Oskar Weigl / RF12B

Working lib for qq v2

Dependents:   Sonar_Beacon

RF12B.cpp@1:09e016eea608, 2012-02-08 (annotated)

Committer:
madcowswe
Date:
Wed Feb 08 16:51:49 2012 +0000
Revision:
1:09e016eea608
Parent:
0:048b717be6c0 
Working lib for qq v2

Who changed what in which revision?

UserRevisionLine numberNew contents of line
madcowswe 0:048b717be6c0 1 #include "RF12B.h"
madcowswe 0:048b717be6c0 2
madcowswe 0:048b717be6c0 3 #include "RF_defs.h"
madcowswe 1:09e016eea608 4 #include <algorithm>
madcowswe 0:048b717be6c0 5
madcowswe 0:048b717be6c0 6 RF12B::RF12B(PinName _SDI,
madcowswe 0:048b717be6c0 7 PinName _SDO,
madcowswe 0:048b717be6c0 8 PinName _SCK,
madcowswe 0:048b717be6c0 9 PinName _NCS,
madcowswe 0:048b717be6c0 10 PinName _NIRQ):spi(_SDI, _SDO, _SCK),
madcowswe 0:048b717be6c0 11 NCS(_NCS), NIRQ(_NIRQ), NIRQ_in(_NIRQ), rfled(LED3) {
madcowswe 0:048b717be6c0 12
madcowswe 0:048b717be6c0 13 /* SPI frequency, word lenght, polarity and phase */
madcowswe 0:048b717be6c0 14 spi.format(16,0);
madcowswe 0:048b717be6c0 15 spi.frequency(2000000);
madcowswe 0:048b717be6c0 16
madcowswe 0:048b717be6c0 17 /* Set ~CS high */
madcowswe 0:048b717be6c0 18 NCS = 1;
madcowswe 0:048b717be6c0 19
madcowswe 0:048b717be6c0 20 /* Initialise RF Module */
madcowswe 0:048b717be6c0 21 init();
madcowswe 0:048b717be6c0 22
madcowswe 0:048b717be6c0 23 /* Setup interrupt to happen on falling edge of NIRQ */
madcowswe 0:048b717be6c0 24 NIRQ.fall(this, &RF12B::rxISR);
madcowswe 0:048b717be6c0 25 }
madcowswe 0:048b717be6c0 26
madcowswe 0:048b717be6c0 27 /* Returns the packet length if data is available in the receive buffer, 0 otherwise*/
madcowswe 0:048b717be6c0 28 unsigned int RF12B::available() {
madcowswe 0:048b717be6c0 29 return fifo.size();
madcowswe 0:048b717be6c0 30 }
madcowswe 0:048b717be6c0 31
madcowswe 0:048b717be6c0 32 /* Reads a packet of data, with length "size" Returns false if read failed. TODO: make a metafifo to isolate packets*/
madcowswe 0:048b717be6c0 33 bool RF12B::read(unsigned char* data, unsigned int size) {
madcowswe 0:048b717be6c0 34 if (fifo.size() == 0) {
madcowswe 0:048b717be6c0 35 return false;
madcowswe 0:048b717be6c0 36 } else {
madcowswe 0:048b717be6c0 37 unsigned int i = 0;
madcowswe 0:048b717be6c0 38 while (fifo.size() > 0 && i < size) {
madcowswe 0:048b717be6c0 39 data[i++] = fifo.front();
madcowswe 0:048b717be6c0 40 fifo.pop();
madcowswe 0:048b717be6c0 41 }
madcowswe 0:048b717be6c0 42 return true;
madcowswe 0:048b717be6c0 43 }
madcowswe 0:048b717be6c0 44 }
madcowswe 0:048b717be6c0 45
madcowswe 0:048b717be6c0 46 /* Reads a byte of data from the receive buffer */
madcowswe 0:048b717be6c0 47 unsigned char RF12B::read() {
madcowswe 0:048b717be6c0 48 if (available()) {
madcowswe 0:048b717be6c0 49 unsigned char data = fifo.front();
madcowswe 0:048b717be6c0 50 fifo.pop();
madcowswe 0:048b717be6c0 51 return data;
madcowswe 0:048b717be6c0 52 } else {
madcowswe 0:048b717be6c0 53 return 0xFF; // Error val although could also be data...
