Transmitter code for quadcopter

Dependencies:   mbed

Committer:
madcowswe
Date:
Tue Nov 22 23:20:34 2011 +0000
Revision:
0:1b2cbe8cabf1

        

Who changed what in which revision?

UserRevisionLine numberNew contents of line
madcowswe 0:1b2cbe8cabf1 1 #include "RF12B.h"
madcowswe 0:1b2cbe8cabf1 2
madcowswe 0:1b2cbe8cabf1 3 #include "RF_defs.h"
madcowswe 0:1b2cbe8cabf1 4 #include <algorithm>
madcowswe 0:1b2cbe8cabf1 5
madcowswe 0:1b2cbe8cabf1 6 RF12B::RF12B(PinName _SDI,
madcowswe 0:1b2cbe8cabf1 7 PinName _SDO,
madcowswe 0:1b2cbe8cabf1 8 PinName _SCK,
madcowswe 0:1b2cbe8cabf1 9 PinName _NCS,
madcowswe 0:1b2cbe8cabf1 10 PinName _NIRQ):spi(_SDI, _SDO, _SCK),
madcowswe 0:1b2cbe8cabf1 11 NCS(_NCS), NIRQ(_NIRQ), NIRQ_in(_NIRQ), rfled(LED3) {
madcowswe 0:1b2cbe8cabf1 12
madcowswe 0:1b2cbe8cabf1 13 /* SPI frequency, word lenght, polarity and phase */
madcowswe 0:1b2cbe8cabf1 14 spi.format(16,0);
madcowswe 0:1b2cbe8cabf1 15 spi.frequency(2000000);
madcowswe 0:1b2cbe8cabf1 16
madcowswe 0:1b2cbe8cabf1 17 /* Set ~CS high */
madcowswe 0:1b2cbe8cabf1 18 NCS = 1;
madcowswe 0:1b2cbe8cabf1 19
madcowswe 0:1b2cbe8cabf1 20 /* Initialise RF Module */
madcowswe 0:1b2cbe8cabf1 21 init();
madcowswe 0:1b2cbe8cabf1 22
madcowswe 0:1b2cbe8cabf1 23 /* Setup interrupt to happen on falling edge of NIRQ */
madcowswe 0:1b2cbe8cabf1 24 NIRQ.fall(this, &RF12B::rxISR);
madcowswe 0:1b2cbe8cabf1 25 }
madcowswe 0:1b2cbe8cabf1 26
madcowswe 0:1b2cbe8cabf1 27 /* Returns the packet length if data is available in the receive buffer, 0 otherwise*/
madcowswe 0:1b2cbe8cabf1 28 unsigned int RF12B::available() {
madcowswe 0:1b2cbe8cabf1 29 return fifo.size();
madcowswe 0:1b2cbe8cabf1 30 }
madcowswe 0:1b2cbe8cabf1 31
madcowswe 0:1b2cbe8cabf1 32 /* Reads a packet of data, with length "size" Returns false if read failed. TODO: make a metafifo to isolate packets*/
madcowswe 0:1b2cbe8cabf1 33 bool RF12B::read(unsigned char* data, unsigned int size) {
madcowswe 0:1b2cbe8cabf1 34 if (fifo.size() == 0) {
madcowswe 0:1b2cbe8cabf1 35 return false;
madcowswe 0:1b2cbe8cabf1 36 } else {
madcowswe 0:1b2cbe8cabf1 37 unsigned int i = 0;
madcowswe 0:1b2cbe8cabf1 38 while (fifo.size() > 0 && i < size) {
madcowswe 0:1b2cbe8cabf1 39 data[i++] = fifo.front();
madcowswe 0:1b2cbe8cabf1 40 fifo.pop();
madcowswe 0:1b2cbe8cabf1 41 }
madcowswe 0:1b2cbe8cabf1 42 return true;
madcowswe 0:1b2cbe8cabf1 43 }
madcowswe 0:1b2cbe8cabf1 44 }
madcowswe 0:1b2cbe8cabf1 45
madcowswe 0:1b2cbe8cabf1 46 /* Reads a byte of data from the receive buffer */
madcowswe 0:1b2cbe8cabf1 47 unsigned char RF12B::read() {
madcowswe 0:1b2cbe8cabf1 48 if (available()) {
madcowswe 0:1b2cbe8cabf1 49 unsigned char data = fifo.front();
madcowswe 0:1b2cbe8cabf1 50 fifo.pop();
madcowswe 0:1b2cbe8cabf1 51 return data;
madcowswe 0:1b2cbe8cabf1 52 } else {
madcowswe 0:1b2cbe8cabf1 53 return 0xFF; // Error val although could also be data...
