我正在尝试使用Arduino Uno/ESP8266在38KHz载波频率上生成红外信号来替代红外遥控器。
首先，我尝试使用IRremote.h库，但是当我使用“irsend.sendNEC（0x8F4567A2, 32）”发送代码时，实际接收到的IR代码不是8F4567A2（使用IRrecvDump示例）。因此，我使用示波器将发射器引脚连接起来以检查Arduino/Esp8266生成的信号是什么。我注意到载波脉冲持续时间超过100us（38KHz应该约为26us）。
然后，我找到了YouTube教程，教人们如何手动生成信号而不使用IRremote库，代码如下。我仍然将示波器与发射器引脚连接起来，并发现载波脉冲持续时间超过100us，即使我在sketch中设置为26us，我也无法看到平坦的脉冲宽度，即使我设置了方波脉冲。但如果我只是简单地在loop（）中放置“IRcarrier（260）”，并删除循环中的所有其他代码，示波器每5秒钟就会显示正确的脉冲持续时间，并且脉冲会像预期的那样显示出来。
我在我的红外项目中遇到了困难，试图使用arduino / esp8266来替换电视红外遥控器。
#define IRLEDpin 2 //the arduino pin connected to IR LED to ground. HIGH=LED ON
#define BITtime 562 //length of the carrier bit in microseconds
//put your own code here - 4 bytes (ADDR1 | ADDR2 | COMMAND1 | COMMAND2)
unsigned long IRcode=0b11000001110001111100000000111111;
// SOME CODES:
// Canon WL-D89 video remote START/STOP button = 0b11000001110001111100000000111111
void setup()
{
}
void IRsetup(void)
{
pinMode(IRLEDpin, OUTPUT);
digitalWrite(IRLEDpin, LOW); //turn off IR LED to start
}
// Ouput the 38KHz carrier frequency for the required time in microseconds
// This is timing critial and just do-able on an Arduino using the standard I/O functions.
// If you are using interrupts, ensure they disabled for the duration.
void IRcarrier(unsigned int IRtimemicroseconds)
{
for(int i=0; i < (IRtimemicroseconds / 26); i++)
{
digitalWrite(IRLEDpin, HIGH); //turn on the IR LED
//NOTE: digitalWrite takes about 3.5us to execute, so we need to factor that into the timing.
delayMicroseconds(9); //delay for 13us (9us + digitalWrite), half the carrier frequnecy
digitalWrite(IRLEDpin, LOW); //turn off the IR LED
delayMicroseconds(9); //delay for 13us (9us + digitalWrite), half the carrier frequnecy
}
}
//Sends the IR code in 4 byte NEC format
void IRsendCode(unsigned long code)
{
//send the leading pulse
IRcarrier(9000); //9ms of carrier
delayMicroseconds(4500); //4.5ms of silence
//send the user defined 4 byte/32bit code
for (int i=0; i<32; i++) //send all 4 bytes or 32 bits
{
IRcarrier(BITtime); //turn on the carrier for one bit time
if (code & 0x80000000) //get the current bit by masking all but the MSB
delayMicroseconds(3 * BITtime); //a HIGH is 3 bit time periods
else
delayMicroseconds(BITtime); //a LOW is only 1 bit time period
code<<=1; //shift to the next bit for this byte
}
IRcarrier(BITtime); //send a single STOP bit.
}
void loop() //some demo main code
{
IRsetup(); //Only need to call this once to setup
IRsendCode(IRcode);
delay(5000);
}