Prosper Van / xbeeCom

xbee communication for UWB quadcopter project Originally by Greg Abdo Forking to reduce impact of interrupt by moving packetbuilder out of the interrupt and letting be handled in the main loop

Fork of com by Prosper Van

com.cpp@13:2fb7b19dcd70, 2014-05-22 (annotated)

Committer:
oprospero
Date:
Thu May 22 05:58:40 2014 +0000
Revision:
13:2fb7b19dcd70
Parent:
12:bf4642578682
Child:
14:d2acb373d81c
fixed random burst hopefully and improved packet drops

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 "com.h"
oprospero 13:2fb7b19dcd70 20 #ifdef DEBUG_COM
oprospero 13:2fb7b19dcd70 21 Timer timerCom;
oprospero 13:2fb7b19dcd70 22 #define NL "\n\r"
oprospero 13:2fb7b19dcd70 23 #define PRINT(x) xbeeTx.printf(x) //Serial.print(x)
oprospero 13:2fb7b19dcd70 24 #define PRINTF(x, y) xbeeTx.printf( (x) ,(y) ) //Serial.print(x, y)
oprospero 13:2fb7b19dcd70 25 #define PRINTLN(x) PRINT(x);PRINT(NL)
oprospero 13:2fb7b19dcd70 26 #define PRINTLNF(x, y) PRINTF((x) ,(y));PRINT(NL)
oprospero 13:2fb7b19dcd70 27 #define START timerCom.start();
oprospero 13:2fb7b19dcd70 28 #define STOP timerCom.stop()
oprospero 13:2fb7b19dcd70 29 #define RESET timerCom.reset()
oprospero 13:2fb7b19dcd70 30 #define READ timerCom.read_us()
oprospero 13:2fb7b19dcd70 31 #define GET(x) x = READ
oprospero 13:2fb7b19dcd70 32 #else
oprospero 13:2fb7b19dcd70 33 #define PRINT(x)
oprospero 13:2fb7b19dcd70 34 #define PRINTF(x, y)
oprospero 13:2fb7b19dcd70 35 #define PRINTLN(x)
oprospero 13:2fb7b19dcd70 36 #define PRINTLNF(x, y)
oprospero 13:2fb7b19dcd70 37 #define START
oprospero 13:2fb7b19dcd70 38 #define STOP
oprospero 13:2fb7b19dcd70 39 #define RESET
oprospero 13:2fb7b19dcd70 40 #define READ
oprospero 13:2fb7b19dcd70 41 #define GET(x)
oprospero 13:2fb7b19dcd70 42 #endif
oprospero 0:26a151d2c6db 43
oprospero 1:4f53de75bc96 44
oprospero 0:26a151d2c6db 45 /*********************** com( PinName, PinName ) *************************/
oprospero 0:26a151d2c6db 46 /* */
oprospero 0:26a151d2c6db 47 /*************************************************************************/
oprospero 0:26a151d2c6db 48
oprospero 2:bd1621102cad 49 com::com( PinName tx, PinName rx , PinName rssipin) : xbeeTx( tx, NC), xbeeRx( NC, rx), rssi(rssipin)
oprospero 0:26a151d2c6db 50 {
oprospero 13:2fb7b19dcd70 51 index1 = 0; // How many bytes are in the buffer.
oprospero 13:2fb7b19dcd70 52 index2 = 0; // How many bytes are in the buffer.
oprospero 13:2fb7b19dcd70 53 pindex = 0; // How many bytes are in the buffer.
oprospero 13:2fb7b19dcd70 54 rdy2build = false; // Xbee is in transparent mode.
oprospero 13:2fb7b19dcd70 55 xbeeTx.baud(BAUDRATE); // Setup the serial baud rate.
oprospero 13:2fb7b19dcd70 56 xbeeRx.baud(BAUDRATE); // Setup the serial baud rate.
oprospero 5:7cdf299ea7a4 57 txBuffer = new queue();
oprospero 0:26a151d2c6db 58 signalStrength = 0;
oprospero 0:26a151d2c6db 59 xbeeRx.attach( this, &com::callback ); // Set callback as the interrupt handler.