madcowswe 0:1b2cbe8cabf1 54 }
madcowswe 0:1b2cbe8cabf1 55 }
madcowswe 0:1b2cbe8cabf1 56
madcowswe 0:1b2cbe8cabf1 57 /* Sends a packet of data to the RF module for transmission TODO: Make asych*/
madcowswe 0:1b2cbe8cabf1 58 void RF12B::write(unsigned char *data, unsigned char length) {
madcowswe 0:1b2cbe8cabf1 59 unsigned char crc = 0;
madcowswe 0:1b2cbe8cabf1 60
madcowswe 0:1b2cbe8cabf1 61 /* Transmitter mode */
madcowswe 0:1b2cbe8cabf1 62 changeMode(TX);
madcowswe 0:1b2cbe8cabf1 63
madcowswe 0:1b2cbe8cabf1 64 writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 65 send(0xAA); // PREAMBLE
madcowswe 0:1b2cbe8cabf1 66 send(0xAA);
madcowswe 0:1b2cbe8cabf1 67 send(0xAA);
madcowswe 0:1b2cbe8cabf1 68 send(0x2D); // SYNC
madcowswe 0:1b2cbe8cabf1 69 send(0xD4);
madcowswe 0:1b2cbe8cabf1 70 /* Packet Length */
madcowswe 0:1b2cbe8cabf1 71 send(length);
madcowswe 0:1b2cbe8cabf1 72 crc = crc8(crc, length);
madcowswe 0:1b2cbe8cabf1 73 send(crc);
madcowswe 0:1b2cbe8cabf1 74 crc = crc8(crc, crc);
madcowswe 0:1b2cbe8cabf1 75 /* Packet Data */
madcowswe 0:1b2cbe8cabf1 76 for (unsigned char i=0; i<length; i++) {
madcowswe 0:1b2cbe8cabf1 77 send(data[i]);
madcowswe 0:1b2cbe8cabf1 78 crc = crc8(crc, data[i]);
madcowswe 0:1b2cbe8cabf1 79 }
madcowswe 0:1b2cbe8cabf1 80 send(crc);
madcowswe 0:1b2cbe8cabf1 81 send(0xAA); // DUMMY BYTES
madcowswe 0:1b2cbe8cabf1 82 send(0xAA);
madcowswe 0:1b2cbe8cabf1 83 send(0xAA);
madcowswe 0:1b2cbe8cabf1 84
madcowswe 0:1b2cbe8cabf1 85 /* Back to receiver mode */
madcowswe 0:1b2cbe8cabf1 86 changeMode(RX);
madcowswe 0:1b2cbe8cabf1 87 status();
madcowswe 0:1b2cbe8cabf1 88 }
madcowswe 0:1b2cbe8cabf1 89
madcowswe 0:1b2cbe8cabf1 90 /* Transmit a 1-byte data packet */
madcowswe 0:1b2cbe8cabf1 91 void RF12B::write(unsigned char data) {
madcowswe 0:1b2cbe8cabf1 92 write(&data, 1);
madcowswe 0:1b2cbe8cabf1 93 }
madcowswe 0:1b2cbe8cabf1 94
madcowswe 0:1b2cbe8cabf1 95 void RF12B::write(queue<char> &data, int length) {
madcowswe 0:1b2cbe8cabf1 96 char crc = 0;
madcowswe 0:1b2cbe8cabf1 97 char length_byte = 0;
