rt-thread-official/bsp/efm32/dev_misc.c

/***************************************************************************//**
 * @file 	dev_misc.c
 * @brief 	Miscellaneous drivers of RT-Thread RTOS for EFM32
 * 	COPYRIGHT (C) 2011, RT-Thread Development Team
 * @author 	onelife
 * @version 0.4 beta
 *******************************************************************************
 * @section License
 * The license and distribution terms for this file may be found in the file 
 * LICENSE in this distribution or at http://www.rt-thread.org/license/LICENSE
 *******************************************************************************
 * @section Change Logs
 * Date			Author		Notes
 * 2011-02-22	onelife		Initial creation for EFM32
 * 2011-07-27	onelife		Modify according to ADC driver changes
 ******************************************************************************/

/***************************************************************************//**
 * @addtogroup efm32
 * @{
 ******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "board.h"
#include "drv_adc.h"

#if defined(RT_USING_MISC)
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
#ifdef RT_MISC_DEBUG
#define misc_debug(format,args...) 			rt_kprintf(format, ##args)
#else
#define misc_debug(format,args...)
#endif

/* Private constants ---------------------------------------------------------*/
static rt_device_t 					adc0;
static struct efm32_adc_control_t 	control = \
	{ADC_MODE_SINGLE, {}, {0, (rt_uint8_t)EFM32_NO_DMA}};

/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
rt_int32_t efm32_misc_getCelsius(rt_uint32_t adcSample);

/* Private functions ---------------------------------------------------------*/
/***************************************************************************//**
 * @brief
 *   Get current temperature value in degree celsius
 *
 * @details
 *
 * @note
 *
 * @return
 *   Temperature value (signed integer) in degree celsius times 100
 *
 ******************************************************************************/
rt_int32_t rt_hw_get_temp(void)
{
	ADC_InitSingle_TypeDef 		singleInit = ADC_INITSINGLE_DEFAULT;
	struct efm32_adc_result_t 	result;
	rt_uint32_t 				temp;

	/* Set input to temperature sensor. Acquisition time must be 256 cycles. 
	   Reference must be 1.25V */
	singleInit.acqTime 		= adcAcqTime32;
	singleInit.reference 	= adcRef1V25;
	singleInit.input 		= adcSingleInpTemp;

	control.single.init 	= &singleInit;
	adc0->control(adc0, RT_DEVICE_CTRL_ADC_MODE, &control);
	result.mode 			= control.mode;
	result.buffer 			= (void *)&temp;
	adc0->control(adc0, RT_DEVICE_CTRL_RESUME, &result);
	adc0->control(adc0, RT_DEVICE_CTRL_ADC_RESULT, &result);

	return efm32_misc_getCelsius(temp);
}

/***************************************************************************//**
 * @brief
 *   Get current VDD value in volt
 *
 * @details
 *
 * @note
 *
 * @return
 *   VDD value (unsigned integer) in volt times 100
 *
 ******************************************************************************/
rt_uint32_t rt_hw_get_vdd(void)
{
	ADC_InitSingle_TypeDef 		singleInit = ADC_INITSINGLE_DEFAULT;
	struct efm32_adc_result_t 	result;
	rt_uint32_t 				vdd;

	/* Set input to temperature sensor. Reference must be 1.25V */
	singleInit.acqTime 		= adcAcqTime32;
	singleInit.reference 	= adcRef1V25;
	singleInit.input 		= adcSingleInpVDDDiv3;

	control.single.init 	= &singleInit;
	adc0->control(adc0, RT_DEVICE_CTRL_ADC_MODE, &control);
	result.mode 			= control.mode;
	result.buffer 			= (void *)&vdd;
	adc0->control(adc0, RT_DEVICE_CTRL_RESUME, &result);
	adc0->control(adc0, RT_DEVICE_CTRL_ADC_RESULT, &result);

	return (vdd * 125 * 3) / 4096;
}

/***************************************************************************//**
 * @brief
 *   Initialize all the miscellaneous drivers
 *
 * @details
 *
 * @note
 *
 * @return
 *	 Error code
 ******************************************************************************/
rt_err_t rt_hw_misc_init(void)
{
	do
	{
		/* Find ADC device */
		adc0 = rt_device_find(RT_ADC0_NAME);
		if (adc0 == RT_NULL)
		{
			misc_debug("Misc err: Can't find device: %s!\n", RT_ADC0_NAME);
			break;
		}
		misc_debug("Misc: Find device %s\n", RT_ADC0_NAME);
		
		return RT_EOK;
	} while (0);

	misc_debug("Misc err: Init failed!\n");
	return -RT_ERROR;
}

/***************************************************************************//**
 * @brief 
 *   Convert ADC result to degree celsius.
 *
 * @details
 *
 * @note 
 *   See section 2.3.4 in the reference manual for details on this calculatoin
 *
 * @param adcResult 
 *   Raw value from ADC to be converted to celsius
 *
 * @return 
 *   The temperature value (signed integer) in degrees celsius times 100
 *
 ******************************************************************************/
rt_int32_t efm32_misc_getCelsius(rt_uint32_t adcResult)
{
	/* Factory calibration temperature from device information page. */
	rt_int32_t cal_temp 	= ((DEVINFO->CAL & _DEVINFO_CAL_TEMP_MASK) \
								>> _DEVINFO_CAL_TEMP_SHIFT) * 100;

	/* Factory calibration value from device information page. */
	rt_int32_t cal_value	= ((DEVINFO->ADC0CAL2 & _DEVINFO_ADC0CAL2_TEMP1V25_MASK) \
								>> _DEVINFO_ADC0CAL2_TEMP1V25_SHIFT) * 10000;

	/* Temperature gradient (from datasheet) in (ADC unit / degree celsius * 100) */
	rt_int32_t t_grad 		= -385;

	return (cal_temp - (cal_value - (rt_int32_t)adcResult * 10000) / t_grad);
}

/*******************************************************************************
 * 	Export to FINSH
 ******************************************************************************/
#ifdef RT_USING_FINSH
#include <finsh.h>

void list_temp(void)
{
	rt_int32_t temp = rt_hw_get_temp();

	rt_kprintf("Temperature is %2d.%02d C\n", temp / 100, temp % 100);
}
FINSH_FUNCTION_EXPORT(list_temp, list current temperature value.)

void list_vdd(void)
{
	rt_uint32_t vdd = rt_hw_get_vdd();
	
	rt_kprintf("VDD is %1d.%02d V\n", vdd / 100, vdd % 100);
}
FINSH_FUNCTION_EXPORT(list_vdd, list current VDD value.)

#endif /* RT_USING_FINSH */

#endif /* defined(RT_USING_MISC) */
/***************************************************************************//**
 * @}
 ******************************************************************************/