Oskar Weigl / RF12B

Working lib for qq v2

Dependents:   Sonar_Beacon

RF12B.cpp@0:048b717be6c0, 2011-03-11 (annotated)

Committer:
madcowswe
Date:
Fri Mar 11 18:02:05 2011 +0000
Revision:
0:048b717be6c0
Child:
1:09e016eea608
Made reading asynchronous, and added a block read function

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 0:048b717be6c0 4
madcowswe 0:048b717be6c0 5 DigitalOut rfled(LED3);
madcowswe 0:048b717be6c0 6
madcowswe 0:048b717be6c0 7 RF12B::RF12B(PinName _SDI,
madcowswe 0:048b717be6c0 8 PinName _SDO,
madcowswe 0:048b717be6c0 9 PinName _SCK,
madcowswe 0:048b717be6c0 10 PinName _NCS,
madcowswe 0:048b717be6c0 11 PinName _NIRQ):spi(_SDI, _SDO, _SCK),
madcowswe 0:048b717be6c0 12 NCS(_NCS), NIRQ(_NIRQ), NIRQ_in(_NIRQ), rfled(LED3) {
madcowswe 0:048b717be6c0 13
madcowswe 0:048b717be6c0 14 /* SPI frequency, word lenght, polarity and phase */
madcowswe 0:048b717be6c0 15 spi.format(16,0);
madcowswe 0:048b717be6c0 16 spi.frequency(2000000);
madcowswe 0:048b717be6c0 17
madcowswe 0:048b717be6c0 18 /* Set ~CS high */
madcowswe 0:048b717be6c0 19 NCS = 1;
madcowswe 0:048b717be6c0 20
madcowswe 0:048b717be6c0 21 /* Initialise RF Module */
madcowswe 0:048b717be6c0 22 init();
madcowswe 0:048b717be6c0 23
madcowswe 0:048b717be6c0 24 /* Setup interrupt to happen on falling edge of NIRQ */
madcowswe 0:048b717be6c0 25 NIRQ.fall(this, &RF12B::rxISR);
madcowswe 0:048b717be6c0 26 }
madcowswe 0:048b717be6c0 27
madcowswe 0:048b717be6c0 28 /* Returns the packet length if data is available in the receive buffer, 0 otherwise*/
madcowswe 0:048b717be6c0 29 unsigned int RF12B::available() {
madcowswe 0:048b717be6c0 30 return fifo.size();
madcowswe 0:048b717be6c0 31 }
madcowswe 0:048b717be6c0 32
madcowswe 0:048b717be6c0 33 /* Reads a packet of data, with length "size" Returns false if read failed. TODO: make a metafifo to isolate packets*/
madcowswe 0:048b717be6c0 34 bool RF12B::read(unsigned char* data, unsigned int size) {
madcowswe 0:048b717be6c0 35 if (fifo.size() == 0) {
madcowswe 0:048b717be6c0 36 return false;
madcowswe 0:048b717be6c0 37 } else {
madcowswe 0:048b717be6c0 38 unsigned int i = 0;
madcowswe 0:048b717be6c0 39 while (fifo.size() > 0 && i < size) {
madcowswe 0:048b717be6c0 40 data[i++] = fifo.front();
madcowswe 0:048b717be6c0 41 fifo.pop();
madcowswe 0:048b717be6c0 42 }
madcowswe 0:048b717be6c0 43 return true;
madcowswe 0:048b717be6c0 44 }
madcowswe 0:048b717be6c0 45 }
madcowswe 0:048b717be6c0 46
madcowswe 0:048b717be6c0 47 /* Reads a byte of data from the receive buffer */
madcowswe 0:048b717be6c0 48 unsigned char RF12B::read() {
madcowswe 0:048b717be6c0 49 if (available()) {
madcowswe 0:048b717be6c0 50 unsigned char data = fifo.front();
madcowswe 0:048b717be6c0 51 fifo.pop();
madcowswe 0:048b717be6c0 52 return data;
madcowswe 0:048b717be6c0 53 } else {
madcowswe 0:048b717be6c0 54 return 0xFF; // Error val although could also be data...