oprospero 13:2fb7b19dcd70 60 #ifdef DEBUG_COM
oprospero 0:26a151d2c6db 61 xbeeTx.printf("Communication.....Done\n\r");
oprospero 1:4f53de75bc96 62 #endif
oprospero 13:2fb7b19dcd70 63 START;
oprospero 0:26a151d2c6db 64 }
oprospero 0:26a151d2c6db 65
oprospero 0:26a151d2c6db 66 /************************* bool isData() ********************************/
oprospero 0:26a151d2c6db 67 /* */
oprospero 0:26a151d2c6db 68 /*************************************************************************/
oprospero 0:26a151d2c6db 69
oprospero 0:26a151d2c6db 70 bool com::isData()
oprospero 0:26a151d2c6db 71 {
oprospero 12:bf4642578682 72 return rdy2build;
oprospero 0:26a151d2c6db 73 }
oprospero 0:26a151d2c6db 74
oprospero 0:26a151d2c6db 75 /************************ void write( char ) *****************************/
oprospero 0:26a151d2c6db 76 /* Write a packet out the xbee com port. */
oprospero 0:26a151d2c6db 77 /* */
oprospero 0:26a151d2c6db 78 /* Data format byte[] */
oprospero 0:26a151d2c6db 79 /* byte[0] = command. */
oprospero 0:26a151d2c6db 80 /* byte[1] = upper 8 bits of value. */
oprospero 0:26a151d2c6db 81 /* byte[2] = lower 8 bits of value. */
oprospero 0:26a151d2c6db 82 /* byte[3] = Checksum byte[0] + byte[2]. */
oprospero 0:26a151d2c6db 83 /* byte[4] = Sequence Number. */
oprospero 0:26a151d2c6db 84 /* byte[5] = 255 End of message. */
oprospero 0:26a151d2c6db 85 /*************************************************************************/
oprospero 0:26a151d2c6db 86
oprospero 0:26a151d2c6db 87 void com::write( short command, short value )
oprospero 12:bf4642578682 88 {
oprospero 12:bf4642578682 89 short lvalue = (value % 128);
oprospero 12:bf4642578682 90 xbeeTx.putc( (char)command ); // Command
oprospero 12:bf4642578682 91 xbeeTx.putc( (char) value / 128 ); // First 8 bits in array.
oprospero 12:bf4642578682 92 xbeeTx.putc( (char) lvalue); // Second 8 bits in array.
oprospero 12:bf4642578682 93 xbeeTx.putc( command + lvalue ); // Checksum array[0] + array[1].
oprospero 12:bf4642578682 94 xbeeTx.putc( (char)value ); // Sequence number.
oprospero 12:bf4642578682 95 xbeeTx.putc( 255 ); // End of message.
oprospero 0:26a151d2c6db 96 }
oprospero 0:26a151d2c6db 97
oprospero 5:7cdf299ea7a4 98 /*************************** char ackCheck() ********************************/
oprospero 0:26a151d2c6db 99 /* */
oprospero 0:26a151d2c6db 100 /*************************************************************************/
oprospero 0:26a151d2c6db 101
oprospero 4:f8e953201251 102 void com::ackCheck()
oprospero 4:f8e953201251 103 {
oprospero 13:2fb7b19dcd70 104 if( !txBuffer->isEmpty())
oprospero 4:f8e953201251 105 {
oprospero 11:d1f488302d06 106 __disable_irq();
oprospero 5:7cdf299ea7a4 107 short * pkt = txBuffer->pop();
oprospero 13:2fb7b19dcd70 108 __enable_irq();
oprospero 5:7cdf299ea7a4 109 write(pkt[0],pkt[1]); //may need to disable interrupt
oprospero 13:2fb7b19dcd70 110 #ifdef DEBUG_COM
oprospero 13:2fb7b19dcd70 111 if(pkt[1] % 5 == 0)
oprospero 13:2fb7b19dcd70 112 {
oprospero 13:2fb7b19dcd70 113 PRINTLNF("len: %d",txBuffer->queueLength());
oprospero 13:2fb7b19dcd70 114 }
oprospero 13:2fb7b19dcd70 115 #endif
oprospero 5:7cdf299ea7a4 116 delete[] pkt;
oprospero 13:2fb7b19dcd70 117
