serialdata.cpp

00001 #include <mbed.h>
00002 
00003 extern Serial pc;
00004 
00005 void serialSend(float v) {
00006     pc.printf("aaaa"); // header
00007     unsigned char* data = (unsigned char*) &v;
00008     for (int i = 0; i < 4; i++) {
00009       pc.putc(data[i]);
00010     }
00011     pc.printf("\r\n"); // end of line
00012 }
00013 
00014 void serialSendVec(float vec[], int length) {
00015     pc.printf("aaaa"); // header
00016     unsigned char* data = (unsigned char*) vec;
00017     for (int i = 0; i < length*4; i++) {
00018       pc.putc(data[i]);
00019     }
00020     pc.printf("\r\n"); // end of line
00021 
00022 }
00023 
00024 enum RecvState {
00025     NONE,
00026     HEADER, 
00027     DATA, 
00028     END
00029 };
00030 
00031 float serialRecv() {
00032     RecvState state = NONE;
00033     int headerStep = 0;
00034     int dataStep = 0;
00035     bool receiving = 1;
00036     char buf[8];
00037     float v = -10;
00038     while(receiving) {
00039         char c = pc.getc();
00040         switch(state) {
00041             case NONE:
00042             case HEADER:
00043                 if(c == 'a') {
00044                     headerStep++;
00045                     if(headerStep == 4) {
00046                         state = DATA;
00047                         dataStep = 0;
00048                         v = 0;
00049                     }
00050                 } else {
00051                     headerStep = 0;
00052                 }
00053                 break;
00054             case DATA:
00055                 dataStep += 1;
00056                 buf[dataStep-1] = c;
00057                 if(dataStep == 4) {
00058                   state = END;
00059                   v = *(float*)buf;
00060                 }
00061                 break;
00062             case END: 
00063                 if(c == '\r' && pc.getc() == '\n') {
00064                   return v;
00065                 } else {
00066                   state = NONE;
00067                   headerStep = 0;
00068                 }
00069                 break;
00070         }
00071     }
00072     return v;
00073 }