madcowswe 0:048b717be6c0 55 }
madcowswe 0:048b717be6c0 56 }
madcowswe 0:048b717be6c0 57
madcowswe 0:048b717be6c0 58 /* Sends a packet of data to the RF module for transmission TODO: Make asych*/
madcowswe 0:048b717be6c0 59 void RF12B::write(unsigned char *data, unsigned char length) {
madcowswe 0:048b717be6c0 60 unsigned char crc = 0;
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 0:048b717be6c0 95 /**********************************************************************
madcowswe 0:048b717be6c0 96 * PRIVATE FUNCTIONS
madcowswe 0:048b717be6c0 97 *********************************************************************/
madcowswe 0:048b717be6c0 98
madcowswe 0:048b717be6c0 99 /* Initialises the RF12B module */
madcowswe 0:048b717be6c0 100 void RF12B::init() {
madcowswe 0:048b717be6c0 101 /* writeCmd(0x80E7); //EL,EF,868band,12.0pF
madcowswe 0:048b717be6c0 102 changeMode(RX);
madcowswe 0:048b717be6c0 103 writeCmd(0xA640); //frequency select
madcowswe 0:048b717be6c0 104 writeCmd(0xC647); //4.8kbps
madcowswe 0:048b717be6c0 105 writeCmd(0x94A0); //VDI,FAST,134kHz,0dBm,-103dBm
madcowswe 0:048b717be6c0 106 writeCmd(0xC2AC); //AL,!ml,DIG,DQD4
madcowswe 0:048b717be6c0 107 writeCmd(0xCA81); //FIFO8,SYNC,!ff,DR
madcowswe 0:048b717be6c0 108 writeCmd(0xCED4); //SYNC=2DD4
madcowswe 0:048b717be6c0 109 writeCmd(0xC483); //@PWR,NO RSTRIC,!st,!fi,OE,EN
madcowswe 0:048b717be6c0 110 writeCmd(0x9850); //!mp,90kHz,MAX OUT
madcowswe 0:048b717be6c0 111 writeCmd(0xCC17); //OB1, COB0, LPX, Iddy, CDDIT&#65533;CBW0
madcowswe 0:048b717be6c0 112 writeCmd(0xE000); //NOT USED
madcowswe 0:048b717be6c0 113 writeCmd(0xC800); //NOT USED
madcowswe 0:048b717be6c0 114 writeCmd(0xC040); //1.66MHz,2.2V */
madcowswe 0:048b717be6c0 115
madcowswe 0:048b717be6c0 116 writeCmd(
madcowswe 0:048b717be6c0 117 RFM_CONFIG_EL |
madcowswe 0:048b717be6c0 118 RFM_CONFIG_EF |
madcowswe 0:048b717be6c0 119 RFM_CONFIG_BAND_433 //|
madcowswe 0:048b717be6c0 120 //RFM_CONFIG_X_11_0pf // meh, using default
madcowswe 0:048b717be6c0 121 );
madcowswe 0:048b717be6c0 122
madcowswe 0:048b717be6c0 123 // 2. Power Management Command
madcowswe 0:048b717be6c0 124 // leave everything switched off for now
madcowswe 0:048b717be6c0 125 /*
madcowswe 0:048b717be6c0 126 writeCmd(
madcowswe 0:048b717be6c0 127 RFM_POWER_MANAGEMENT // switch all off
madcowswe 0:048b717be6c0 128 );
madcowswe 0:048b717be6c0 129 */
madcowswe 0:048b717be6c0 130
madcowswe 0:048b717be6c0 131 // 3. Frequency Setting Command
madcowswe 0:048b717be6c0 132 writeCmd(
madcowswe 0:048b717be6c0 133 RFM_FREQUENCY |
madcowswe 0:048b717be6c0 134 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 135 );
madcowswe 0:048b717be6c0 136
madcowswe 0:048b717be6c0 137
madcowswe 0:048b717be6c0 138 // 4. Data Rate Command
madcowswe 0:048b717be6c0 139 writeCmd(RFM_DATA_RATE_9600);
madcowswe 0:048b717be6c0 140
madcowswe 0:048b717be6c0 141
madcowswe 0:048b717be6c0 142 // 5. Receiver Control Command
madcowswe 0:048b717be6c0 143 writeCmd(
madcowswe 0:048b717be6c0 144 RFM_RX_CONTROL_P20_VDI |
madcowswe 0:048b717be6c0 145 RFM_RX_CONTROL_VDI_FAST |
madcowswe 0:048b717be6c0 146 //RFM_RX_CONTROL_BW(RFM_BAUD_RATE) |
madcowswe 0:048b717be6c0 147 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 148 RFM_RX_CONTROL_GAIN_0 |
madcowswe 0:048b717be6c0 149 RFM_RX_CONTROL_RSSI_103 // Might need adjustment. Datasheet says around 10^-5 bit error rate at this level and baudrate.
