Diff: communication_1.cpp

Revision:

2:b4d1f5424448

Child:

3:33d025a403d5

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/communication_1.cpp	Sun Jun 26 21:14:44 2016 +0000
@@ -0,0 +1,149 @@
+#include "communication_1.h"
+#include "mbed.h"
+
+#define READ_DEBUG 1
+
+communication_1::communication_1(PinName tx, PinName rx, int baud_rate) 
+: _SerialHalfDuplex(tx,rx) {
+        
+   _SerialHalfDuplex.baud(baud_rate);
+}
+
+int communication_1::read(int ID, int start, int bytes, char* data) {
+
+    char PacketLength = 0x4;
+    char TxBuf[16];
+    char sum = 0;
+    char Status[16];
+
+    Status[4] = 0xFE; // return code
+
+    TxBuf[0] = 0xff;
+    TxBuf[1] = 0xff;
+
+    // ID
+    TxBuf[2] = ID;
+    sum += TxBuf[2];
+
+    // Packet Length
+    TxBuf[3] = PacketLength;    // Length = 4 ; 2 + 1 (start) = 1 (bytes)
+    sum += TxBuf[3];            // Accululate the packet sum
+
+    // Instruction - Read
+    TxBuf[4] = 0x2;
+    sum += TxBuf[4];
+
+    // Start Address
+    TxBuf[5] = start;
+    sum += TxBuf[5];
+  
+    // Bytes to read
+    TxBuf[6] = bytes;
+    sum += TxBuf[6];
+   
+    // Checksum
+    TxBuf[7] = 0xFF - sum;
+
+    // Transmit the packet in one burst with no pausing
+    for (int i = 0; i<8 ; i++) {
+       // printf("Inizio scrittura numero %d\n",i);
+        _SerialHalfDuplex.putc(TxBuf[i]);
+         //printf("Fine scrittura numero %d\n",i);
+    }
+
+    // Wait for the bytes to be transmitted
+    wait (0.00002);
+
+    // Skip if the read was to the broadcast address
+    if (ID != 0xFE) {
+        // Receive the Status packet 6+ number of bytes read
+        for (int i=0; i<(6+bytes) ; i++) {
+            Status[i] = _SerialHalfDuplex.getc();
+        }
+
+        // Copy the data from Status into data for return
+        for (int i=0; i < Status[3]-2 ; i++) {
+            data[i] = Status[5+i];
+            }
+            
+        if (READ_DEBUG) {
+                printf("\nStatus Packet\n");
+                printf("  Header : 0x%x\n",Status[0]);
+                printf("  Header : 0x%x\n",Status[1]);
+                printf("  ID : 0x%x\n",Status[2]);
+                printf("  Length : 0x%x\n",Status[3]);
+                printf("  Error Code : 0x%x\n",Status[4]);
+    
+                for (int i=0; i < Status[3]-2 ; i++) {
+                    printf("  Data : 0x%x\n",Status[5+i]);
+                }    
+                printf("  Checksum : 0x%x\n",Status[5+(Status[3]-2)]);
+            }            
+    } // if (ID!=0xFE)
+    
+    return(Status[4]);
+}
+
+
+int communication_1::write(int ID, int start, int bytes, char* data, int flag) {
+// 0xff, 0xff, ID, Length, Intruction(write), Address, Param(s), Checksum
+
+    char TxBuf[16];
+    char sum = 0;
+    char Status[6];
+
+    TxBuf[0] = 0xff;
+    TxBuf[1] = 0xff;
+
+    // ID
+    TxBuf[2] = ID;
+    sum += TxBuf[2];
+
+    // packet Length
+    TxBuf[3] = 3+bytes;
+    sum += TxBuf[3];
+
+    // Instruction
+    if (flag == 1) {
+        TxBuf[4]=0x04;
+        sum += TxBuf[4];
+    } else {
+        TxBuf[4]=0x03;
+        sum += TxBuf[4];
+    }
+
+    // Start Address
+    TxBuf[5] = start;
+    sum += TxBuf[5];
+    
+    // data
+    for (int i=0; i<bytes ; i++) {
+        TxBuf[6+i] = data[i];
+        sum += TxBuf[6+i];
+    }
+
+    // checksum
+    TxBuf[6+bytes] = 0xFF - sum;
+
+    // Transmit the packet in one burst with no pausing
+    for (int i = 0; i < (7 + bytes) ; i++) {
+        _SerialHalfDuplex.putc(TxBuf[i]);
+    }
+
+    // Wait for data to transmit
+    wait (0.00002);
+
+    // make sure we have a valid return
+    Status[4]=0x00;
+
+    // we'll only get a reply if it was not broadcast
+    if (ID!=0xFE) {
+        // response is always 6 bytes
+        // 0xFF, 0xFF, ID, Length Error, Param(s) Checksum
+        for (int i=0; i < 6 ; i++) {
+            Status[i] = _SerialHalfDuplex.getc();
+        }
+        
+ return(Status[4]); // return error code
+
+}}
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