STM32 AM2305 High precision temperature and humidity sensor driver

Recently used temperature and humidity sensor, AM2305 drive, single bus, after power on at least a delay of 2S to read temperature and humidity, temperature accuracy is high, with the same as DS18B20, data with calibration, will not appear ds18b20, and timing requirements are not high

/*************************************************************************************************************
 * File name: am2305.c * Function: STM32 AM2305 high precision temperature and humidity sensor driver * Author: cp1300@139.com * created on: 2014-09-20 * Last modified: 2014-09-20 * Detailed : Requires delay function support * Note that the delay accuracy is as high as possible * do not be interrupted long time when reading, because 1wire is strict in time requirements ************************************************** /#include "system.h" #include "delay.h" #include "					AM2305.h "//ds18b20 uses GPIOE0 #define AM2305_CLK_INIT () deviceclockenable (Am2305_dev, ENABLE);	Clock enable #define AM2305_IO_OUT () gpiox_init (am2305_gpiox,am2305_bitx,out_pp,speed_10m);			Set AM2305 IO as output, #define AM2305_IO_IN () gpiox_init (am2305_gpiox,am2305_bitx,in_ipu,0); Set AM2305 io as the pull-up input, #define AM2305_DQ_IN () ((am2305_in)? 1:0)//Read AM2305 IO #define AM2305_DQ_OUT (x) (am2305_o			UT = x)//write AM2305 IO #define Am2305_iodown () gpiox_init (am2305_gpiox,am2305_bitx,in_ipt,0); Power-down, drop-down input//exact US delay #define Am2305_delay_us (x) delay_us (x)//am2305 power-down void Am2305_powerdown (void) {Am2305_iodown ();} /************************************************************************************************************** * Function: void Am2305_reset (void) * Function: AM2305 reset * Parameter: None * return: No * dependency: underlying macro definition * AS By: Cp1300@139.com * Time: 2014-09-20 * Last modified: 2014-09-20 * Description: No ************************************                 
	/void Am2305_reset (void) { 			Am2305_io_out (); 			SET OUTPUT am2305_dq_out (0);    	Pull Low DQ am2305_delay_us (1000); 			Pull down at least 800uS am2305_dq_out (1);	 	Dq=1 Am2305_delay_us (30); Host pull High 20~40us}/***********************************************************************************************        	* Function: bool Am2305_check (void) * function: Wait for AM2305 response * parameter: None * return : FALSE: Detection failure; 
TRUE: Detection succeeded * Dependency: underlying macro definition * Author: cp1300@139.com * Time: 2014-09-20 * Last modified: 2014-09-20 * Description: Detect the presence of AM2305 ***************************************************************************************************************
	
	/bool Am2305_check (void) {u32 retry=0;
		Am2305_io_in ();//set INPUT while (am2305_dq_in () &&retry<100)//am2305 pulls down 75~85us {retry++;
	Am2305_delay_us (1);
		} if (retry>=100) {uart_printf ("am2305:retry1:%d\r\n", retry);
	return FALSE;
    } retry=0; while (!
		Am2305_dq_in () &&retry<100)//am2305 pull down will again pull high 75~85us {retry++;
	Am2305_delay_us (1);
		} if (retry>=100) {uart_printf ("am2305:retry2:%d\r\n", retry);
	return FALSE;
} return TRUE; }



/*************************************************************************************************************			* Function: U8 am2305_readbit (void) * function: Read AM2305 1bit data * parameter: NO * return: Data * dependent : the underlying macro definition
* Author: cp1300@139.com * Time: 2014-09-20 * Last modified: 2014-09-20 * Description: ********************************** 			 
/U8 am2305_readbit (void)
	
	{U8 retry=0;
		while (am2305_dq_in () &&retry<80)//wait for the low level {retry++;
	Am2305_delay_us (1);
	}//if (RETRY&GT;=80)//{//uart_printf ("am2305:retry3:%d\r\n", retry);//} retry=0; while (!
		Am2305_dq_in () &&retry<60)//wait for high level {retry++;
	Am2305_delay_us (1);
	}//if (RETRY&GT;=60)//{//uart_printf ("am2305:retry4:%d\r\n", retry);//} Am2305_delay_us (38);
	if (am2305_dq_in ()) return 1;		
else return 0; }





