X-Git-Url: http://git.smho.de/gw/?p=owSlave2.git;a=blobdiff_plain;f=common%2FI2C%2FSHT2xV2.c;fp=common%2FI2C%2FSHT2xV2.c;h=130e85bff1d74e7210370d631ea05e26b4d046b0;hp=0000000000000000000000000000000000000000;hb=a07a7e7b05471927bf3046ee265792231711f8a4;hpb=286630139d0e6355ad62c7cbb0c9fe827cbb7fa7

diff --git a/common/I2C/SHT2xV2.c b/common/I2C/SHT2xV2.c
new file mode 100644
index 0000000..130e85b
--- /dev/null
+++ b/common/I2C/SHT2xV2.c
@@ -0,0 +1,105 @@
+// Copyright (c) 2017, Tobias Mueller tm(at)tm3d.de
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//  * Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+//  * Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the
+//    distribution.
+//  * All advertising materials mentioning features or use of this
+//    software must display the following acknowledgement: This product
+//    includes software developed by tm3d.de and its contributors.
+//  * Neither the name of tm3d.de nor the names of its contributors may
+//    be used to endorse or promote products derived from this software
+//    without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+#define F_CPU 8000000UL
+#include <avr/io.h>
+#include <util/delay.h>
+#include "USI_TWI_Master.h"
+#include "SHT2xV2.h"
+
+uint8_t initSHT2x(){
+
+	I2c_StartCondition();
+	I2c_WriteByte(0b10000000);
+	I2c_WriteByte(0xFE);//Softreset 
+	I2c_StopCondition();
+	//Default 12 Bit RH 14 Bit T
+	return 1;
+}
+
+uint8_t crcmove(uint8_t crc) {
+	uint8_t bit;
+	for(bit=8;bit>0;--bit) {
+		if (crc&0x80) crc=(crc<<1)^  0x131;
+		else crc=(crc<<1);
+	}
+	return crc;
+}
+
+uint8_t calcCRCSHT2x(uint8_t b1, uint8_t b2) {
+	uint8_t crc=0;
+	crc^=b1;
+	crc=crcmove(crc);
+	crc^=b2;
+	return crcmove(crc);
+	
+}
+
+
+
+uint8_t getSHT2xHumTemp(double *temp,double *hum) {
+	uint8_t ret=1;
+	I2c_StartCondition();
+	I2c_WriteByte(0b10000000);
+	I2c_WriteByte(0xF3); //No Hold Temp
+	_delay_us(20);
+	I2c_StopCondition();
+	_delay_ms(85);
+	I2c_StartCondition();
+	I2c_WriteByte (0b10000001);
+	uint8_t t1 =I2c_ReadByte(ACK);
+	uint8_t t2 =I2c_ReadByte(ACK);
+	uint8_t tc =I2c_ReadByte(NO_ACK);
+	I2c_StopCondition();
+
+	I2c_StartCondition();
+	I2c_WriteByte(0b10000000);
+	I2c_WriteByte(0xF5); //No Hold Hum
+	_delay_us(20);
+	I2c_StopCondition();
+	_delay_ms(29);
+	I2c_StartCondition();
+	I2c_WriteByte (0b10000001);
+	uint8_t f1 =I2c_ReadByte(ACK);
+	uint8_t f2 =I2c_ReadByte(ACK);
+	uint8_t fc =I2c_ReadByte(NO_ACK);
+	I2c_StopCondition();
+	if (calcCRCSHT2x(t1,t2)==tc)
+		*temp=-46.85 + 175.72/65536 *(double)(((uint16_t)t1<<8)|(t2&0xF8));
+	else ret=0;
+	if (calcCRCSHT2x(f1,f2)==fc)
+		*hum=-6.0+125.0/65536*(double)(((uint16_t)f1<<8)|(f2&0xF8));
+	else ret=0;
+	return ret;
+}
+