madcowswe 0:048b717be6c0 150 );
madcowswe 0:048b717be6c0 151
madcowswe 0:048b717be6c0 152 // 6. Data Filter Command
madcowswe 0:048b717be6c0 153 writeCmd(
madcowswe 0:048b717be6c0 154 RFM_DATA_FILTER_AL |
madcowswe 0:048b717be6c0 155 RFM_DATA_FILTER_ML |
madcowswe 0:048b717be6c0 156 RFM_DATA_FILTER_DIG //|
madcowswe 0:048b717be6c0 157 //RFM_DATA_FILTER_DQD(4)
madcowswe 0:048b717be6c0 158 );
madcowswe 0:048b717be6c0 159
madcowswe 0:048b717be6c0 160 // 7. FIFO and Reset Mode Command
madcowswe 0:048b717be6c0 161 writeCmd(
madcowswe 0:048b717be6c0 162 RFM_FIFO_IT(8) |
madcowswe 0:048b717be6c0 163 RFM_FIFO_DR |
madcowswe 0:048b717be6c0 164 0x8 //turn on 16bit sync word
madcowswe 0:048b717be6c0 165 );
madcowswe 0:048b717be6c0 166
madcowswe 0:048b717be6c0 167 // 8. FIFO Syncword
madcowswe 0:048b717be6c0 168 // Leave as default: 0xD4
madcowswe 0:048b717be6c0 169
madcowswe 0:048b717be6c0 170 // 9. Receiver FIFO Read
madcowswe 0:048b717be6c0 171 // 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 172 // result = RFM_READ_FIFO();
madcowswe 0:048b717be6c0 173
madcowswe 0:048b717be6c0 174 // 10. AFC Command
madcowswe 0:048b717be6c0 175 writeCmd(
madcowswe 0:048b717be6c0 176 //RFM_AFC_AUTO_VDI | //Note this might be changed to improve range. Refer to datasheet.
madcowswe 0:048b717be6c0 177 RFM_AFC_AUTO_INDEPENDENT |
madcowswe 0:048b717be6c0 178 RFM_AFC_RANGE_LIMIT_7_8 |
madcowswe 0:048b717be6c0 179 RFM_AFC_EN |
madcowswe 0:048b717be6c0 180 RFM_AFC_OE |
madcowswe 0:048b717be6c0 181 RFM_AFC_FI
madcowswe 0:048b717be6c0 182 );
madcowswe 0:048b717be6c0 183
madcowswe 0:048b717be6c0 184 // 11. TX Configuration Control Command
madcowswe 0:048b717be6c0 185 writeCmd(
madcowswe 0:048b717be6c0 186 RFM_TX_CONTROL_MOD_60 |
madcowswe 0:048b717be6c0 187 RFM_TX_CONTROL_POW_0
madcowswe 0:048b717be6c0 188 );
madcowswe 0:048b717be6c0 189
madcowswe 0:048b717be6c0 190
madcowswe 0:048b717be6c0 191 // 12. PLL Setting Command
madcowswe 0:048b717be6c0 192 writeCmd(
madcowswe 0:048b717be6c0 193 0xCC77 & ~0x01 // Setting the PLL bandwith, less noise, but max bitrate capped at 86.2
madcowswe 0:048b717be6c0 194 // I think this will slow down the pll's reaction time. Not sure, check with someone!