/*************************************************************************************************************			* Function: U8 am2305_readbyte (void) * function: Reads a byte from the AM2305 * parameter: no * return: Read data * dependent : underlying macro definition * Author: cp1300@139.com * Time: 2014-09-20 * Last modified: 2014-09-20 * Description: No ****************************************************************************************************
    /U8 Am2305_readbyte (void) {U8 i,dat;
	dat=0; 
	    for (i=0;i<8;i++) {dat<<=1;
    Dat|=am2305_readbit ();
} return dat; }




/************************************************************************************************************* * Function: BOOL Am2305_readdata (S16 *ptemp,u16 *phumi) * Function: Read data from AM2305 * parameter: ptemp: Temperature pointer, Phumi: Humidity Data pointer * Return: FALSE: Read failed; TRUE: Read Success * dependency: underlying macro definition * Author: cp1300@139.com * Time: 2014-09-20 * Last modified: 2014-09-20 * Description: 2014-09-29: Fix negative temperature bug *******************************************************************************************************
	/bool Am2305_readdata (S16 *ptemp,u16 *phumi) {U8 buf[5];
	U8 I;
	
	U16 Utemp;
	Am2305_reset (); if (Am2305_check () ==true) {for (i=0;i<5;i++)//Read 40-bit data {buf[i]=am2305_readbyte ();
}////Uart_printf ("\nam2305:");
		for (i=0;i<5;i++)//Read 40-bit data//{//uart_printf ("0x%02x\t", Buf[i]);//}//uart_printf ("\ n");
			if ((U8) (buf[0]+buf[1]+buf[2]+buf[3]) ==buf[4]) {*phumi=buf[0];
			*phumi <<= 8;
			*PHUMI|=BUF[1];
			UTEMP=BUF[2];
			utemp<<=8;
			UTEMP|=BUF[3];
				if (Utemp > 0x8000) {utemp-= 0x8000;
			*ptemp = 0-utemp;
			} else {*ptemp = utemp;
		} return TRUE;
			} else {uart_printf ("AM2305 data check failed!\r\n");
		return FALSE;
		}} else {uart_printf ("AM2305 detection failed!\r\n");
	return FALSE; }    
}




/************************************************************************************************************ * Function: bool Am2305_init (void) * Function: Initialize AM2305, and detect existence * Parameters: None * return: FALSE: failed; TRUE: Success * Dependency: underlying macro definition * Author: cp1300@139.com * Time: 2014-09-20 * Last modified: 2014-09-20 * Description: No *********** ****/bool
	Am2305_init (void) {am2305_clk_init ();	
	Am2305_io_out ();
	Am2305_reset ();
return Am2305_check ();

 }

Header file

/*************************************************************************************************************
 * File name:			am2305.c
 * Function:			STM32 AM2305 High precision temperature and humidity sensor driver
 * Author:			cp1300@139.com
 * created on:		2014-09-20
 * Last modified:	2014-09-20
 * Verbose:			requires delay function support * Note that the 					delay accuracy is as high as possible
 * 					do not interrupt long periods of time when reading Because 1wire is very strict in time requirements
****************************************************************************************** /
#ifndef am2305_h_
#define Am2305_h_

#include "system.h"

#if (Board_ Support)	//requires board level
#include "board.h" 
#else	//default support

//PC3
#define Am2305_out		Pcout (3)
#define AM2305_IN		pcin (3)
//io
#define AM2305_DEV		dev_gpioc
#define AM2305 _gpiox	gpioc
#define AM2305_BITX		BIT3

#endif

void Am2305_powerdown (void);		AM2305 Power
-down bool Am2305_init (void);				AM2305 initialization of
bool Am2305_readdata (s16 *ptemp,u16 *phumi);	Reading temperature and humidity data




#endif/*am2305_h_*/

Reading temperature and humidity

Am2305_readdata (&temp, &hum);