SHT2x系列数字温湿度传感器
SHT2x系列数字温湿度传感器
SHT2x系列和SHT1x系列相比电压范围缩小了（2.1~3.6V），同时功率明显比之前的系列要小。其它参数基本差不多。最大的区别就是传输模式了。比之前的要完善很多，支持标准的I2C了，调试起来更加顺手了。
<此处有待补充>
本着能不动手就少动手的原则，我在调试的时候用的是一个现成的程序，它是用IO口模拟I2C的。 代码如下：
前一个是头文件，后一个是函数实现。
1 #ifndef I2C_HAL_H 2 #define I2C_HAL_H 3 //============================================================================== 4 // S E N S I R I O N AG, Laubisruetistr. 50, CH-8712 Staefa, Switzerland 5 //============================================================================== 6 // Project : SHT2x Sample Code (V1.0) 7 // File : I2C_HAL.h 8 // Author : MST 9 // Controller: NEC V850/SG3 (uPD70F3740) 10 // Compiler : IAR compiler for V850 (3.50A) 11 // Brief : I2C Hardware abstraction layer 12 //============================================================================== 13 14 //---------- Includes ---------------------------------------------------------- 15 #include "system.h" 16 17 //---------- Defines ----------------------------------------------------------- 18 //I2C ports 19 //The communication on SDA and SCL is done by switching pad direction 20 //For a low level on SCL or SDA, direction is set to output. For a high level on 21 //SCL or SDA, direction is set to input. (pull up resistor active) 22 #define SDA PM3H_bit.no0 //SDA on I/O P38 defines direction (input=1/output=0) 23 #define SDA_CONF P3H_bit.no0 //SDA level on output direction 24 #define SCL PM3H_bit.no1 //SCL on I/O P39 defines direction (input=1/output=0) 25 #define SCL_CONF P3H_bit.no1 //SCL level on output direction 26 27 //---------- Enumerations ------------------------------------------------------ 28 // I2C level 29 typedef enum{ 30 LOW = 0, 31 HIGH = 1, 32 }etI2cLevel; 33 34 // I2C acknowledge 35 typedef enum{ 36 ACK = 0, 37 NO_ACK = 1, 38 }etI2cAck; 39 40 //============================================================================== 41 void I2c_Init (); 42 //============================================================================== 43 //Initializes the ports for I2C interface 44 45 //============================================================================== 46 void I2c_StartCondition (); 47 //============================================================================== 48 // writes a start condition on I2C-bus 49 // input : - 50 // output: - 51 // return: - 52 // note : timings (delay) may have to be changed for different microcontroller 53 // _____ 54 // SDA: |_____ 55 // _______ 56 // SCL : |___ 57 58 //============================================================================== 59 void I2c_StopCondition (); 60 //============================================================================== 61 // writes a stop condition on I2C-bus 62 // input : - 63 // output: - 64 // return: - 65 // note : timings (delay) may have to be changed for different microcontroller 66 // _____ 67 // SDA: _____| 68 // _______ 69 // SCL : ___| 70 71 //=========================================================================== 72 u8t I2c_WriteByte (u8t txByte); 73 //=========================================================================== 74 // writes a byte to I2C-bus and checks acknowledge 75 // input: txByte transmit byte 76 // output: - 77 // return: error 78 // note: timings (delay) may have to be changed for different microcontroller 79 80 //=========================================================================== 81 u8t I2c_ReadByte (etI2cAck ack); 82 //=========================================================================== 83 // reads a byte on I2C-bus 84 // input: rxByte receive byte 85 // output: rxByte 86 // note: timings (delay) may have to be changed for different microcontroller 87 88 #endif