madcowswe 0:048b717be6c0 195 );
madcowswe 0:048b717be6c0 196
madcowswe 0:048b717be6c0 197 resetRX();
madcowswe 0:048b717be6c0 198 status();
madcowswe 0:048b717be6c0 199 }
madcowswe 0:048b717be6c0 200
madcowswe 0:048b717be6c0 201 /* Write a command to the RF Module */
madcowswe 0:048b717be6c0 202 unsigned int RF12B::writeCmd(unsigned int cmd) {
madcowswe 0:048b717be6c0 203 NCS = 0;
madcowswe 0:048b717be6c0 204 unsigned int recv = spi.write(cmd);
madcowswe 0:048b717be6c0 205 NCS = 1;
madcowswe 0:048b717be6c0 206 return recv;
madcowswe 0:048b717be6c0 207 }
madcowswe 0:048b717be6c0 208
madcowswe 0:048b717be6c0 209 /* Sends a byte of data across RF */
madcowswe 0:048b717be6c0 210 void RF12B::send(unsigned char data) {
madcowswe 0:048b717be6c0 211 while (NIRQ);
madcowswe 0:048b717be6c0 212 writeCmd(0xB800 + data);
madcowswe 0:048b717be6c0 213 }
madcowswe 0:048b717be6c0 214
madcowswe 0:048b717be6c0 215 /* Change the mode of the RF module to Transmitting or Receiving */
madcowswe 0:048b717be6c0 216 void RF12B::changeMode(rfmode_t mode) {
madcowswe 0:048b717be6c0 217 if (mode == TX) {
madcowswe 0:048b717be6c0 218 writeCmd(0x8239); //!er,!ebb,ET,ES,EX,!eb,!ew,DC
madcowswe 0:048b717be6c0 219 } else { /* mode == RX */
madcowswe 0:048b717be6c0 220 writeCmd(0x8299); //er,!ebb,ET,ES,EX,!eb,!ew,DC
madcowswe 0:048b717be6c0 221 }
madcowswe 0:048b717be6c0 222 }
madcowswe 0:048b717be6c0 223
madcowswe 0:048b717be6c0 224 /* Interrupt routine for data reception */
madcowswe 0:048b717be6c0 225 void RF12B::rxISR() {
madcowswe 0:048b717be6c0 226 unsigned int data = 0;
madcowswe 0:048b717be6c0 227 static int i = -2;
madcowswe 0:048b717be6c0 228 static unsigned char packet_length = 0;
madcowswe 0:048b717be6c0 229 static unsigned char crc = 0;
madcowswe 0:048b717be6c0 230 static queue<unsigned char> temp;
madcowswe 0:048b717be6c0 231
madcowswe 0:048b717be6c0 232 //Loop while interrupt is asserted
madcowswe 0:048b717be6c0 233 while (!NIRQ_in) {
madcowswe 0:048b717be6c0 234
madcowswe 0:048b717be6c0 235 /* Grab the packet's length byte */
madcowswe 0:048b717be6c0 236 if (i == -2) {
madcowswe 0:048b717be6c0 237 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 238 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 239 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 240 packet_length = (data&0x00FF);
madcowswe 0:048b717be6c0 241 crc = crc8(crc, packet_length);
madcowswe 0:048b717be6c0 242 i++;
madcowswe 0:048b717be6c0 243 }
madcowswe 0:048b717be6c0 244 }
madcowswe 0:048b717be6c0 245
madcowswe 0:048b717be6c0 246 //If we exhaust the interrupt, exit
madcowswe 0:048b717be6c0 247 if (NIRQ_in)
madcowswe 0:048b717be6c0 248 break;
madcowswe 0:048b717be6c0 249
madcowswe 0:048b717be6c0 250 // Check that packet length was correct
madcowswe 0:048b717be6c0 251 if (i == -1) {
madcowswe 0:048b717be6c0 252 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 253 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 254 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 255 unsigned char crcofsize = (data&0x00FF);
madcowswe 0:048b717be6c0 256 if (crcofsize != crc) {
madcowswe 0:048b717be6c0 257 //It was wrong, start over
madcowswe 0:048b717be6c0 258 i = -2;
madcowswe 0:048b717be6c0 259 packet_length = 0;