madcowswe 0:048b717be6c0 54 }
madcowswe 0:048b717be6c0 55 }
madcowswe 0:048b717be6c0 56
madcowswe 0:048b717be6c0 57 /* Sends a packet of data to the RF module for transmission TODO: Make asych*/
madcowswe 0:048b717be6c0 58 void RF12B::write(unsigned char *data, unsigned char length) {
madcowswe 0:048b717be6c0 59 unsigned char crc = 0;
madcowswe 1:09e016eea608 60
madcowswe 0:048b717be6c0 61 /* Transmitter mode */
madcowswe 0:048b717be6c0 62 changeMode(TX);
madcowswe 0:048b717be6c0 63
madcowswe 0:048b717be6c0 64 writeCmd(0x0000);
madcowswe 0:048b717be6c0 65 send(0xAA); // PREAMBLE
madcowswe 0:048b717be6c0 66 send(0xAA);
madcowswe 0:048b717be6c0 67 send(0xAA);
madcowswe 0:048b717be6c0 68 send(0x2D); // SYNC
madcowswe 0:048b717be6c0 69 send(0xD4);
madcowswe 0:048b717be6c0 70 /* Packet Length */
madcowswe 0:048b717be6c0 71 send(length);
madcowswe 0:048b717be6c0 72 crc = crc8(crc, length);
madcowswe 0:048b717be6c0 73 send(crc);
madcowswe 0:048b717be6c0 74 crc = crc8(crc, crc);
madcowswe 0:048b717be6c0 75 /* Packet Data */
madcowswe 0:048b717be6c0 76 for (unsigned char i=0; i<length; i++) {
madcowswe 0:048b717be6c0 77 send(data[i]);
madcowswe 0:048b717be6c0 78 crc = crc8(crc, data[i]);
madcowswe 0:048b717be6c0 79 }
madcowswe 0:048b717be6c0 80 send(crc);
madcowswe 0:048b717be6c0 81 send(0xAA); // DUMMY BYTES
madcowswe 0:048b717be6c0 82 send(0xAA);
madcowswe 0:048b717be6c0 83 send(0xAA);
madcowswe 0:048b717be6c0 84
madcowswe 0:048b717be6c0 85 /* Back to receiver mode */
madcowswe 0:048b717be6c0 86 changeMode(RX);
madcowswe 0:048b717be6c0 87 status();
madcowswe 0:048b717be6c0 88 }
madcowswe 0:048b717be6c0 89
madcowswe 0:048b717be6c0 90 /* Transmit a 1-byte data packet */
madcowswe 0:048b717be6c0 91 void RF12B::write(unsigned char data) {
madcowswe 0:048b717be6c0 92 write(&data, 1);
madcowswe 0:048b717be6c0 93 }
madcowswe 0:048b717be6c0 94
madcowswe 1:09e016eea608 95 void RF12B::write(queue<char> &data, int length) {
madcowswe 1:09e016eea608 96 char crc = 0;
madcowswe 1:09e016eea608 97 char length_byte = 0;
madcowswe 1:09e016eea608 98
madcowswe 1:09e016eea608 99 /* -1 means try to transmit everything in the queue */
madcowswe 1:09e016eea608 100 if(length == -1) {
madcowswe 1:09e016eea608 101 length = data.size();
madcowswe 1:09e016eea608 102 }
madcowswe 1:09e016eea608 103
madcowswe 1:09e016eea608 104 /* max length of packet is 255 */
madcowswe 1:09e016eea608 105 length_byte = min(length, 255);
madcowswe 1:09e016eea608 106
madcowswe 1:09e016eea608 107 /* Transmitter mode */
madcowswe 1:09e016eea608 108 changeMode(TX);
madcowswe 1:09e016eea608 109
madcowswe 1:09e016eea608 110 writeCmd(0x0000);
madcowswe 1:09e016eea608 111 send(0xAA); // PREAMBLE
madcowswe 1:09e016eea608 112 send(0xAA);
madcowswe 1:09e016eea608 113 send(0xAA);
madcowswe 1:09e016eea608 114 send(0x2D); // SYNC
madcowswe 1:09e016eea608 115 send(0xD4);
madcowswe 1:09e016eea608 116 /* Packet Length */
madcowswe 1:09e016eea608 117 send(length_byte);
madcowswe 1:09e016eea608 118 crc = crc8(crc, length_byte);
madcowswe 1:09e016eea608 119 send(crc);
madcowswe 1:09e016eea608 120 crc = crc8(crc, crc);
madcowswe 1:09e016eea608 121 /* Packet Data */
madcowswe 1:09e016eea608 122 for (char i=0; i<length_byte; i++) {
madcowswe 1:09e016eea608 123 send(data.front());
madcowswe 1:09e016eea608 124 crc = crc8(crc, data.front());
madcowswe 1:09e016eea608 125 data.pop();
madcowswe 1:09e016eea608 126 }
madcowswe 1:09e016eea608 127 send(crc);