1 //============================================================================== 2 // S E N S I R I O N AG, Laubisruetistr. 50, CH-8712 Staefa, Switzerland 3 //============================================================================== 4 // Project : SHT2x Sample Code (V1.0) 5 // File : I2C_HAL.c 6 // Author : MST 7 // Controller: NEC V850/SG3 (uPD70F3740) 8 // Compiler : IAR compiler for V850 (3.50A) 9 // Brief : I2C Hardware abstraction layer 10 //============================================================================== 11 12 //---------- Includes ---------------------------------------------------------- 13 #include "I2C_HAL.h" 14 15 //============================================================================== 16 void I2c_Init () 17 //============================================================================== 18 { 19 SDA=LOW; // Set port as output for configuration 20 SCL=LOW; // Set port as output for configuration 21 22 SDA_CONF=LOW; // Set SDA level as low for output mode 23 SCL_CONF=LOW; // Set SCL level as low for output mode 24 25 SDA=HIGH; // I2C-bus idle mode SDA released (input) 26 SCL=HIGH; // I2C-bus idle mode SCL released (input) 27 } 28 29 //============================================================================== 30 void I2c_StartCondition () 31 //============================================================================== 32 { 33 SDA=HIGH; 34 SCL=HIGH; 35 36 SDA=LOW; 37 DelayMicroSeconds(10); // hold time start condition (t_HD;STA) 38 SCL=LOW; 39 DelayMicroSeconds(10); 40 } 41 42 //============================================================================== 43 void I2c_StopCondition () 44 //============================================================================== 45 { 46 SDA=LOW; 47 SCL=LOW; 48 SCL=HIGH; 49 DelayMicroSeconds(10); // set-up time stop condition (t_SU;STO) 50 SDA=HIGH; 51 DelayMicroSeconds(10); 52 } 53 54 //============================================================================== 55 u8t I2c_WriteByte (u8t txByte) 56 //============================================================================== 57 { 58 u8t mask,error=0; 59 for (mask=0x80; mask>0; mask>>=1) //shift bit for masking (8 times) 60 { if ((mask & txByte) == 0) SDA=LOW;//masking txByte, write bit to SDA-Line 61 else SDA=HIGH; 62 DelayMicroSeconds(1); //data set-up time (t_SU;DAT) 63 SCL=HIGH; //generate clock pulse on SCL 64 DelayMicroSeconds(5); //SCL high time (t_HIGH) 65 SCL=LOW; 66 DelayMicroSeconds(1); //data hold time(t_HD;DAT) 67 } 68 SDA=HIGH; //release SDA-line 69 SCL=HIGH; //clk #9 for ack 70 DelayMicroSeconds(1); //data set-up time (t_SU;DAT) 71 if(SDA_CONF==HIGH) error=ACK_ERROR; //check ack from i2c slave 72 SCL=LOW; 73 DelayMicroSeconds(20); //wait time to see byte package on scope 74 return error; //return error code 75 } 76 77 //============================================================================== 78 u8t I2c_ReadByte (etI2cAck ack) 79 //============================================================================== 80 { 81 u8t mask,rxByte=0; 82 SDA=HIGH; //release SDA-line 83 for (mask=0x80; mask>0; mask>>=1) //shift bit for masking (8 times) 84 { SCL=HIGH; //start clock on SCL-line 85 DelayMicroSeconds(1); //data set-up time (t_SU;DAT) 86 DelayMicroSeconds(3); //SCL high time (t_HIGH) 87 if (SDA_CONF==1) rxByte=(rxByte | mask); //read bit 88 SCL=LOW; 89 DelayMicroSeconds(1); //data hold time(t_HD;DAT) 90 } 91 SDA=ack; //send acknowledge if necessary 92 DelayMicroSeconds(1); //data set-up time (t_SU;DAT) 93 SCL=HIGH; //clk #9 for ack 94 DelayMicroSeconds(5); //SCL high time (t_HIGH) 95 SCL=LOW; 96 SDA=HIGH; //release SDA-line 97 DelayMicroSeconds(20); //wait time to see byte package on scope 98 return rxByte; //return error code 99 }
