红外编码与解码——GREE格力遥控 发送



红外编码与解码——GREE格力遥控 发送在上一期上描述了红外解码，以及红外在传播过程中造成的误差，

上期回顾

[红外]02、红外编码与解码——GREE格力遥控 http://bbs.eeworld.com.cn/thread-462015-1-1.html

针对GREE格力遥控的红外编码的原则
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进行编码如下

代码如下：

void IRsend_sendGREE(long datavalue ,unsigned int greeCRC)
{
  long data = 0;
  long temp = 0;
  IRsend_enableIROut(38);
  IRsend_mark(GREE_HDR_MARK);
  IRsend_space(GREE_HDR_SPACE);
  data = (datavalue&0xffffff80)|0x0A;
  for (int i = 0; i < 32; i++){
      if (data & TOPBIT) {
      IRsend_mark(GREE_BIT_MARK);
      IRsend_space(GREE_ONE_SPACE);
    }
    else {
      IRsend_mark(GREE_BIT_MARK);
      IRsend_space(GREE_ZERO_SPACE);
    }
    data <<= 1;
  }
  data = 0×02;
  for (int i = 0; i < 3; i++){
      if (data & TOPBIT) {
      IRsend_mark(GREE_BIT_MARK);
      IRsend_space(GREE_ONE_SPACE);
    }
    else {
      IRsend_mark(GREE_BIT_MARK);
      IRsend_space(GREE_ZERO_SPACE);
    }
    data <<= 1;
  }
  
  IRsend_mark(GREE_COM_MARK);
  IRsend_space(GREE_COM_SPACE);  
  
  temp = datavalue&0×00000040;//7
  data = (temp>>6);
  data = data<<4;
  temp = datavalue&0×00000020;//6
  data = data|(temp>>5);
  data = data<<5;
  temp = datavalue&0×00000018;//5 4
  data = data|(temp>>3);
  data = ((data<<16)|0×1000)<<1;//3
  temp = datavalue&0×00000004;
  data = data|(temp>>2);
  data = (data<<5)|(greeCRC&0x000f);
  for (int i = 0; i < 32; i++){
      if (data & TOPBIT) {
      IRsend_mark(GREE_BIT_MARK);
      IRsend_space(GREE_ONE_SPACE);
    }
    else {
      IRsend_mark(GREE_BIT_MARK);
      IRsend_space(GREE_ZERO_SPACE);
    }
    data <<= 1;
  }
  
  IRsend_mark(GREE_BIT_MARK);
  IRsend_space(0);
}

IRsend_enableIROut 主要实现的功能是配置PWM波的载波频率，一般为38KHZ  1/3~1/4Duty (当然也有一些特别)

由[红外]01、红外遥控介绍与接收http://bbs.eeworld.com.cn/thread-461935-1-1.html可知

要发出红外波，就是以PWM驱动红外LED传播红外波
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其代码如下：

void Sct_Pwm_Init(uint32_t PWM_RATE)
{
    /* Initialize the SCT as PWM and set frequency */
Chip_SCTPWM_Init(LPC_SCT);
Chip_SCTPWM_SetRate(LPC_SCT, PWM_RATE);
/* Setup Board specific output pin */
Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 9, IOCON_FUNC2 | IOCON_MODE_INACT | IOCON_DIGITAL_EN | IOCON_INPFILT_OFF);
/* Use SCT0_OUT1 pin */
Chip_SCTPWM_SetOutPin(LPC_SCT, SCT_PWM_OUT, SCT_PWM_PIN_OUT);
/* Start with 0% duty cycle */
Chip_SCTPWM_SetDutyCycle(LPC_SCT, SCT_PWM_OUT, Chip_SCTPWM_GetTicksPerCycle(LPC_SCT) / 4);
//Chip_SCTPWM_Start(LPC_SCT);
}

void IRsend_mark(int time) {
  // Sends an IR IRsend_mark for the specified number of microseconds.
  // The IRsend_mark output is modulated at the PWM frequency.
  TIMER_ENABLE_PWM(); // Enable pin 3 PWM output
  if (time > 0) delayMicros(time);
}
/* Leave pin off for time (given in microseconds) */
void IRsend_space(int time) {
  // Sends an IR IRsend_space for the specified number of microseconds.
  // A IRsend_space is no output, so the PWM output is disabled.
  TIMER_DISABLE_PWM(); // Disable pin 3 PWM output
  if (time > 0) delayMicros(time);
}

由[红外]02、红外编码与解码——GREE格力遥控 http://bbs.eeworld.com.cn/thread-462015-1-1.html
解译出的代码
以开/关键为理
关IRsend_sendGREE(0×900400,0xa);
开IRsend_sendGREE(0X10900400,0xb);


用数据采集仪分析对比

LPC54102 发送出来
file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Application%20Data/YNote/data/1696933323@qq.com/25105f09d6fb4f1eb6d1452cd3f70040/clipboard.png


file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Application%20Data/YNote/data/1696933323@qq.com/13cbcd67b3f84aca9be613ffeadc10ae/clipboard.png

遥控器



file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Application%20Data/YNote/data/1696933323@qq.com/1f6cd68b1f004a78bc7af0f0451c55a5/clipboard.png

仔细对比，校对得以上图。

最后上电测试 成功的开关空调。总结对于LPC54102的资源为 PWM 的输出，定时器（延时）。其实软件延时也可以。下图为非准确延时的图，都能实现开关机

不对资源不是很紧张或者是初调试者建议还是用定时器延时。用到的资源主要有
LPC_SCT 与LPC_TIMER2