madcowswe 1:09e016eea608 128 send(0xAA); // DUMMY BYTES
madcowswe 1:09e016eea608 129 send(0xAA);
madcowswe 1:09e016eea608 130 send(0xAA);
madcowswe 1:09e016eea608 131
madcowswe 1:09e016eea608 132 /* Back to receiver mode */
madcowswe 1:09e016eea608 133 changeMode(RX);
madcowswe 1:09e016eea608 134 status();
madcowswe 1:09e016eea608 135 }
madcowswe 1:09e016eea608 136
madcowswe 0:048b717be6c0 137 /**********************************************************************
madcowswe 0:048b717be6c0 138 * PRIVATE FUNCTIONS
madcowswe 0:048b717be6c0 139 *********************************************************************/
madcowswe 0:048b717be6c0 140
madcowswe 0:048b717be6c0 141 /* Initialises the RF12B module */
madcowswe 0:048b717be6c0 142 void RF12B::init() {
madcowswe 0:048b717be6c0 143 /* writeCmd(0x80E7); //EL,EF,868band,12.0pF
madcowswe 0:048b717be6c0 144 changeMode(RX);
madcowswe 0:048b717be6c0 145 writeCmd(0xA640); //frequency select
madcowswe 0:048b717be6c0 146 writeCmd(0xC647); //4.8kbps
madcowswe 0:048b717be6c0 147 writeCmd(0x94A0); //VDI,FAST,134kHz,0dBm,-103dBm
madcowswe 0:048b717be6c0 148 writeCmd(0xC2AC); //AL,!ml,DIG,DQD4
madcowswe 0:048b717be6c0 149 writeCmd(0xCA81); //FIFO8,SYNC,!ff,DR
madcowswe 0:048b717be6c0 150 writeCmd(0xCED4); //SYNC=2DD4
madcowswe 0:048b717be6c0 151 writeCmd(0xC483); //@PWR,NO RSTRIC,!st,!fi,OE,EN
madcowswe 0:048b717be6c0 152 writeCmd(0x9850); //!mp,90kHz,MAX OUT
madcowswe 0:048b717be6c0 153 writeCmd(0xCC17); //OB1, COB0, LPX, Iddy, CDDIT&#65533;CBW0
madcowswe 0:048b717be6c0 154 writeCmd(0xE000); //NOT USED
madcowswe 0:048b717be6c0 155 writeCmd(0xC800); //NOT USED
madcowswe 0:048b717be6c0 156 writeCmd(0xC040); //1.66MHz,2.2V */
madcowswe 0:048b717be6c0 157
madcowswe 0:048b717be6c0 158 writeCmd(
madcowswe 0:048b717be6c0 159 RFM_CONFIG_EL |
madcowswe 0:048b717be6c0 160 RFM_CONFIG_EF |
madcowswe 0:048b717be6c0 161 RFM_CONFIG_BAND_433 //|
madcowswe 0:048b717be6c0 162 //RFM_CONFIG_X_11_0pf // meh, using default
madcowswe 0:048b717be6c0 163 );
madcowswe 0:048b717be6c0 164
madcowswe 0:048b717be6c0 165 // 2. Power Management Command
madcowswe 0:048b717be6c0 166 // leave everything switched off for now
madcowswe 0:048b717be6c0 167 /*
madcowswe 0:048b717be6c0 168 writeCmd(
madcowswe 0:048b717be6c0 169 RFM_POWER_MANAGEMENT // switch all off
madcowswe 0:048b717be6c0 170 );
madcowswe 0:048b717be6c0 171 */
madcowswe 0:048b717be6c0 172
madcowswe 0:048b717be6c0 173 // 3. Frequency Setting Command
madcowswe 0:048b717be6c0 174 writeCmd(
madcowswe 0:048b717be6c0 175 RFM_FREQUENCY |
madcowswe 0:048b717be6c0 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 0:048b717be6c0 177 );
madcowswe 0:048b717be6c0 178
madcowswe 0:048b717be6c0 179
madcowswe 0:048b717be6c0 180 // 4. Data Rate Command
madcowswe 0:048b717be6c0 181 writeCmd(RFM_DATA_RATE_9600);
madcowswe 0:048b717be6c0 182
madcowswe 0:048b717be6c0 183
madcowswe 0:048b717be6c0 184 // 5. Receiver Control Command
madcowswe 0:048b717be6c0 185 writeCmd(
madcowswe 0:048b717be6c0 186 RFM_RX_CONTROL_P20_VDI |
madcowswe 0:048b717be6c0 187 RFM_RX_CONTROL_VDI_FAST |
madcowswe 0:048b717be6c0 188 //RFM_RX_CONTROL_BW(RFM_BAUD_RATE) |
madcowswe 0:048b717be6c0 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 0:048b717be6c0 190 RFM_RX_CONTROL_GAIN_0 |
madcowswe 0:048b717be6c0 191 RFM_RX_CONTROL_RSSI_103 // Might need adjustment. Datasheet says around 10^-5 bit error rate at this level and baudrate.
