家居智能系统中通常要使用红外遥控去控制各种家电，如：电视、机顶盒、空调、电风扇等，家电往往分布在家庭的各个不同房间，而红外信号是无法穿墙去控制家电，怎么样让红外信号“穿墙”，这是所有智能家居系统必须解决的问题。
我的解决方案是使用NRF24L01无线通信模块来进行红外信号“穿墙”，基本思路是：在家居智能主机上插上一片NRF24L01，而红外穿墙控制分机同样装有NRF24L01，分机的功能是用于接收主机主机发来的红外遥控信号，并将这个信号通过分机上的红外发光二极管发送出去。
我们采集到的红外遥控信号是一个时间序列，保存在一个uint16_t的数组中，这个数组根据遥控信号不同，从长度为几十到几百不等，比如美的遥控信号的时间序列通常在200个左右。而NRF24L01每次能够可靠传输的数据包最大是32个字节，要通过它传输几百个字节的数据才能解决红外信号穿墙的问题，为此我设计了一个简单的流式传输协议来通过NRF24L01进行可靠数据的传输，相应的函数原型：
uint8_t NRF24L01_Send(uint8_t *buf, uint16_t len);
uint16_t NRF24L01_Recv(uint8_t *buf, uint16_t len);
由于这两个函数传输的是uint8_t的数组，而红外信号的时间序列是uint16_t的数组，为了将信号通过无线模块进行传输，我还特地设计了两个转换函数：
void word2ByteArray(uint16_t *buf, uint16_t len, uint8_t *bBuf);
void byte2WordArray(uint8_t *bBuf, uint16_t bLen, uint16_t *buf);
有了上述一些基础准备，接下来实现红外穿墙控制就水到渠成了。
为了验证我的这个方案，特地设计了一个模拟的家居智能“主机”，这个主机功能非常简单：接收来自串口的输入，如果串口输入1，则向分机发送开空调的红外信号，让隔壁的空调打开；如果输入0，则向分机发送关空调的红外信号，让隔壁的空调关机。在软件包的“Projects\NRF24L01-SendLong”文件夹包含了这个程序的完整工程，可以直接编译、烧写和调试。程序代码如下：
#include "WProgram.h"
#include "24l01.h"
#include "stdlib_ex.h"
//美的空调：开
uint16_t rawData_1[] =
{4486,4428,590,1604,590,534,563,1605,591,1603,592,533,563,535,563,1604,591,535,563,534,564,1606,589,
534,563,535,563,1604,590,1603,592,535,563,1604,591,1607,588,535,563,1605,590,1607,588,1604,591,1632,
564,1602,593,1605,591,534,563,1602,593,534,563,534,563,534,563,535,563,534,563,534,563,1604,591,534,
563,1632,563,534,564,1604,590,1605,590,534,563,534,564,534,563,1605,591,533,563,1604,591,535,563,534,
563,1605,590,1604,592,5263,4512,4427,592,1602,593,534,563,1602,593,1632,563,535,563,534,563,1605,
590,535,564,533,563,1607,589,534,563,534,563,1604,592,1602,593,534,563,1604,591,1630,564,534,563,
1631,564,1604,591,1604,592,1603,592,1604,591,1633,563,534,563,1604,592,534,563,535,563,510,587,534,
563,534,564,510,587,1630,565,510,587,1631,564,511,586,1603,592,1604,591,511,587,511,587,509,588,1605,
590,510,587,1603,593,510,587,511,587,1603,592,1604,591};
//美的空调：关
uint16_t rawData_0[] =
{4464,4451,567,1628,567,532,565,1628,567,1629,567,531,565,532,567,1626,568,531,566,532,565,1628,568,
532,565,532,566,1627,568,1630,565,532,566,1627,568,532,566,1629,566,1628,567,1629,567,1628,567,532,
565,1629,567,1627,568,1628,567,531,567,531,565,532,566,532,565,1627,568,531,566,532,566,1628,567,
1629,566,1627,568,533,565,532,565,532,566,531,566,532,566,531,565,533,565,532,565,1627,568,1629,567,
1629,567,1628,567,1627,568,5286,4489,4452,567,1629,566,532,566,1628,568,1627,568,531,566,531,566,
1628,568,530,566,531,565,1629,567,532,565,532,565,1630,566,1629,567,532,565,1628,567,533,565,1629,
567,1628,567,1628,592,1604,590,508,577,1616,577,1620,590,1603,567,533,589,508,589,509,589,508,589,
1603,592,508,590,507,590,1603,591,1633,562,1543,652,509,589,509,588,509,589,508,590,508,589,508,590,
507,589,508,589,1605,590,1604,591,1604,591,1604,592,1604,592};
uint16_t len1 = sizeof(rawData_1)/sizeof(uint16_t);
uint16_t len0 = sizeof(rawData_0)/sizeof(uint16_t);
void setup()
{
//初始化Rainbow
boardInit();
//初始化默认串口
Serial.begin();
//初始化无线通信模块
NRF24L01_Init();
Serial.println("NRF24L01-SendLong start...");
}
void loop()
{
uint8_t *bRawData;
if(Serial.available())
{
switch(Serial.read())
{
case 0x30:
bRawData = new uint8_t[2*len0];
word2ByteArray(rawData_0, len0, bRawData);
//关空调
if(NRF24L01_Send(bRawData, 2*len0))
Serial.println("Close conditioner...");
delete []bRawData;
break;
case 0x31:
bRawData = new uint8_t[2*len1];
word2ByteArray(rawData_1, len1, bRawData);
//开空调
if(NRF24L01_Send(bRawData, 2*len1))
Serial.println("Open conditioner...");
delete []bRawData;
break;
}
}
}
int main()
{
setup();
while(1) loop();
}
红外信号穿墙控制分机的功能则非常简单，仅仅就是接收NRF24L01发来的红外遥控时间序列，然后通过红外发光二极管发送出去。在软件包的“Projects\NRF24L01-RecvLong”文件夹包含了红外穿墙分机的完整工程，可以直接编译、烧写和调试。程序代码如下：
#include "WProgram.h"
#include "24l01.h"
#include "stdlib_ex.h"
#include "IRRemote.h"
//接收缓冲的大小
#define RECV_BUF_LEN 800
uint8_t buf[RECV_BUF_LEN];
//定义红外发射对象，红外发光二极管接到TIM2的CH1，即：PB8
IRSend irSend;
void setup()
{
//初始化Rainbow
boardInit();
//初始化默认串口
Serial.begin();
//初始化无线通信模块
NRF24L01_Init();
//用38K的载波进行调制
irSend.enableIROut(38);
Serial.println("NRF24L01-RecvLong start...");
}
void loop()
{
//接收到对方发来的数据
uint16_t wBuf[RECV_BUF_LEN/2];
uint16_t len = NRF24L01_Recv(buf, RECV_BUF_LEN);
if(len > 0)
{
//收到的byte数组，转化成红外遥控的uint16_t数组
byte2WordArray(buf, len, wBuf);
irSend.sendRaw(wBuf, len/2);
}
}
int main()
{
setup();
while(1) loop();
}