Library to send and receive data using RF12B transceiver modules Big thanks to the tutorial at https://loee.jottit.com/rfm12b_and_avr_-_quick_start and madcowswe
Dependents: Measure_system Quadcopter_copy
RF12B.cpp@8:6fc24b44e027, 2011-03-11 (annotated)
- Committer:
- harryeakins
- Date:
- Fri Mar 11 20:40:43 2011 +0000
- Revision:
- 8:6fc24b44e027
- Parent:
- 7:9f9e2a63a8a2
- Child:
- 9:cd34784da6da
Fixed bug with ISR
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
harryeakins | 3:e72ad65868ab | 1 | #include "RF12B.h" |
harryeakins | 3:e72ad65868ab | 2 | |
harryeakins | 6:98da0571ec31 | 3 | #include "RF_defs.h" |
harryeakins | 8:6fc24b44e027 | 4 | #include <algorithm> |
harryeakins | 5:a92c3f6d1711 | 5 | |
harryeakins | 4:2a295db9ba1a | 6 | RF12B::RF12B(PinName _SDI, |
harryeakins | 4:2a295db9ba1a | 7 | PinName _SDO, |
harryeakins | 4:2a295db9ba1a | 8 | PinName _SCK, |
harryeakins | 4:2a295db9ba1a | 9 | PinName _NCS, |
harryeakins | 4:2a295db9ba1a | 10 | PinName _NIRQ):spi(_SDI, _SDO, _SCK), |
harryeakins | 5:a92c3f6d1711 | 11 | NCS(_NCS), NIRQ(_NIRQ), NIRQ_in(_NIRQ), rfled(LED3) { |
harryeakins | 3:e72ad65868ab | 12 | |
harryeakins | 4:2a295db9ba1a | 13 | /* SPI frequency, word lenght, polarity and phase */ |
harryeakins | 4:2a295db9ba1a | 14 | spi.format(16,0); |
harryeakins | 4:2a295db9ba1a | 15 | spi.frequency(2000000); |
harryeakins | 4:2a295db9ba1a | 16 | |
harryeakins | 4:2a295db9ba1a | 17 | /* Set ~CS high */ |
harryeakins | 4:2a295db9ba1a | 18 | NCS = 1; |
harryeakins | 3:e72ad65868ab | 19 | |
harryeakins | 4:2a295db9ba1a | 20 | /* Initialise RF Module */ |
harryeakins | 3:e72ad65868ab | 21 | init(); |
harryeakins | 4:2a295db9ba1a | 22 | |
harryeakins | 4:2a295db9ba1a | 23 | /* Setup interrupt to happen on falling edge of NIRQ */ |
harryeakins | 4:2a295db9ba1a | 24 | NIRQ.fall(this, &RF12B::rxISR); |
harryeakins | 3:e72ad65868ab | 25 | } |
harryeakins | 3:e72ad65868ab | 26 | |
harryeakins | 7:9f9e2a63a8a2 | 27 | /* Returns the packet length if data is available in the receive buffer, 0 otherwise*/ |
harryeakins | 7:9f9e2a63a8a2 | 28 | unsigned int RF12B::available() { |
harryeakins | 7:9f9e2a63a8a2 | 29 | return fifo.size(); |
harryeakins | 7:9f9e2a63a8a2 | 30 | } |
harryeakins | 7:9f9e2a63a8a2 | 31 | |
harryeakins | 7:9f9e2a63a8a2 | 32 | /* Reads a packet of data, with length "size" Returns false if read failed. TODO: make a metafifo to isolate packets*/ |
harryeakins | 7:9f9e2a63a8a2 | 33 | bool RF12B::read(unsigned char* data, unsigned int size) { |
harryeakins | 7:9f9e2a63a8a2 | 34 | if (fifo.size() == 0) { |
harryeakins | 7:9f9e2a63a8a2 | 35 | return false; |
harryeakins | 7:9f9e2a63a8a2 | 36 | } else { |
harryeakins | 7:9f9e2a63a8a2 | 37 | unsigned int i = 0; |
harryeakins | 7:9f9e2a63a8a2 | 38 | while (fifo.size() > 0 && i < size) { |
harryeakins | 7:9f9e2a63a8a2 | 39 | data[i++] = fifo.front(); |
harryeakins | 7:9f9e2a63a8a2 | 40 | fifo.pop(); |
harryeakins | 7:9f9e2a63a8a2 | 41 | } |
harryeakins | 7:9f9e2a63a8a2 | 42 | return true; |
harryeakins | 7:9f9e2a63a8a2 | 43 | } |
harryeakins | 4:2a295db9ba1a | 44 | } |
harryeakins | 3:e72ad65868ab | 45 | |
harryeakins | 4:2a295db9ba1a | 46 | /* Reads a byte of data from the receive buffer */ |
harryeakins | 3:e72ad65868ab | 47 | unsigned char RF12B::read() { |
harryeakins | 4:2a295db9ba1a | 48 | if (available()) { |
harryeakins | 4:2a295db9ba1a | 49 | unsigned char data = fifo.front(); |
harryeakins | 4:2a295db9ba1a | 50 | fifo.pop(); |
harryeakins | 4:2a295db9ba1a | 51 | return data; |
harryeakins | 4:2a295db9ba1a | 52 | } else { |
harryeakins | 4:2a295db9ba1a | 53 | return 0xFF; // Error val although could also be data... |
harryeakins | 3:e72ad65868ab | 54 | } |
harryeakins | 3:e72ad65868ab | 55 | } |
harryeakins | 3:e72ad65868ab | 56 | |
