Prosper Van / xbeeCom

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Fork of com by Prosper Van

com.cpp@12:bf4642578682, 2014-04-26 (annotated)

Committer:
oprospero
Date:
Sat Apr 26 02:38:08 2014 +0000
Revision:
12:bf4642578682
Parent:
11:d1f488302d06
Child:
13:2fb7b19dcd70
initial changed from orginal

Who changed what in which revision?

UserRevisionLine numberNew contents of line
oprospero 0:26a151d2c6db 1 /****************************** com.cpp **********************************/
oprospero 0:26a151d2c6db 2 /* Version: 1.0 */
oprospero 0:26a151d2c6db 3 /* Last Updated: June 1, 2013 */
oprospero 0:26a151d2c6db 4 /* */
oprospero 0:26a151d2c6db 5 /* The com class implements reliable data transfer between two nodes */
oprospero 0:26a151d2c6db 6 /*using a checksum and a sequence number for guaranteed message delivery */
oprospero 0:26a151d2c6db 7 /*over an xbee modem connected to the passed in tx and rx pins. Messages */
oprospero 0:26a151d2c6db 8 /*are received and placed in the rxBuffer to be read when convenient. */
oprospero 0:26a151d2c6db 9 /*Messages are encoded by sending a byte with the value of the command */
oprospero 0:26a151d2c6db 10 /*then and int of the command. */
oprospero 0:26a151d2c6db 11 /* */
oprospero 0:26a151d2c6db 12 /* Commands: 0 -> Ack, does not get placed in rxQueue. */
oprospero 0:26a151d2c6db 13 /* 1 -> Throttle */
oprospero 0:26a151d2c6db 14 /* 2 -> Pitch */
oprospero 0:26a151d2c6db 15 /* 3 -> Roll */
oprospero 0:26a151d2c6db 16 /* 4 -> Yaw */
oprospero 0:26a151d2c6db 17 /*************************************************************************/
oprospero 0:26a151d2c6db 18
oprospero 0:26a151d2c6db 19 #include "mbed.h"
oprospero 0:26a151d2c6db 20 #include "com.h"
oprospero 0:26a151d2c6db 21
oprospero 1:4f53de75bc96 22
oprospero 0:26a151d2c6db 23 /*********************** com( PinName, PinName ) *************************/
oprospero 0:26a151d2c6db 24 /* */
oprospero 0:26a151d2c6db 25 /*************************************************************************/
oprospero 0:26a151d2c6db 26
oprospero 2:bd1621102cad 27 com::com( PinName tx, PinName rx , PinName rssipin) : xbeeTx( tx, NC), xbeeRx( NC, rx), rssi(rssipin)
oprospero 0:26a151d2c6db 28 {
oprospero 12:bf4642578682 29 index1 = 0; // How many bytes are in the buffer.
oprospero 12:bf4642578682 30 index2 = 0; // How many bytes are in the buffer.
oprospero 12:bf4642578682 31 pindex = 0; // How many bytes are in the buffer.
oprospero 12:bf4642578682 32 rdy2build = false; // Xbee is in transparent mode.
oprospero 1:4f53de75bc96 33 xbeeTx.baud(BAUDRATE); // Setup the serial baud rate.
oprospero 0:26a151d2c6db 34 xbeeRx.baud(BAUDRATE); // Setup the serial baud rate.
oprospero 5:7cdf299ea7a4 35 txBuffer = new queue();
oprospero 0:26a151d2c6db 36 signalStrength = 0;
oprospero 0:26a151d2c6db 37 xbeeRx.attach( this, &com::callback ); // Set callback as the interrupt handler.
oprospero 1:4f53de75bc96 38 #ifdef DEBUG
oprospero 0:26a151d2c6db 39 xbeeTx.printf("Communication.....Done\n\r");
oprospero 1:4f53de75bc96 40 #endif
oprospero 0:26a151d2c6db 41 }
oprospero 0:26a151d2c6db 42
oprospero 0:26a151d2c6db 43 /************************* bool isData() ********************************/
oprospero 0:26a151d2c6db 44 /* */
oprospero 0:26a151d2c6db 45 /*************************************************************************/
oprospero 0:26a151d2c6db 46
oprospero 0:26a151d2c6db 47 bool com::isData()
oprospero 0:26a151d2c6db 48 {
oprospero 2:bd1621102cad 49
oprospero 12:bf4642578682 50 return rdy2build;
oprospero 0:26a151d2c6db 51 }
oprospero 0:26a151d2c6db 52
oprospero 0:26a151d2c6db 53 /************************ void write( char ) *****************************/
oprospero 0:26a151d2c6db 54 /* Write a packet out the xbee com port. */
oprospero 0:26a151d2c6db 55 /* */
oprospero 0:26a151d2c6db 56 /* Data format byte[] */
oprospero 0:26a151d2c6db 57 /* byte[0] = command. */