madcowswe 0:1b2cbe8cabf1 98
madcowswe 0:1b2cbe8cabf1 99 /* -1 means try to transmit everything in the queue */
madcowswe 0:1b2cbe8cabf1 100 if(length == -1) {
madcowswe 0:1b2cbe8cabf1 101 length = data.size();
madcowswe 0:1b2cbe8cabf1 102 }
madcowswe 0:1b2cbe8cabf1 103
madcowswe 0:1b2cbe8cabf1 104 /* max length of packet is 255 */
madcowswe 0:1b2cbe8cabf1 105 length_byte = min(length, 255);
madcowswe 0:1b2cbe8cabf1 106
madcowswe 0:1b2cbe8cabf1 107 /* Transmitter mode */
madcowswe 0:1b2cbe8cabf1 108 changeMode(TX);
madcowswe 0:1b2cbe8cabf1 109
madcowswe 0:1b2cbe8cabf1 110 writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 111 send(0xAA); // PREAMBLE
madcowswe 0:1b2cbe8cabf1 112 send(0xAA);
madcowswe 0:1b2cbe8cabf1 113 send(0xAA);
madcowswe 0:1b2cbe8cabf1 114 send(0x2D); // SYNC
madcowswe 0:1b2cbe8cabf1 115 send(0xD4);
madcowswe 0:1b2cbe8cabf1 116 /* Packet Length */
madcowswe 0:1b2cbe8cabf1 117 send(length_byte);
madcowswe 0:1b2cbe8cabf1 118 crc = crc8(crc, length_byte);
madcowswe 0:1b2cbe8cabf1 119 send(crc);
madcowswe 0:1b2cbe8cabf1 120 crc = crc8(crc, crc);
madcowswe 0:1b2cbe8cabf1 121 /* Packet Data */
madcowswe 0:1b2cbe8cabf1 122 for (char i=0; i<length_byte; i++) {
madcowswe 0:1b2cbe8cabf1 123 send(data.front());
madcowswe 0:1b2cbe8cabf1 124 crc = crc8(crc, data.front());
madcowswe 0:1b2cbe8cabf1 125 data.pop();
madcowswe 0:1b2cbe8cabf1 126 }
madcowswe 0:1b2cbe8cabf1 127 send(crc);
madcowswe 0:1b2cbe8cabf1 128 send(0xAA); // DUMMY BYTES
madcowswe 0:1b2cbe8cabf1 129 send(0xAA);
madcowswe 0:1b2cbe8cabf1 130 send(0xAA);
madcowswe 0:1b2cbe8cabf1 131
madcowswe 0:1b2cbe8cabf1 132 /* Back to receiver mode */
madcowswe 0:1b2cbe8cabf1 133 changeMode(RX);
madcowswe 0:1b2cbe8cabf1 134 status();
madcowswe 0:1b2cbe8cabf1 135 }
madcowswe 0:1b2cbe8cabf1 136
madcowswe 0:1b2cbe8cabf1 137 /**********************************************************************
madcowswe 0:1b2cbe8cabf1 138 * PRIVATE FUNCTIONS
madcowswe 0:1b2cbe8cabf1 139 *********************************************************************/
madcowswe 0:1b2cbe8cabf1 140
