求教!!有关Arduino和传感器的IIC通讯(MLX90615)
我正在利用MLX90615这个IR传感器测温度,利用I2C总线通讯,可是返回值总是相同,高位为254,低位为183。电路图
SDA,SCL参照数据手册引用320K上拉(数据手册建议300K,找不到300K电阻就用220K+100K.....)
代码
#include <i2cmaster.h>
void setup(){
Serial.begin(9600);
Serial.println("Setup...");
i2c_init(); //Initialise the i2c bus
}
void loop(){
int dev = 0x5B<<1;
int data_low = 0;
int data_high = 0;
int pec = 0;
i2c_start_wait(dev+I2C_WRITE);
i2c_write(0x07);
// read
i2c_rep_start(dev+I2C_READ);
data_low = i2c_readAck(); //Read 1 byte and then send ack
data_high = i2c_readAck(); //Read 1 byte and then send ack
pec = i2c_readNak();
i2c_stop();
//This converts high and low bytes together and processes temperature, MSB is a error bit and is ignored for temps
double tempFactor = 0.02; // 0.02 degrees per LSB (measurement resolution of the MLX90614)
double tempData = 0x0000; // zero out the data
int frac; // data past the decimal point
// This masks off the error bit of the high byte, then moves it left 8 bits and adds the low byte.
tempData = (double)(((data_high & 0x007F) << 8) + data_low);
tempData = (tempData * tempFactor)-0.01;
float celcius = tempData - 273.15;
float fahrenheit = (celcius*1.8) + 32;
Serial.print("Celcius: ");
Serial.println(celcius);
delay(1000); // wait a second before printing again
}代码根据http://bildr.org/2011/02/mlx90614-arduino/里提供的MLX90614的代码修改,就是把设备地址改成了0x5B,614和615除了引脚位置不同以外好像就没有差别了。。。。
问题在于我的615无法正常工作。。。。不知道为什么
实物图:
串口监视器输出结果
在此请教各位大神!!
没研究过这个,话说楼主为何不用自带的I2C的库呢看看这个帖子能否帮到楼主?http://www.amobbs.com/thread-3990328-1-1.html
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