madcowswe 0:048b717be6c0 192 );
madcowswe 0:048b717be6c0 193
madcowswe 0:048b717be6c0 194 // 6. Data Filter Command
madcowswe 0:048b717be6c0 195 writeCmd(
madcowswe 0:048b717be6c0 196 RFM_DATA_FILTER_AL |
madcowswe 0:048b717be6c0 197 RFM_DATA_FILTER_ML |
madcowswe 0:048b717be6c0 198 RFM_DATA_FILTER_DIG //|
madcowswe 0:048b717be6c0 199 //RFM_DATA_FILTER_DQD(4)
madcowswe 0:048b717be6c0 200 );
madcowswe 0:048b717be6c0 201
madcowswe 0:048b717be6c0 202 // 7. FIFO and Reset Mode Command
madcowswe 0:048b717be6c0 203 writeCmd(
madcowswe 0:048b717be6c0 204 RFM_FIFO_IT(8) |
madcowswe 0:048b717be6c0 205 RFM_FIFO_DR |
madcowswe 0:048b717be6c0 206 0x8 //turn on 16bit sync word
madcowswe 0:048b717be6c0 207 );
madcowswe 0:048b717be6c0 208
madcowswe 0:048b717be6c0 209 // 8. FIFO Syncword
madcowswe 0:048b717be6c0 210 // Leave as default: 0xD4
madcowswe 0:048b717be6c0 211
madcowswe 0:048b717be6c0 212 // 9. Receiver FIFO Read
madcowswe 0:048b717be6c0 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 0:048b717be6c0 214 // result = RFM_READ_FIFO();
madcowswe 0:048b717be6c0 215
madcowswe 0:048b717be6c0 216 // 10. AFC Command
madcowswe 0:048b717be6c0 217 writeCmd(
madcowswe 0:048b717be6c0 218 //RFM_AFC_AUTO_VDI | //Note this might be changed to improve range. Refer to datasheet.
madcowswe 0:048b717be6c0 219 RFM_AFC_AUTO_INDEPENDENT |
madcowswe 0:048b717be6c0 220 RFM_AFC_RANGE_LIMIT_7_8 |
madcowswe 0:048b717be6c0 221 RFM_AFC_EN |
madcowswe 0:048b717be6c0 222 RFM_AFC_OE |
madcowswe 0:048b717be6c0 223 RFM_AFC_FI
madcowswe 0:048b717be6c0 224 );
madcowswe 0:048b717be6c0 225
madcowswe 0:048b717be6c0 226 // 11. TX Configuration Control Command
madcowswe 0:048b717be6c0 227 writeCmd(
madcowswe 0:048b717be6c0 228 RFM_TX_CONTROL_MOD_60 |
madcowswe 0:048b717be6c0 229 RFM_TX_CONTROL_POW_0
madcowswe 0:048b717be6c0 230 );
madcowswe 0:048b717be6c0 231
madcowswe 0:048b717be6c0 232
madcowswe 0:048b717be6c0 233 // 12. PLL Setting Command
madcowswe 0:048b717be6c0 234 writeCmd(
madcowswe 0:048b717be6c0 235 0xCC77 & ~0x01 // Setting the PLL bandwith, less noise, but max bitrate capped at 86.2
madcowswe 0:048b717be6c0 236 // I think this will slow down the pll's reaction time. Not sure, check with someone!