madcowswe 0:1b2cbe8cabf1 141 /* Initialises the RF12B module */
madcowswe 0:1b2cbe8cabf1 142 void RF12B::init() {
madcowswe 0:1b2cbe8cabf1 143 /* writeCmd(0x80E7); //EL,EF,868band,12.0pF
madcowswe 0:1b2cbe8cabf1 144 changeMode(RX);
madcowswe 0:1b2cbe8cabf1 145 writeCmd(0xA640); //frequency select
madcowswe 0:1b2cbe8cabf1 146 writeCmd(0xC647); //4.8kbps
madcowswe 0:1b2cbe8cabf1 147 writeCmd(0x94A0); //VDI,FAST,134kHz,0dBm,-103dBm
madcowswe 0:1b2cbe8cabf1 148 writeCmd(0xC2AC); //AL,!ml,DIG,DQD4
madcowswe 0:1b2cbe8cabf1 149 writeCmd(0xCA81); //FIFO8,SYNC,!ff,DR
madcowswe 0:1b2cbe8cabf1 150 writeCmd(0xCED4); //SYNC=2DD4
madcowswe 0:1b2cbe8cabf1 151 writeCmd(0xC483); //@PWR,NO RSTRIC,!st,!fi,OE,EN
madcowswe 0:1b2cbe8cabf1 152 writeCmd(0x9850); //!mp,90kHz,MAX OUT
madcowswe 0:1b2cbe8cabf1 153 writeCmd(0xCC17); //OB1, COB0, LPX, Iddy, CDDIT&#65533;CBW0
madcowswe 0:1b2cbe8cabf1 154 writeCmd(0xE000); //NOT USED
madcowswe 0:1b2cbe8cabf1 155 writeCmd(0xC800); //NOT USED
madcowswe 0:1b2cbe8cabf1 156 writeCmd(0xC040); //1.66MHz,2.2V */
madcowswe 0:1b2cbe8cabf1 157
madcowswe 0:1b2cbe8cabf1 158 writeCmd(
madcowswe 0:1b2cbe8cabf1 159 RFM_CONFIG_EL |
madcowswe 0:1b2cbe8cabf1 160 RFM_CONFIG_EF |
madcowswe 0:1b2cbe8cabf1 161 RFM_CONFIG_BAND_433 //|
madcowswe 0:1b2cbe8cabf1 162 //RFM_CONFIG_X_11_0pf // meh, using default
madcowswe 0:1b2cbe8cabf1 163 );
madcowswe 0:1b2cbe8cabf1 164
madcowswe 0:1b2cbe8cabf1 165 // 2. Power Management Command
madcowswe 0:1b2cbe8cabf1 166 // leave everything switched off for now
madcowswe 0:1b2cbe8cabf1 167 /*
madcowswe 0:1b2cbe8cabf1 168 writeCmd(
madcowswe 0:1b2cbe8cabf1 169 RFM_POWER_MANAGEMENT // switch all off
madcowswe 0:1b2cbe8cabf1 170 );
madcowswe 0:1b2cbe8cabf1 171 */
madcowswe 0:1b2cbe8cabf1 172
madcowswe 0:1b2cbe8cabf1 173 // 3. Frequency Setting Command
madcowswe 0:1b2cbe8cabf1 174 writeCmd(
madcowswe 0:1b2cbe8cabf1 175 RFM_FREQUENCY |
madcowswe 0:1b2cbe8cabf1 176 RFM_FREQ_433Band(435.7) //I totally made this value up... if someone knows where the sweetspots are in this band, tell me!
