accelerometer.c

ucos-ii 的完整代码

/*
*********************************************************************************************************
*                                               uC/OS-II
*                                         The Real-Time Kernel
*
*                                (c) Copyright 2004, Micrium, Weston, FL
*                                          All Rights Reserved
*
*
*                                      BOARD SUPPORT PACKAGE (BSP)
*                                         Frescale MCF51QE
*
* File : accelerometer.c
* By   : Eric Shufro
*********************************************************************************************************
*/

#include <includes.h>

/*
*********************************************************************************************************
*                                       CONSTANTS
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*                                       PROTOTYPES
*********************************************************************************************************
*/

/*
*********************************************************************************************************
*                                       Accelerometer_Init()()
*
* Description: This function initializes the on-chip ATC peripheral for use with the
*              on-board tri-axis accelerometer.
*
* Arguments  : None.
*
* Returns    : None.
*
* Note(s)    : None.
*********************************************************************************************************
*/

void  Accelerometer_Init (void) 
{
    SCGC1  |=   SCGC1_ADC_MASK;                                         /* Ensure ADC clock is enabled                              */
    ADCCFG  =   ADCCFG_MODE0_MASK | ADCCFG_ADIV0_MASK;                  /* Input clock divide by 2, 12 bit conversions              */
}

/*
*********************************************************************************************************
*                                       Accerlometer_Rd()
*
* Description: This function reads the ATC value for the specified channel
*
* Arguments  : channel  The ATC channel to read. One of the following channels 
*                       should be specified:
*                           ATC_RD_X
*                           ATC_RD_Y
*                           ATC_RD_Z
*
* Returns    : The RAW ATC channel value for the selected channel. 0 when channel is invalid.
*
* Note(s)    : None.
*********************************************************************************************************
*/

CPU_INT16U  Accelerometer_Rd (CPU_INT08U channel) 
{
    CPU_INT08U  timeout;
    
   
    timeout         = 100;                                              /* Configure a timeout value to prevent an infinite loop    */
           
    switch (channel) {                                                  /* Select the specified ATC channel to read                 */
        case ATC_RD_X:
             ADCSC1 = ATC_RD_X;
             break;

        case ATC_RD_Y:
             ADCSC1 = ATC_RD_Y;
             break;

        case ATC_RD_Z:
             ADCSC1 = ATC_RD_Z;
             break;
             
        default:
             return (0);                                                /* Invalid channel argument, return 0                       */
             break;
    }
        
    while (((ADCSC1 & ADCSC1_COCO) == 0) && (timeout > 0)) {            /* Wait until conversion is complete                        */
        timeout--;
    }

    return (ADCR);
}