oprospero 4:f8e953201251 118 }
oprospero 4:f8e953201251 119 }
oprospero 4:f8e953201251 120
oprospero 5:7cdf299ea7a4 121 bool com::rdy2ack()
oprospero 5:7cdf299ea7a4 122 {
oprospero 5:7cdf299ea7a4 123 return !txBuffer->isEmpty();
oprospero 5:7cdf299ea7a4 124 }
oprospero 4:f8e953201251 125
oprospero 4:f8e953201251 126
oprospero 0:26a151d2c6db 127
oprospero 0:26a151d2c6db 128 /************************ void callback() ********************************/
oprospero 0:26a151d2c6db 129 /* */
oprospero 0:26a151d2c6db 130 /*************************************************************************/
oprospero 0:26a151d2c6db 131
oprospero 0:26a151d2c6db 132 void com::callback()
oprospero 0:26a151d2c6db 133 {
oprospero 4:f8e953201251 134 __disable_irq();
oprospero 0:26a151d2c6db 135 while( xbeeRx.readable() )
oprospero 0:26a151d2c6db 136 {
oprospero 0:26a151d2c6db 137 char data = xbeeRx.getc();
oprospero 13:2fb7b19dcd70 138 // xbeeRx.putc(data);
oprospero 12:bf4642578682 139 if (isA1)
oprospero 12:bf4642578682 140 {
oprospero 12:bf4642578682 141 if ( data == 255 && index1 > 4 )
oprospero 12:bf4642578682 142 {
oprospero 12:bf4642578682 143 rdy2build = true;
oprospero 12:bf4642578682 144 pindex = index1;
oprospero 12:bf4642578682 145 index1 = 0;
oprospero 12:bf4642578682 146 isA1 = false;
oprospero 12:bf4642578682 147 }
oprospero 12:bf4642578682 148 else if ( index1 < BUFFERSIZE )
oprospero 12:bf4642578682 149 {
oprospero 13:2fb7b19dcd70 150
oprospero 12:bf4642578682 151 buffer1[index1++] = data;
oprospero 12:bf4642578682 152 }
oprospero 12:bf4642578682 153 }
oprospero 12:bf4642578682 154 else
oprospero 12:bf4642578682 155 {
oprospero 12:bf4642578682 156 if ( data == 255 && index2 > 4 )
oprospero 12:bf4642578682 157 {
oprospero 12:bf4642578682 158 rdy2build = true;
oprospero 12:bf4642578682 159 pindex = index2;
oprospero 12:bf4642578682 160 index2 = 0;
oprospero 12:bf4642578682 161 isA1 = true;
oprospero 12:bf4642578682 162 }
oprospero 12:bf4642578682 163 else if ( index2 < BUFFERSIZE )
oprospero 12:bf4642578682 164 {
oprospero 12:bf4642578682 165 buffer2[index2++] = data;
oprospero 12:bf4642578682 166 }
oprospero 12:bf4642578682 167 }
oprospero 0:26a151d2c6db 168 }
oprospero 4:f8e953201251 169 __enable_irq();
oprospero 0:26a151d2c6db 170 }
oprospero 0:26a151d2c6db 171
oprospero 2:bd1621102cad 172
oprospero 0:26a151d2c6db 173 /********************** void packetBuilder() *****************************/
oprospero 0:26a151d2c6db 174 /* Creates a packet from the buffered data and places it in the rxBuffer */
oprospero 0:26a151d2c6db 175 /* queue to be read whenever convenient. Max value of +/- 8063. */
oprospero 0:26a151d2c6db 176 /*************************************************************************/
oprospero 0:26a151d2c6db 177
oprospero 12:bf4642578682 178 short * com::read()
oprospero 0:26a151d2c6db 179 {
oprospero 12:bf4642578682 180 if (rdy2build)
oprospero 0:26a151d2c6db 181 {
oprospero 13:2fb7b19dcd70 182 rdy2build = false;
oprospero 13:2fb7b19dcd70 183 char * commandData = new char[5];
oprospero 12:bf4642578682 184 if (!isA1)
oprospero 12:bf4642578682 185 {
oprospero 12:bf4642578682 186 commandData[4] = buffer1[--pindex]; // Sequence Number.