madcowswe 0:1b2cbe8cabf1 177 );
madcowswe 0:1b2cbe8cabf1 178
madcowswe 0:1b2cbe8cabf1 179
madcowswe 0:1b2cbe8cabf1 180 // 4. Data Rate Command
madcowswe 0:1b2cbe8cabf1 181 writeCmd(RFM_DATA_RATE_9600);
madcowswe 0:1b2cbe8cabf1 182
madcowswe 0:1b2cbe8cabf1 183
madcowswe 0:1b2cbe8cabf1 184 // 5. Receiver Control Command
madcowswe 0:1b2cbe8cabf1 185 writeCmd(
madcowswe 0:1b2cbe8cabf1 186 RFM_RX_CONTROL_P20_VDI |
madcowswe 0:1b2cbe8cabf1 187 RFM_RX_CONTROL_VDI_FAST |
madcowswe 0:1b2cbe8cabf1 188 //RFM_RX_CONTROL_BW(RFM_BAUD_RATE) |
madcowswe 0:1b2cbe8cabf1 189 RFM_RX_CONTROL_BW_134 | // CHANGE THIS TO 67 TO IMPROVE RANGE! (though the bitrate must then be below 8kbaud, and fsk modulation changed)
madcowswe 0:1b2cbe8cabf1 190 RFM_RX_CONTROL_GAIN_0 |
madcowswe 0:1b2cbe8cabf1 191 RFM_RX_CONTROL_RSSI_103 // Might need adjustment. Datasheet says around 10^-5 bit error rate at this level and baudrate.
madcowswe 0:1b2cbe8cabf1 192 );
madcowswe 0:1b2cbe8cabf1 193
madcowswe 0:1b2cbe8cabf1 194 // 6. Data Filter Command
madcowswe 0:1b2cbe8cabf1 195 writeCmd(
madcowswe 0:1b2cbe8cabf1 196 RFM_DATA_FILTER_AL |
madcowswe 0:1b2cbe8cabf1 197 RFM_DATA_FILTER_ML |
madcowswe 0:1b2cbe8cabf1 198 RFM_DATA_FILTER_DIG //|
madcowswe 0:1b2cbe8cabf1 199 //RFM_DATA_FILTER_DQD(4)
madcowswe 0:1b2cbe8cabf1 200 );
madcowswe 0:1b2cbe8cabf1 201
madcowswe 0:1b2cbe8cabf1 202 // 7. FIFO and Reset Mode Command
madcowswe 0:1b2cbe8cabf1 203 writeCmd(
madcowswe 0:1b2cbe8cabf1 204 RFM_FIFO_IT(8) |
madcowswe 0:1b2cbe8cabf1 205 RFM_FIFO_DR |
madcowswe 0:1b2cbe8cabf1 206 0x8 //turn on 16bit sync word
madcowswe 0:1b2cbe8cabf1 207 );
madcowswe 0:1b2cbe8cabf1 208
madcowswe 0:1b2cbe8cabf1 209 // 8. FIFO Syncword
madcowswe 0:1b2cbe8cabf1 210 // Leave as default: 0xD4
madcowswe 0:1b2cbe8cabf1 211
madcowswe 0:1b2cbe8cabf1 212 // 9. Receiver FIFO Read
madcowswe 0:1b2cbe8cabf1 213 // when the interupt goes high, (and if we can assume that it was a fifo fill interrupt) we can read a byte using:
madcowswe 0:1b2cbe8cabf1 214 // result = RFM_READ_FIFO();
madcowswe 0:1b2cbe8cabf1 215
madcowswe 0:1b2cbe8cabf1 216 // 10. AFC Command
madcowswe 0:1b2cbe8cabf1 217 writeCmd(
madcowswe 0:1b2cbe8cabf1 218 //RFM_AFC_AUTO_VDI | //Note this might be changed to improve range. Refer to datasheet.
madcowswe 0:1b2cbe8cabf1 219 RFM_AFC_AUTO_INDEPENDENT |
madcowswe 0:1b2cbe8cabf1 220 RFM_AFC_RANGE_LIMIT_7_8 |
madcowswe 0:1b2cbe8cabf1 221 RFM_AFC_EN |
madcowswe 0:1b2cbe8cabf1 222 RFM_AFC_OE |
madcowswe 0:1b2cbe8cabf1 223 RFM_AFC_FI
madcowswe 0:1b2cbe8cabf1 224 );
madcowswe 0:1b2cbe8cabf1 225
madcowswe 0:1b2cbe8cabf1 226 // 11. TX Configuration Control Command
madcowswe 0:1b2cbe8cabf1 227 writeCmd(
madcowswe 0:1b2cbe8cabf1 228 RFM_TX_CONTROL_MOD_60 |
madcowswe 0:1b2cbe8cabf1 229 RFM_TX_CONTROL_POW_0
madcowswe 0:1b2cbe8cabf1 230 );
madcowswe 0:1b2cbe8cabf1 231
madcowswe 0:1b2cbe8cabf1 232
madcowswe 0:1b2cbe8cabf1 233 // 12. PLL Setting Command
madcowswe 0:1b2cbe8cabf1 234 writeCmd(
madcowswe 0:1b2cbe8cabf1 235 0xCC77 & ~0x01 // Setting the PLL bandwith, less noise, but max bitrate capped at 86.2
madcowswe 0:1b2cbe8cabf1 236 // I think this will slow down the pll's reaction time. Not sure, check with someone!