madcowswe 0:048b717be6c0 260 crc = 0;
madcowswe 0:048b717be6c0 261 temp = queue<unsigned char>();
madcowswe 0:048b717be6c0 262 resetRX();
madcowswe 0:048b717be6c0 263 } else {
madcowswe 0:048b717be6c0 264 crc = crc8(crc, crcofsize);
madcowswe 0:048b717be6c0 265 i++;
madcowswe 0:048b717be6c0 266 }
madcowswe 0:048b717be6c0 267 }
madcowswe 0:048b717be6c0 268 }
madcowswe 0:048b717be6c0 269
madcowswe 0:048b717be6c0 270 //If we exhaust the interrupt, exit
madcowswe 0:048b717be6c0 271 if (NIRQ_in)
madcowswe 0:048b717be6c0 272 break;
madcowswe 0:048b717be6c0 273
madcowswe 0:048b717be6c0 274 /* Grab the packet's data */
madcowswe 0:048b717be6c0 275 if (i >= 0 && i < packet_length) {
madcowswe 0:048b717be6c0 276 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 277 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 278 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 279 temp.push(data&0x00FF);
madcowswe 0:048b717be6c0 280 crc = crc8(crc, (unsigned char)(data&0x00FF));
madcowswe 0:048b717be6c0 281 i++;
madcowswe 0:048b717be6c0 282 }
madcowswe 0:048b717be6c0 283 }
madcowswe 0:048b717be6c0 284
madcowswe 0:048b717be6c0 285 //If we exhaust the interrupt, exit
madcowswe 0:048b717be6c0 286 if (NIRQ_in)
madcowswe 0:048b717be6c0 287 break;
madcowswe 0:048b717be6c0 288
madcowswe 0:048b717be6c0 289 if (i >= packet_length) {
madcowswe 0:048b717be6c0 290 data = writeCmd(0x0000);
madcowswe 0:048b717be6c0 291 if ( (data&0x8000) ) {
madcowswe 0:048b717be6c0 292 data = writeCmd(0xB000);
madcowswe 0:048b717be6c0 293 if ((unsigned char)(data & 0x00FF) == crc) {
madcowswe 0:048b717be6c0 294 //If the checksum is correct, add our data to the end of the output buffer
madcowswe 0:048b717be6c0 295 while (!temp.empty()) {
madcowswe 0:048b717be6c0 296 fifo.push(temp.front());
madcowswe 0:048b717be6c0 297 temp.pop();
madcowswe 0:048b717be6c0 298 }
madcowswe 0:048b717be6c0 299 }
madcowswe 0:048b717be6c0 300
madcowswe 0:048b717be6c0 301 /* Tell RF Module we are finished, and clean up */
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 }
madcowswe 0:048b717be6c0 308 }
madcowswe 0:048b717be6c0 309 }
madcowswe 0:048b717be6c0 310 }
madcowswe 0:048b717be6c0 311
madcowswe 0:048b717be6c0 312 unsigned int RF12B::status() {
madcowswe 0:048b717be6c0 313 return writeCmd(0x0000);
madcowswe 0:048b717be6c0 314 }
madcowswe 0:048b717be6c0 315
madcowswe 0:048b717be6c0 316 /* Tell the RF Module this packet is received and wait for the next */
madcowswe 0:048b717be6c0 317 void RF12B::resetRX() {
madcowswe 0:048b717be6c0 318 writeCmd(0xCA81);
madcowswe 0:048b717be6c0 319 writeCmd(0xCA83);
madcowswe 0:048b717be6c0 320 };
madcowswe 0:048b717be6c0 321
madcowswe 0:048b717be6c0 322 /* Calculate CRC8 */
madcowswe 0:048b717be6c0 323 unsigned char RF12B::crc8(unsigned char crc, unsigned char data) {
madcowswe 0:048b717be6c0 324 crc = crc ^ data;
madcowswe 0:048b717be6c0 325 for (int i = 0; i < 8; i++) {
madcowswe 0:048b717be6c0 326 if (crc & 0x01) {
madcowswe 0:048b717be6c0 327 crc = (crc >> 1) ^ 0x8C;
madcowswe 0:048b717be6c0 328 } else {
madcowswe 0:048b717be6c0 329 crc >>= 1;
madcowswe 0:048b717be6c0 330 }
madcowswe 0:048b717be6c0 331 }
madcowswe 0:048b717be6c0 332 return crc;
madcowswe 0:048b717be6c0 333 }