, LED_ON );
GPIOSetValue(0,10,0);// PORT0 Bit10 Low
}

// Reset counter
else if ( timer16_0_counter > 2000 )
{
timer16_0_counter = 0;
}
  }
}

Re: Question to GPIO

lpcware — Thu, 16 Jun 2016 02:47:06 GMT

Content originally posted in LPCWare by ledi007 on Wed Jan 27 05:04:22 MST 2016
!!!! I solved the problem already!!!! :)

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