madcowswe 0:1b2cbe8cabf1 237 );
madcowswe 0:1b2cbe8cabf1 238
madcowswe 0:1b2cbe8cabf1 239 resetRX();
madcowswe 0:1b2cbe8cabf1 240 status();
madcowswe 0:1b2cbe8cabf1 241 }
madcowswe 0:1b2cbe8cabf1 242
madcowswe 0:1b2cbe8cabf1 243 /* Write a command to the RF Module */
madcowswe 0:1b2cbe8cabf1 244 unsigned int RF12B::writeCmd(unsigned int cmd) {
madcowswe 0:1b2cbe8cabf1 245 NCS = 0;
madcowswe 0:1b2cbe8cabf1 246 unsigned int recv = spi.write(cmd);
madcowswe 0:1b2cbe8cabf1 247 NCS = 1;
madcowswe 0:1b2cbe8cabf1 248 return recv;
madcowswe 0:1b2cbe8cabf1 249 }
madcowswe 0:1b2cbe8cabf1 250
madcowswe 0:1b2cbe8cabf1 251 /* Sends a byte of data across RF */
madcowswe 0:1b2cbe8cabf1 252 void RF12B::send(unsigned char data) {
madcowswe 0:1b2cbe8cabf1 253 while (NIRQ);
madcowswe 0:1b2cbe8cabf1 254 writeCmd(0xB800 + data);
madcowswe 0:1b2cbe8cabf1 255 }
madcowswe 0:1b2cbe8cabf1 256
madcowswe 0:1b2cbe8cabf1 257 /* Change the mode of the RF module to Transmitting or Receiving */
madcowswe 0:1b2cbe8cabf1 258 void RF12B::changeMode(rfmode_t _mode) {
madcowswe 0:1b2cbe8cabf1 259 mode = _mode;
madcowswe 0:1b2cbe8cabf1 260 if (_mode == TX) {
madcowswe 0:1b2cbe8cabf1 261 writeCmd(0x8239); //!er,!ebb,ET,ES,EX,!eb,!ew,DC
madcowswe 0:1b2cbe8cabf1 262 } else { /* mode == RX */
madcowswe 0:1b2cbe8cabf1 263 writeCmd(0x8299); //er,!ebb,ET,ES,EX,!eb,!ew,DC
madcowswe 0:1b2cbe8cabf1 264 }
madcowswe 0:1b2cbe8cabf1 265 }
madcowswe 0:1b2cbe8cabf1 266
madcowswe 0:1b2cbe8cabf1 267 /* Interrupt routine for data reception */
madcowswe 0:1b2cbe8cabf1 268 void RF12B::rxISR() {
madcowswe 0:1b2cbe8cabf1 269 unsigned int data = 0;
madcowswe 0:1b2cbe8cabf1 270 static int i = -2;
madcowswe 0:1b2cbe8cabf1 271 static unsigned char packet_length = 0;
madcowswe 0:1b2cbe8cabf1 272 static unsigned char crc = 0;
madcowswe 0:1b2cbe8cabf1 273 static queue<unsigned char> temp;
madcowswe 0:1b2cbe8cabf1 274
madcowswe 0:1b2cbe8cabf1 275 //Loop while interrupt is asserted
madcowswe 0:1b2cbe8cabf1 276 while (!NIRQ_in && mode == RX) {
madcowswe 0:1b2cbe8cabf1 277
madcowswe 0:1b2cbe8cabf1 278 /* Grab the packet's length byte */
madcowswe 0:1b2cbe8cabf1 279 if (i == -2) {
madcowswe 0:1b2cbe8cabf1 280 data = writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 281 if ( (data&0x8000) ) {
