51单片机红外遥控解码



红外遥控发射芯片采用PPM编码方式,当发射器按键按下后,将发射一组108ms的编码脉冲。遥控编码脉冲由前导码、8位用户码、8位用户码的反码、8位操作码以及8位操作码的反码组成。通过对用户码的检验，每个遥控器只能控制一个设备动作，这样可以有效地防止多个设备之间的干扰。编码后面还要有编码的反码，用来检验编码接收的正确性，防止误操作，增强系统的可靠性。前导码是一个遥控码的起始部分，由一个9ms的低电平(起始码)和一个4. 5ms的高电平(结果码)组成，作为接受数据的准备脉冲。以脉宽为0. 56ms、周期为1. 12ms的组合表示二进制的“0”；以脉宽为1. 68ms、周期为2. 24ms的组合表示二进制的“1”。如果按键按下超过108ms仍未松开,接下来发射的代码(连发代码)将仅由起始码(9ms)和结束码(2. 5ms)组成。



单片机采用外部中断INTI管脚和红外接收头的信号线相连，中断方式为边沿触发方式。并用定时器0计算中断的间隔时间，来区分前导码、二进制的“1”、“0”码。并将8位操作码提取出来在数码管上显示。-51 single-chip infrared remote control decoding



Infrared remote control transmitter chip PPM encoding, when the transmitter button is pressed, will launch the encoding of a group of 108ms pulse. The remote encoder pulse from the preamble, eight user codes and eight user codes Anti-code, eight opcode and the 8-bit opcode inverted. Test the user code, the action of each remote control can only control one device, so you can effectively prevent interference between multiple devices. Coded later encoded anti-code, used to test the code to receive the correctness, to prevent misuse, enhance system reliability. The preamble is the start of a remote control code by a 9ms low (start code) and a 4-5ms high (result code), as a data ready pulse. Pulse width 56ms, cycle 12ms combination of binary "0"　pulse width is 1. 68ms cycle. The 24ms combination of that binary "1". If the button is pressed for more than 108ms yet to release the next launch of the code (fire code) will only start code (9m