PIC单片机滚动码解码C程序.docVIP

//PIC单片机滚动码解码C程序 // Interrupt based receive routine // Compiled using HiTech PIC C compiler v.7.93 #define CLOCK 4 // MHz #define TE 400 // us #define OVERSAMPLING 3 // #define PERIOD //TE/OVERSAMPLING*4/CLOCK #define NBIT 65 // number of bit to receive -1 HCS300 66-1 65 unsigned char B[9]; // receive buffer static byte RFstate; // receiver state static sbyte RFcount; // timer counter static byte Bptr; // receive buffer pointer static byte BitCount; // received bits counter word XTMR; // 16 bit extended timer volatile bit RFFull; // buffer full volatile bit RFBit; // sampled RF signal #define TRFreset 0 #define TRFSYNC 1 #define TRFUNO 2 #define TRFZERO 3 #define HIGH_TO -10 // longest high Te #define LOW_TO 10 // longest low Te #define SHORT_HEAD 20 // shortest Thead accepted 2,7ms #define LONG_HEAD 45 // longest Thead accepted 6,2ms // #pragma int_rtcc // install as interrupt handler comment for HiTech! void interrupt rxi void //this routine gets called every time TMR0 overflows RFBit RFIn; // sampling RF pin verify!!! TMR0 - PERIOD; // reload; T0IF 0; XTMR++; // extended 16 long timer update; // if RFFull // avoid overrun; return; switch RFstate // state machine main switch case TRFUNO: if RFBit // while high RFcount--; if RFcount HIGH_TO RFstate TRFreset; // reset if too long else // falling edge detected // // RFstate TRFZERO; break; case TRFZERO: if RFBit // rising edge detected // // RFstate TRFUNO; B[Bptr] 1; // rotate if RFcount 0 B[Bptr]+ 0x80; // shift in bit RFcount 0; // reset length counter if ++BitCount 7 0 Bptr++; // advance one byte if BitCount NBIT RFstate TRFreset; // finished receiving RFFull TRUE; else // still low RFcount++; if RFcount LOW_TO // too long low RFstate TRFSYNC; // fall back into RFSYNC state Bptr 0; // reset pointers, while keep counting on BitCount 0; break; case TRFSYNC: if RFBit // rising edge detected // // if RFcount SHORT_HEAD || RFcount LONG_HEAD