madcowswe 0:1b2cbe8cabf1 282 data = writeCmd(0xB000);
madcowswe 0:1b2cbe8cabf1 283 packet_length = (data&0x00FF);
madcowswe 0:1b2cbe8cabf1 284 crc = crc8(crc, packet_length);
madcowswe 0:1b2cbe8cabf1 285 i++;
madcowswe 0:1b2cbe8cabf1 286 }
madcowswe 0:1b2cbe8cabf1 287 }
madcowswe 0:1b2cbe8cabf1 288
madcowswe 0:1b2cbe8cabf1 289 //If we exhaust the interrupt, exit
madcowswe 0:1b2cbe8cabf1 290 if (NIRQ_in)
madcowswe 0:1b2cbe8cabf1 291 break;
madcowswe 0:1b2cbe8cabf1 292
madcowswe 0:1b2cbe8cabf1 293 // Check that packet length was correct
madcowswe 0:1b2cbe8cabf1 294 if (i == -1) {
madcowswe 0:1b2cbe8cabf1 295 data = writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 296 if ( (data&0x8000) ) {
madcowswe 0:1b2cbe8cabf1 297 data = writeCmd(0xB000);
madcowswe 0:1b2cbe8cabf1 298 unsigned char crcofsize = (data&0x00FF);
madcowswe 0:1b2cbe8cabf1 299 if (crcofsize != crc) {
madcowswe 0:1b2cbe8cabf1 300 //It was wrong, start over
madcowswe 0:1b2cbe8cabf1 301 i = -2;
madcowswe 0:1b2cbe8cabf1 302 packet_length = 0;
madcowswe 0:1b2cbe8cabf1 303 crc = 0;
madcowswe 0:1b2cbe8cabf1 304 temp = queue<unsigned char>();
madcowswe 0:1b2cbe8cabf1 305 resetRX();
madcowswe 0:1b2cbe8cabf1 306 } else {
madcowswe 0:1b2cbe8cabf1 307 crc = crc8(crc, crcofsize);
madcowswe 0:1b2cbe8cabf1 308 i++;
madcowswe 0:1b2cbe8cabf1 309 }
madcowswe 0:1b2cbe8cabf1 310 }
madcowswe 0:1b2cbe8cabf1 311 }
madcowswe 0:1b2cbe8cabf1 312
madcowswe 0:1b2cbe8cabf1 313 //If we exhaust the interrupt, exit
madcowswe 0:1b2cbe8cabf1 314 if (NIRQ_in)
madcowswe 0:1b2cbe8cabf1 315 break;
madcowswe 0:1b2cbe8cabf1 316
madcowswe 0:1b2cbe8cabf1 317 /* Grab the packet's data */
madcowswe 0:1b2cbe8cabf1 318 if (i >= 0 && i < packet_length) {
madcowswe 0:1b2cbe8cabf1 319 data = writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 320 if ( (data&0x8000) ) {
madcowswe 0:1b2cbe8cabf1 321 data = writeCmd(0xB000);
madcowswe 0:1b2cbe8cabf1 322 temp.push(data&0x00FF);
madcowswe 0:1b2cbe8cabf1 323 crc = crc8(crc, (unsigned char)(data&0x00FF));
madcowswe 0:1b2cbe8cabf1 324 i++;
madcowswe 0:1b2cbe8cabf1 325 }
madcowswe 0:1b2cbe8cabf1 326 }
madcowswe 0:1b2cbe8cabf1 327
madcowswe 0:1b2cbe8cabf1 328 //If we exhaust the interrupt, exit