madcowswe 0:048b717be6c0 237 );
madcowswe 0:048b717be6c0 238
madcowswe 1:09e016eea608 239 changeMode(RX);
madcowswe 0:048b717be6c0 240 resetRX();
madcowswe 0:048b717be6c0 241 status();
madcowswe 0:048b717be6c0 242 }
madcowswe 0:048b717be6c0 243
madcowswe 0:048b717be6c0 244 /* Write a command to the RF Module */
madcowswe 0:048b717be6c0 245 unsigned int RF12B::writeCmd(unsigned int cmd) {
madcowswe 0:048b717be6c0 246 NCS = 0;
madcowswe 0:048b717be6c0 247 unsigned int recv = spi.write(cmd);
madcowswe 0:048b717be6c0 248 NCS = 1;
madcowswe 0:048b717be6c0 249 return recv;
madcowswe 0:048b717be6c0 250 }
madcowswe 0:048b717be6c0 251
madcowswe 0:048b717be6c0 252 /* Sends a byte of data across RF */
madcowswe 0:048b717be6c0 253 void RF12B::send(unsigned char data) {
madcowswe 0:048b717be6c0 254 while (NIRQ);
madcowswe 0:048b717be6c0 255 writeCmd(0xB800 + data);
madcowswe 0:048b717be6c0 256 }
madcowswe 0:048b717be6c0 257
madcowswe 0:048b717be6c0 258 /* Change the mode of the RF module to Transmitting or Receiving */
madcowswe 1:09e016eea608 259 void RF12B::changeMode(rfmode_t _mode) {
madcowswe 1:09e016eea608 260 mode = _mode;
madcowswe 1:09e016eea608 261 if (_mode == TX) {
madcowswe 0:048b717be6c0 262 writeCmd(0x8239); //!er,!ebb,ET,ES,EX,!eb,!ew,DC
madcowswe 0:048b717be6c0 263 } else { /* mode == RX */
madcowswe 0:048b717be6c0 264 writeCmd(0x8299); //er,!ebb,ET,ES,EX,!eb,!ew,DC
madcowswe 0:048b717be6c0 265 }
madcowswe 0:048b717be6c0 266 }
madcowswe 0:048b717be6c0 267
madcowswe 0:048b717be6c0 268 /* Interrupt routine for data reception */
madcowswe 0:048b717be6c0 269 void RF12B::rxISR() {
madcowswe 0:048b717be6c0 270 unsigned int data = 0;
madcowswe 0:048b717be6c0 271 static int i = -2;
madcowswe 0:048b717be6c0 272 static unsigned char packet_length = 0;
madcowswe 0:048b717be6c0 273 static unsigned char crc = 0;
madcowswe 0:048b717be6c0 274 static queue<unsigned char> temp;
madcowswe 0:048b717be6c0 275
madcowswe 0:048b717be6c0 276 //Loop while interrupt is asserted
madcowswe 1:09e016eea608 277 while (!NIRQ_in && mode == RX) {
madcowswe 0:048b717be6c0 278
madcowswe 0:048b717be6c0 279 /* Grab the packet's length byte */
madcowswe 0:048b717be6c0 280 if (i == -2) {
madcowswe 0:048b717be6c0 281 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 282 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 283 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 284 packet_length = (data&0x00FF);
madcowswe 0:048b717be6c0 285 crc = crc8(crc, packet_length);
madcowswe 0:048b717be6c0 286 i++;
madcowswe 0:048b717be6c0 287 }
madcowswe 0:048b717be6c0 288 }
madcowswe 0:048b717be6c0 289
madcowswe 0:048b717be6c0 290 //If we exhaust the interrupt, exit
madcowswe 0:048b717be6c0 291 if (NIRQ_in)
madcowswe 0:048b717be6c0 292 break;
madcowswe 0:048b717be6c0 293
madcowswe 0:048b717be6c0 294 // Check that packet length was correct
madcowswe 0:048b717be6c0 295 if (i == -1) {
madcowswe 0:048b717be6c0 296 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 297 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 298 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 299 unsigned char crcofsize = (data&0x00FF);
madcowswe 0:048b717be6c0 300 if (crcofsize != crc) {
madcowswe 0:048b717be6c0 301 //It was wrong, start over
madcowswe 0:048b717be6c0 302 i = -2;
madcowswe 0:048b717be6c0 303 packet_length = 0;
madcowswe 0:048b717be6c0 304 crc = 0;
