communication_1.cpp

00001 #include "communication_1.h"
00002 #include "mbed.h"
00003 
00004 #define READ_DEBUG 1
00005 #define WRITE_DEBUG 1
00006 #define TRIGGER_DEBUG 0
00007 
00008 communication_1::communication_1(PinName tx, PinName rx, int baud_rate) 
00009   : _SerialHalfDuplex(tx,rx) {
00010 
00011     _SerialHalfDuplex.baud(baud_rate);
00012   }
00013 
00014 int communication_1::read(int ID, int start, int bytes, char* data) {
00015 
00016   char PacketLength = 0x4;
00017   char TxBuf[16];
00018   char sum = 0;
00019   char Status[16];
00020 
00021   Status[4] = 0xFE; // return code
00022 
00023   TxBuf[0] = 0xff;
00024   TxBuf[1] = 0xff;
00025 
00026   // ID
00027   TxBuf[2] = ID;
00028   sum += TxBuf[2];
00029 
00030   // Packet Length
00031   TxBuf[3] = PacketLength;    // Length = 4 ; 2 + 1 (start) = 1 (bytes)
00032   sum += TxBuf[3];            // Accululate the packet sum
00033 
00034   // Instruction - Read
00035   TxBuf[4] = 0x2;
00036   sum += TxBuf[4];
00037 
00038   // Start Address
00039   TxBuf[5] = start;
00040   sum += TxBuf[5];
00041 
00042   // Bytes to read
00043   TxBuf[6] = bytes;
00044   sum += TxBuf[6];
00045 
00046   // Checksum
00047   TxBuf[7] = 0xFF - sum;
00048 
00049   // Transmit the packet in one burst with no pausing
00050   for (int i = 0; i<8 ; i++) {
00051     // printf("Inizio scrittura numero %d\n",i);
00052     _SerialHalfDuplex.putc(TxBuf[i]);
00053     //printf("Fine scrittura numero %d\n",i);
00054   }
00055 
00056   // Wait for the bytes to be transmitted
00057   wait (0.00002);
00058 
00059   // Skip if the read was to the broadcast address
00060   if (ID != 0xFE) {
00061     // Receive the Status packet 6+ number of bytes read
00062     for (int i=0; i<(6+bytes) ; i++) {
00063       Status[i] = _SerialHalfDuplex.getc();
00064     }
00065 
00066     // Copy the data from Status into data for return
00067     for (int i=0; i < Status[3]-2 ; i++) {
00068       data[i] = Status[5+i];
00069     }
00070 
00071     if (READ_DEBUG) {
00072       printf("\nStatus Packet\n");
00073       printf("  Header : 0x%x\n",Status[0]);
00074       printf("  Header : 0x%x\n",Status[1]);
00075       printf("  ID : 0x%x\n",Status[2]);
00076       printf("  Length : 0x%x\n",Status[3]);
00077       printf("  Error Code : 0x%x\n",Status[4]);
00078 
00079       for (int i=0; i < Status[3]-2 ; i++) {
00080         printf("  Data : 0x%x\n",Status[5+i]);
00081       }    
00082       printf("  Checksum : 0x%x\n",Status[5+(Status[3]-2)]);
00083     }            
00084   } // if (ID!=0xFE)
00085 
00086   return(Status[4]);
00087 }
00088 
00089 
00090 int communication_1::write(int ID, int start, int bytes, char* data, int flag) {
00091   // 0xff, 0xff, ID, Length, Intruction(write), Address, Param(s), Checksum
00092 
00093   char TxBuf[16];
00094   char sum = 0;
00095   char Status[6];
00096 
00097   TxBuf[0] = 0xff;
00098   TxBuf[1] = 0xff;
00099 
00100   // ID
00101   TxBuf[2] = ID;
00102   sum += TxBuf[2];
00103 
00104   // packet Length
00105   TxBuf[3] = 3+bytes;
00106   sum += TxBuf[3];
00107 
00108   // Instruction
00109   if (flag == 1) {
00110     TxBuf[4]=0x04;
00111     sum += TxBuf[4];
00112   } else {
00113     TxBuf[4]=0x03;
00114     sum += TxBuf[4];
00115   }
00116 
00117   // Start Address
00118   TxBuf[5] = start;
00119   sum += TxBuf[5];
00120 
00121   // data
00122   for (int i=0; i<bytes ; i++) {
00123     TxBuf[6+i] = data[i];
00124     sum += TxBuf[6+i];
00125   }
00126 
00127   // checksum
00128   TxBuf[6+bytes] = 0xFF - sum;
00129 
00130   // Transmit the packet in one burst with no pausing
00131   for (int i = 0; i < (7 + bytes) ; i++) {
00132     _SerialHalfDuplex.putc(TxBuf[i]);
00133   }
00134 
00135   // Wait for data to transmit
00136   wait (0.00002);
00137 
00138   // make sure we have a valid return
00139   Status[4]=0x00;
00140   return(Status[4]);
00141 
00142   // we'll only get a reply if it was not broadcast
00143   //if (ID!=0xFE) {
00144     // response is always 6 bytes
00145     // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
00146     //for (int i=0; i < 6 ; i++) {
00147       //Status[i] = _SerialHalfDuplex.getc();
00148     //}
00149 
00150     //return(Status[4]); // return error code
00151 
00152   //}
00153 }
00154 
00155 void communication_1::trigger(void) {
00156 
00157   char TxBuf[16];
00158   char sum = 0;
00159 
00160   if (TRIGGER_DEBUG) {
00161     printf("\nTriggered\n");
00162   }
00163 
00164   // Build the TxPacket first in RAM, then we'll send in one go
00165   if (TRIGGER_DEBUG) {
00166     printf("\nTrigger Packet\n  Header : 0xFF, 0xFF\n");
00167   }
00168 
00169   TxBuf[0] = 0xFF;
00170   TxBuf[1] = 0xFF;
00171 
00172   // ID - Broadcast
00173   TxBuf[2] = 0xFE;
00174   sum += TxBuf[2];
00175 
00176   if (TRIGGER_DEBUG) {
00177     printf("  ID : %d\n",TxBuf[2]);
00178   }
00179 
00180   // Length
00181   TxBuf[3] = 0x02;
00182   sum += TxBuf[3];
00183   if (TRIGGER_DEBUG) {
00184     printf("  Length %d\n",TxBuf[3]);
00185   }
00186 
00187   // Instruction - ACTION
00188   TxBuf[4] = 0x04;
00189   sum += TxBuf[4];
00190   if (TRIGGER_DEBUG) {
00191     printf("  Instruction 0x%X\n",TxBuf[5]);
00192   }
00193 
00194   // Checksum
00195   TxBuf[5] = 0xFF - sum;
00196   if (TRIGGER_DEBUG) {
00197     printf("  Checksum 0x%X\n",TxBuf[5]);
00198   }
00199 
00200   // Transmit the packet in one burst with no pausing
00201   for (int i = 0; i < 6 ; i++) {
00202     _SerialHalfDuplex.putc(TxBuf[i]);
00203   }
00204 
00205   // This is a broadcast packet, so there will be no reply
00206 
00207   return;
00208 }