oprospero 12:bf4642578682 187 commandData[3] = buffer1[--pindex]; // CheckSum value.
oprospero 12:bf4642578682 188 commandData[2] = buffer1[--pindex]; // Second 7 bits.
oprospero 12:bf4642578682 189 commandData[1] = buffer1[--pindex]; // Fisrt 7 bits.
oprospero 12:bf4642578682 190 commandData[0] = buffer1[--pindex]; // Command.
oprospero 12:bf4642578682 191 }
oprospero 12:bf4642578682 192 else
oprospero 12:bf4642578682 193 {
oprospero 12:bf4642578682 194 commandData[4] = buffer2[--pindex]; // Sequence Number.
oprospero 12:bf4642578682 195 commandData[3] = buffer2[--pindex]; // CheckSum value.
oprospero 12:bf4642578682 196 commandData[2] = buffer2[--pindex]; // Second 7 bits.
oprospero 12:bf4642578682 197 commandData[1] = buffer2[--pindex]; // Fisrt 7 bits.
oprospero 12:bf4642578682 198 commandData[0] = buffer2[--pindex]; // Command.
oprospero 12:bf4642578682 199 }
oprospero 0:26a151d2c6db 200
oprospero 13:2fb7b19dcd70 201 // xbeeTx.printf("Copied: %d %d %d %d %d\n\r",commandData[0],commandData[1],commandData[2],commandData[3],commandData[4]);
oprospero 12:bf4642578682 202
oprospero 12:bf4642578682 203 if( commandData[0] + commandData[2] == commandData[3] ) // Validate checksum.
oprospero 4:f8e953201251 204 {
oprospero 12:bf4642578682 205 short * array = new short[2];
oprospero 12:bf4642578682 206 array[0] = (short)commandData[0];
oprospero 12:bf4642578682 207
oprospero 12:bf4642578682 208 short value = (short)(commandData[1] * 128 + commandData[2]);
oprospero 12:bf4642578682 209
oprospero 12:bf4642578682 210 if( value > 8062 )
oprospero 12:bf4642578682 211 value = (short)value + 57344;
oprospero 12:bf4642578682 212
oprospero 12:bf4642578682 213 array[1] = value;
oprospero 12:bf4642578682 214 if ( commandData[0] != 0)
oprospero 12:bf4642578682 215 {
oprospero 12:bf4642578682 216 short * ackPacket = new short[2];
oprospero 12:bf4642578682 217 ackPacket[0] = commandData[0];
oprospero 12:bf4642578682 218 ackPacket[1] = commandData[4];
oprospero 12:bf4642578682 219 txBuffer->add( ackPacket ); // Ack the packet with sequence nuber.
oprospero 12:bf4642578682 220 }
oprospero 12:bf4642578682 221
oprospero 12:bf4642578682 222 delete[] commandData;
oprospero 12:bf4642578682 223 return array;
oprospero 12:bf4642578682 224 }
oprospero 12:bf4642578682 225 delete[] commandData;
oprospero 12:bf4642578682 226 }
oprospero 12:bf4642578682 227 return NULL;
oprospero 0:26a151d2c6db 228 }
oprospero 12:bf4642578682 229
oprospero 0:26a151d2c6db 230
oprospero 0:26a151d2c6db 231
oprospero 0:26a151d2c6db 232 /********************** bool isSignalGood() ******************************/
oprospero 0:26a151d2c6db 233 /* For future use */
oprospero 0:26a151d2c6db 234 /*************************************************************************/
oprospero 0:26a151d2c6db 235 bool com::isSignalGood()
oprospero 0:26a151d2c6db 236 {
oprospero 0:26a151d2c6db 237 signalStrength = rssi.dutycycle();
oprospero 0:26a151d2c6db 238 if (signalStrength > RSSI_THRES) return true;
oprospero 0:26a151d2c6db 239 else return false;
oprospero 0:26a151d2c6db 240 }