madcowswe 0:048b717be6c0 305 temp = queue<unsigned char>();
madcowswe 0:048b717be6c0 306 resetRX();
madcowswe 0:048b717be6c0 307 } else {
madcowswe 0:048b717be6c0 308 crc = crc8(crc, crcofsize);
madcowswe 0:048b717be6c0 309 i++;
madcowswe 0:048b717be6c0 310 }
madcowswe 0:048b717be6c0 311 }
madcowswe 0:048b717be6c0 312 }
madcowswe 0:048b717be6c0 313
madcowswe 0:048b717be6c0 314 //If we exhaust the interrupt, exit
madcowswe 0:048b717be6c0 315 if (NIRQ_in)
madcowswe 0:048b717be6c0 316 break;
madcowswe 0:048b717be6c0 317
madcowswe 0:048b717be6c0 318 /* Grab the packet's data */
madcowswe 0:048b717be6c0 319 if (i >= 0 && i < packet_length) {
madcowswe 0:048b717be6c0 320 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 321 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 322 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 323 temp.push(data&0x00FF);
madcowswe 0:048b717be6c0 324 crc = crc8(crc, (unsigned char)(data&0x00FF));
madcowswe 0:048b717be6c0 325 i++;
madcowswe 0:048b717be6c0 326 }
madcowswe 0:048b717be6c0 327 }
madcowswe 0:048b717be6c0 328
madcowswe 0:048b717be6c0 329 //If we exhaust the interrupt, exit
madcowswe 0:048b717be6c0 330 if (NIRQ_in)
madcowswe 0:048b717be6c0 331 break;
madcowswe 0:048b717be6c0 332
madcowswe 0:048b717be6c0 333 if (i >= packet_length) {
madcowswe 0:048b717be6c0 334 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 335 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 336 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 337 if ((unsigned char)(data & 0x00FF) == crc) {
madcowswe 0:048b717be6c0 338 //If the checksum is correct, add our data to the end of the output buffer
madcowswe 0:048b717be6c0 339 while (!temp.empty()) {
madcowswe 0:048b717be6c0 340 fifo.push(temp.front());
madcowswe 0:048b717be6c0 341 temp.pop();
madcowswe 0:048b717be6c0 342 }
madcowswe 0:048b717be6c0 343 }
madcowswe 0:048b717be6c0 344
madcowswe 0:048b717be6c0 345 /* Tell RF Module we are finished, and clean up */
madcowswe 0:048b717be6c0 346 i = -2;
madcowswe 0:048b717be6c0 347 packet_length = 0;
madcowswe 0:048b717be6c0 348 crc = 0;
madcowswe 0:048b717be6c0 349 temp = queue<unsigned char>();
madcowswe 0:048b717be6c0 350 resetRX();
madcowswe 0:048b717be6c0 351 }
madcowswe 0:048b717be6c0 352 }
madcowswe 0:048b717be6c0 353 }
madcowswe 0:048b717be6c0 354 }
madcowswe 0:048b717be6c0 355
madcowswe 0:048b717be6c0 356 unsigned int RF12B::status() {
madcowswe 0:048b717be6c0 357 return writeCmd(0x0000);
madcowswe 0:048b717be6c0 358 }
madcowswe 0:048b717be6c0 359
madcowswe 0:048b717be6c0 360 /* Tell the RF Module this packet is received and wait for the next */
madcowswe 0:048b717be6c0 361 void RF12B::resetRX() {
madcowswe 0:048b717be6c0 362 writeCmd(0xCA81);
madcowswe 0:048b717be6c0 363 writeCmd(0xCA83);
madcowswe 0:048b717be6c0 364 };
madcowswe 0:048b717be6c0 365
madcowswe 0:048b717be6c0 366 /* Calculate CRC8 */
madcowswe 0:048b717be6c0 367 unsigned char RF12B::crc8(unsigned char crc, unsigned char data) {
madcowswe 0:048b717be6c0 368 crc = crc ^ data;
madcowswe 0:048b717be6c0 369 for (int i = 0; i < 8; i++) {
madcowswe 0:048b717be6c0 370 if (crc & 0x01) {
madcowswe 0:048b717be6c0 371 crc = (crc >> 1) ^ 0x8C;
madcowswe 0:048b717be6c0 372 } else {
madcowswe 0:048b717be6c0 373 crc >>= 1;
madcowswe 0:048b717be6c0 374 }
madcowswe 0:048b717be6c0 375 }
madcowswe 0:048b717be6c0 376 return crc;
madcowswe 0:048b717be6c0 377 }