madcowswe 0:1b2cbe8cabf1 329 if (NIRQ_in)
madcowswe 0:1b2cbe8cabf1 330 break;
madcowswe 0:1b2cbe8cabf1 331
madcowswe 0:1b2cbe8cabf1 332 if (i >= packet_length) {
madcowswe 0:1b2cbe8cabf1 333 data = writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 334 if ( (data&0x8000) ) {
madcowswe 0:1b2cbe8cabf1 335 data = writeCmd(0xB000);
madcowswe 0:1b2cbe8cabf1 336 if ((unsigned char)(data & 0x00FF) == crc) {
madcowswe 0:1b2cbe8cabf1 337 //If the checksum is correct, add our data to the end of the output buffer
madcowswe 0:1b2cbe8cabf1 338 while (!temp.empty()) {
madcowswe 0:1b2cbe8cabf1 339 fifo.push(temp.front());
madcowswe 0:1b2cbe8cabf1 340 temp.pop();
madcowswe 0:1b2cbe8cabf1 341 }
madcowswe 0:1b2cbe8cabf1 342 }
madcowswe 0:1b2cbe8cabf1 343
madcowswe 0:1b2cbe8cabf1 344 /* Tell RF Module we are finished, and clean up */
madcowswe 0:1b2cbe8cabf1 345 i = -2;
madcowswe 0:1b2cbe8cabf1 346 packet_length = 0;
madcowswe 0:1b2cbe8cabf1 347 crc = 0;
madcowswe 0:1b2cbe8cabf1 348 temp = queue<unsigned char>();
madcowswe 0:1b2cbe8cabf1 349 resetRX();
madcowswe 0:1b2cbe8cabf1 350 }
madcowswe 0:1b2cbe8cabf1 351 }
madcowswe 0:1b2cbe8cabf1 352 }
madcowswe 0:1b2cbe8cabf1 353 }
madcowswe 0:1b2cbe8cabf1 354
madcowswe 0:1b2cbe8cabf1 355 unsigned int RF12B::status() {
madcowswe 0:1b2cbe8cabf1 356 return writeCmd(0x0000);
madcowswe 0:1b2cbe8cabf1 357 }
madcowswe 0:1b2cbe8cabf1 358
madcowswe 0:1b2cbe8cabf1 359 /* Tell the RF Module this packet is received and wait for the next */
madcowswe 0:1b2cbe8cabf1 360 void RF12B::resetRX() {
madcowswe 0:1b2cbe8cabf1 361 writeCmd(0xCA81);
madcowswe 0:1b2cbe8cabf1 362 writeCmd(0xCA83);
madcowswe 0:1b2cbe8cabf1 363 };
madcowswe 0:1b2cbe8cabf1 364
madcowswe 0:1b2cbe8cabf1 365 /* Calculate CRC8 */
madcowswe 0:1b2cbe8cabf1 366 unsigned char RF12B::crc8(unsigned char crc, unsigned char data) {
madcowswe 0:1b2cbe8cabf1 367 crc = crc ^ data;
madcowswe 0:1b2cbe8cabf1 368 for (int i = 0; i < 8; i++) {
madcowswe 0:1b2cbe8cabf1 369 if (crc & 0x01) {
madcowswe 0:1b2cbe8cabf1 370 crc = (crc >> 1) ^ 0x8C;
madcowswe 0:1b2cbe8cabf1 371 } else {
madcowswe 0:1b2cbe8cabf1 372 crc >>= 1;
madcowswe 0:1b2cbe8cabf1 373 }
madcowswe 0:1b2cbe8cabf1 374 }
madcowswe 0:1b2cbe8cabf1 375 return crc;
madcowswe 0:1b2cbe8cabf1 376 }