////  $Id: sensors.c 348 2009-01-12 01:24:28Z jcw $//  $Revision: 348 $//  $Author: jcw $//  $Date: 2009-01-11 20:24:28 -0500 (Sun, 11 Jan 2009) $//  $HeadURL: http://tinymicros.com/svn_public/arm/lpc2148_demo/trunk/sensors/sensors.c $//#include <stdio.h>#include <string.h>#include <unistd.h>#include <fcntl.h>#include "FreeRTOS.h"#include "task.h"#include "semphr.h"#include "../main.h"#include "../adc/adc.h"#include "../dac/dac.h"#include "../leds/leds.h"#include "sensors.h"////  If CFG_SENSORS is not defined, we still compile the code, it's just not//  included.  Define TASKHANDLE_SENSORS so we compile.  Normally this is//  defined in main.h, but it's #ifndef'ed out so that we don't allocate a task//  handle slot for it when sensors support isn't included.//#ifndef CFG_SENSORS#define TASKHANDLE_SENSORS 0#endif//////static sensorData_t sensorData;static xSemaphoreHandle semaphore = NULL;////  Return 1 if got a copy, 0 if not.//int sensorsCopyData (sensorData_t *dst){  if (semaphore && (xSemaphoreTake (semaphore, 100 / portTICK_RATE_MS) == pdTRUE))  {    memcpy (dst, &sensorData, sizeof (sensorData));    xSemaphoreGive (semaphore);    return 1;  }  memset (dst, 0, sizeof (sensorData_t));  return 0;}//////static portTASK_FUNCTION (vSensorsTask, pvParameters __attribute__ ((unused))){  portTickType xTickCount;  int adcValueRaw;  int adcValue;  int adcLastValue = -1;  int adcChanged = -1;  int dacValue = 0;  int dacDirection = -16;  memset (&sensorData, 0, sizeof (sensorData));  if (!semaphore)    vSemaphoreCreateBinary (semaphore);  xTickCount = xTaskGetTickCount ();  for (;;)  {    vTaskDelayUntil (&xTickCount, 100 / portTICK_RATE_MS);    //    //  Adjust the DAC value so we output a slow sine wave    //    if ((dacValue <= 0) || (dacValue >= (1024 - dacDirection)))      dacDirection = 0 - dacDirection;    dacSet (dacValue);    dacValue += dacDirection;    //    //  Read the current ADC value, keep only top 2 bits.  If it changes,    //  tell the LED task to change the blink rate.    //    if ((adcValue = ((adcValueRaw = adcRead0_3 ()) >> 8)) != adcLastValue)    {      ledsSetDutyCycle (adcValue);      adcLastValue = adcValue;      adcChanged++;    }    //    //  Update the sensors data    //    if (xSemaphoreTake (semaphore, portMAX_DELAY) == pdTRUE)    {      sensorData.sensorCount++;      sensorData.adcChanges = adcChanged;      sensorData.adcValue = adcValue;      sensorData.adcValueRaw = adcValueRaw;      sensorData.dacValue = dacValue;      sensorData.dacDirection = dacDirection;      xSemaphoreGive (semaphore);    }  }}//////signed portBASE_TYPE sensorsTaskStart (void){  return xTaskCreate (vSensorsTask,  (const signed portCHAR * const) "Sensors", configMINIMAL_STACK_SIZE, NULL, (tskIDLE_PRIORITY + 2), &taskHandles [TASKHANDLE_SENSORS]);}signed portBASE_TYPE sensorsTaskStop (void){  if (!taskHandles [TASKHANDLE_SENSORS])    return 0;    vTaskDelete (taskHandles [TASKHANDLE_SENSORS]);  taskHandles [TASKHANDLE_SENSORS] = NULL;  return 1;}