oprospero 0:26a151d2c6db 58 /* byte[1] = upper 8 bits of value. */
oprospero 0:26a151d2c6db 59 /* byte[2] = lower 8 bits of value. */
oprospero 0:26a151d2c6db 60 /* byte[3] = Checksum byte[0] + byte[2]. */
oprospero 0:26a151d2c6db 61 /* byte[4] = Sequence Number. */
oprospero 0:26a151d2c6db 62 /* byte[5] = 255 End of message. */
oprospero 0:26a151d2c6db 63 /*************************************************************************/
oprospero 0:26a151d2c6db 64
oprospero 0:26a151d2c6db 65 void com::write( short command, short value )
oprospero 12:bf4642578682 66 {
oprospero 12:bf4642578682 67 short lvalue = (value % 128);
oprospero 12:bf4642578682 68 xbeeTx.putc( (char)command ); // Command
oprospero 12:bf4642578682 69 xbeeTx.putc( (char) value / 128 ); // First 8 bits in array.
oprospero 12:bf4642578682 70 xbeeTx.putc( (char) lvalue); // Second 8 bits in array.
oprospero 12:bf4642578682 71 xbeeTx.putc( command + lvalue ); // Checksum array[0] + array[1].
oprospero 12:bf4642578682 72 xbeeTx.putc( (char)value ); // Sequence number.
oprospero 12:bf4642578682 73 xbeeTx.putc( 255 ); // End of message.
oprospero 0:26a151d2c6db 74 }
oprospero 0:26a151d2c6db 75
oprospero 5:7cdf299ea7a4 76 /*************************** char ackCheck() ********************************/
oprospero 0:26a151d2c6db 77 /* */
oprospero 0:26a151d2c6db 78 /*************************************************************************/
oprospero 0:26a151d2c6db 79
oprospero 4:f8e953201251 80 void com::ackCheck()
oprospero 4:f8e953201251 81 {
oprospero 5:7cdf299ea7a4 82 if( !txBuffer->isEmpty() && xbeeTx.writeable())
oprospero 4:f8e953201251 83 {
oprospero 11:d1f488302d06 84 __disable_irq();
oprospero 5:7cdf299ea7a4 85 short * pkt = txBuffer->pop();
oprospero 5:7cdf299ea7a4 86 write(pkt[0],pkt[1]); //may need to disable interrupt
oprospero 5:7cdf299ea7a4 87 delete[] pkt;
oprospero 11:d1f488302d06 88 __enable_irq();
oprospero 4:f8e953201251 89 }
oprospero 4:f8e953201251 90 }
oprospero 4:f8e953201251 91
oprospero 5:7cdf299ea7a4 92 bool com::rdy2ack()
oprospero 5:7cdf299ea7a4 93 {
oprospero 5:7cdf299ea7a4 94 return !txBuffer->isEmpty();
oprospero 5:7cdf299ea7a4 95 }
oprospero 4:f8e953201251 96
oprospero 4:f8e953201251 97
oprospero 0:26a151d2c6db 98
oprospero 0:26a151d2c6db 99 /************************ void callback() ********************************/
oprospero 0:26a151d2c6db 100 /* */
oprospero 0:26a151d2c6db 101 /*************************************************************************/
oprospero 0:26a151d2c6db 102
oprospero 0:26a151d2c6db 103 void com::callback()
oprospero 0:26a151d2c6db 104 {
oprospero 4:f8e953201251 105 __disable_irq();
oprospero 0:26a151d2c6db 106 while( xbeeRx.readable() )
oprospero 0:26a151d2c6db 107 {
oprospero 0:26a151d2c6db 108 char data = xbeeRx.getc();
oprospero 12:bf4642578682 109
oprospero 12:bf4642578682 110 if (isA1)
oprospero 12:bf4642578682 111 {
oprospero 12:bf4642578682 112 if ( data == 255 && index1 > 4 )
oprospero 12:bf4642578682 113 {
oprospero 12:bf4642578682 114 rdy2build = true;
oprospero 12:bf4642578682 115 pindex = index1;
oprospero 12:bf4642578682 116 index1 = 0;
oprospero 12:bf4642578682 117 isA1 = false;
oprospero 12:bf4642578682 118 }
oprospero 12:bf4642578682 119 else if ( index1 < BUFFERSIZE )
oprospero 12:bf4642578682 120 {
oprospero 12:bf4642578682 121 buffer1[index1++] = data;
oprospero 12:bf4642578682 122 }
oprospero 12:bf4642578682 123 }
oprospero 12:bf4642578682 124 else
oprospero 12:bf4642578682 125 {
oprospero 12:bf4642578682 126 if ( data == 255 && index2 > 4 )
oprospero 12:bf4642578682 127 {
oprospero 12:bf4642578682 128 rdy2build = true;
oprospero 12:bf4642578682 129 pindex = index2;
oprospero 12:bf4642578682 130 index2 = 0;
oprospero 12:bf4642578682 131 isA1 = true;
oprospero 12:bf4642578682 132 }
oprospero 12:bf4642578682 133 else if ( index2 < BUFFERSIZE )
oprospero 12:bf4642578682 134 {
oprospero 12:bf4642578682 135 buffer2[index2++] = data;
oprospero 12:bf4642578682 136 }
oprospero 12:bf4642578682 137 }
oprospero 0:26a151d2c6db 138 }
oprospero 4:f8e953201251 139 __enable_irq();
oprospero 0:26a151d2c6db 140 }
oprospero 0:26a151d2c6db 141
oprospero 2:bd1621102cad 142
oprospero 0:26a151d2c6db 143 /********************** void packetBuilder() *****************************/
oprospero 0:26a151d2c6db 144 /* Creates a packet from the buffered data and places it in the rxBuffer */
oprospero 0:26a151d2c6db 145 /* queue to be read whenever convenient. Max value of +/- 8063. */
oprospero 0:26a151d2c6db 146 /*************************************************************************/
oprospero 0:26a151d2c6db 147
oprospero 12:bf4642578682 148 short * com::read()
oprospero 0:26a151d2c6db 149 {
oprospero 12:bf4642578682 150 if (rdy2build)
oprospero 0:26a151d2c6db 151 {
oprospero 12:bf4642578682 152 char * commandData = new char[pindex];
oprospero 12:bf4642578682 153 if (!isA1)
oprospero 12:bf4642578682 154 {
oprospero 12:bf4642578682 155 commandData[4] = buffer1[--pindex]; // Sequence Number.
oprospero 12:bf4642578682 156 commandData[3] = buffer1[--pindex]; // CheckSum value.
oprospero 12:bf4642578682 157 commandData[2] = buffer1[--pindex]; // Second 7 bits.
oprospero 12:bf4642578682 158 commandData[1] = buffer1[--pindex]; // Fisrt 7 bits.
oprospero 12:bf4642578682 159 commandData[0] = buffer1[--pindex]; // Command.
oprospero 12:bf4642578682 160 }
oprospero 12:bf4642578682 161 else
oprospero 12:bf4642578682 162 {
oprospero 12:bf4642578682 163 commandData[4] = buffer2[--pindex]; // Sequence Number.
oprospero 12:bf4642578682 164 commandData[3] = buffer2[--pindex]; // CheckSum value.
oprospero 12:bf4642578682 165 commandData[2] = buffer2[--pindex]; // Second 7 bits.
oprospero 12:bf4642578682 166 commandData[1] = buffer2[--pindex]; // Fisrt 7 bits.
oprospero 12:bf4642578682 167 commandData[0] = buffer2[--pindex]; // Command.
oprospero 12:bf4642578682 168 }
oprospero 0:26a151d2c6db 169
oprospero 12:bf4642578682 170
oprospero 12:bf4642578682 171 if( commandData[0] + commandData[2] == commandData[3] ) // Validate checksum.
oprospero 4:f8e953201251 172 {
oprospero 12:bf4642578682 173 short * array = new short[2];
oprospero 12:bf4642578682 174 array[0] = (short)commandData[0];
oprospero 12:bf4642578682 175
oprospero 12:bf4642578682 176 short value = (short)(commandData[1] * 128 + commandData[2]);
oprospero 12:bf4642578682 177
oprospero 12:bf4642578682 178 if( value > 8062 )
oprospero 12:bf4642578682 179 value = (short)value + 57344;
oprospero 12:bf4642578682 180
oprospero 12:bf4642578682 181 array[1] = value;
oprospero 12:bf4642578682 182 if ( commandData[0] != 0)
oprospero 12:bf4642578682 183 {
oprospero 12:bf4642578682 184 short * ackPacket = new short[2];
oprospero 12:bf4642578682 185 ackPacket[0] = commandData[0];
oprospero 12:bf4642578682 186 ackPacket[1] = commandData[4];
oprospero 12:bf4642578682 187 txBuffer->add( ackPacket ); // Ack the packet with sequence nuber.
oprospero 12:bf4642578682 188 }
oprospero 12:bf4642578682 189
oprospero 12:bf4642578682 190 delete[] commandData;
oprospero 12:bf4642578682 191 return array;
oprospero 12:bf4642578682 192 }
oprospero 12:bf4642578682 193 delete[] commandData;
oprospero 12:bf4642578682 194 }
oprospero 12:bf4642578682 195 return NULL;
oprospero 0:26a151d2c6db 196 }
oprospero 12:bf4642578682 197
oprospero 0:26a151d2c6db 198
oprospero 0:26a151d2c6db 199
oprospero 0:26a151d2c6db 200 /********************** bool isSignalGood() ******************************/
oprospero 0:26a151d2c6db 201 /* For future use */
oprospero 0:26a151d2c6db 202 /*************************************************************************/
oprospero 0:26a151d2c6db 203 bool com::isSignalGood()
oprospero 0:26a151d2c6db 204 {
oprospero 0:26a151d2c6db 205 signalStrength = rssi.dutycycle();
oprospero 0:26a151d2c6db 206 if (signalStrength > RSSI_THRES) return true;
oprospero 0:26a151d2c6db 207 else return false;
oprospero 0:26a151d2c6db 208 }