harryeakins | 7:9f9e2a63a8a2 | 57 | /* Sends a packet of data to the RF module for transmission TODO: Make asych*/ |
harryeakins | 4:2a295db9ba1a | 58 | void RF12B::write(unsigned char *data, unsigned char length) { |
harryeakins | 6:98da0571ec31 | 59 | unsigned char crc = 0; |
harryeakins | 8:6fc24b44e027 | 60 | |
harryeakins | 4:2a295db9ba1a | 61 | /* Transmitter mode */ |
harryeakins | 4:2a295db9ba1a | 62 | changeMode(TX); |
harryeakins | 4:2a295db9ba1a | 63 | |
harryeakins | 3:e72ad65868ab | 64 | writeCmd(0x0000); |
harryeakins | 3:e72ad65868ab | 65 | send(0xAA); // PREAMBLE |
harryeakins | 3:e72ad65868ab | 66 | send(0xAA); |
harryeakins | 3:e72ad65868ab | 67 | send(0xAA); |
harryeakins | 3:e72ad65868ab | 68 | send(0x2D); // SYNC |
harryeakins | 3:e72ad65868ab | 69 | send(0xD4); |
harryeakins | 4:2a295db9ba1a | 70 | /* Packet Length */ |
harryeakins | 4:2a295db9ba1a | 71 | send(length); |
harryeakins | 6:98da0571ec31 | 72 | crc = crc8(crc, length); |
harryeakins | 7:9f9e2a63a8a2 | 73 | send(crc); |
harryeakins | 7:9f9e2a63a8a2 | 74 | crc = crc8(crc, crc); |
harryeakins | 4:2a295db9ba1a | 75 | /* Packet Data */ |
harryeakins | 4:2a295db9ba1a | 76 | for (unsigned char i=0; i<length; i++) { |
harryeakins | 3:e72ad65868ab | 77 | send(data[i]); |
harryeakins | 6:98da0571ec31 | 78 | crc = crc8(crc, data[i]); |
harryeakins | 3:e72ad65868ab | 79 | } |
harryeakins | 6:98da0571ec31 | 80 | send(crc); |
harryeakins | 3:e72ad65868ab | 81 | send(0xAA); // DUMMY BYTES |
harryeakins | 3:e72ad65868ab | 82 | send(0xAA); |
harryeakins | 3:e72ad65868ab | 83 | send(0xAA); |
harryeakins | 3:e72ad65868ab | 84 | |
harryeakins | 4:2a295db9ba1a | 85 | /* Back to receiver mode */ |
harryeakins | 4:2a295db9ba1a | 86 | changeMode(RX); |
harryeakins | 5:a92c3f6d1711 | 87 | status(); |
harryeakins | 3:e72ad65868ab | 88 | } |
harryeakins | 3:e72ad65868ab | 89 | |
harryeakins | 4:2a295db9ba1a | 90 | /* Transmit a 1-byte data packet */ |
harryeakins | 4:2a295db9ba1a | 91 | void RF12B::write(unsigned char data) { |
harryeakins | 4:2a295db9ba1a | 92 | write(&data, 1); |
harryeakins | 3:e72ad65868ab | 93 | } |
harryeakins | 3:e72ad65868ab | 94 | |
harryeakins | 8:6fc24b44e027 | 95 | void RF12B::write(queue<char> &data, int length) { |
harryeakins | 8:6fc24b44e027 | 96 | char crc = 0; |
harryeakins | 8:6fc24b44e027 | 97 | char length_byte = 0; |
harryeakins | 8:6fc24b44e027 | 98 | |
harryeakins | 8:6fc24b44e027 | 99 | /* -1 means try to transmit everything in the queue */ |
harryeakins | 8:6fc24b44e027 | 100 | if(length == -1) { |
harryeakins | 8:6fc24b44e027 | 101 | length = data.size(); |
harryeakins | 8:6fc24b44e027 | 102 | } |
harryeakins | 8:6fc24b44e027 | 103 | |
harryeakins | 8:6fc24b44e027 | 104 | /* max length of packet is 255 */ |
harryeakins | 8:6fc24b44e027 | 105 | length_byte = min(length, 255); |
harryeakins | 8:6fc24b44e027 | 106 | |
harryeakins | 8:6fc24b44e027 | 107 | /* Transmitter mode */ |
harryeakins | 8:6fc24b44e027 | 108 | changeMode(TX); |
harryeakins | 8:6fc24b44e027 | 109 | |
harryeakins | 8:6fc24b44e027 | 110 | writeCmd(0x0000); |
harryeakins | 8:6fc24b44e027 | 111 | send(0xAA); // PREAMBLE |
harryeakins | 8:6fc24b44e027 | 112 | send(0xAA); |
harryeakins | 8:6fc24b44e027 | 113 | send(0xAA); |
harryeakins | 8:6fc24b44e027 | 114 | send(0x2D); // SYNC |
harryeakins | 8:6fc24b44e027 | 115 | send(0xD4); |
harryeakins | 8:6fc24b44e027 | 116 | /* Packet Length */ |
harryeakins | 8:6fc24b44e027 | 117 | send(length_byte); |
harryeakins | 8:6fc24b44e027 | 118 | crc = crc8(crc, length_byte); |
harryeakins | 8:6fc24b44e027 | 119 | send(crc); |
harryeakins | 8:6fc24b44e027 | 120 | crc = crc8(crc, crc); |
harryeakins | 8:6fc24b44e027 | 121 | /* Packet Data */ |
harryeakins | 8:6fc24b44e027 | 122 | for (char i=0; i<length_byte; i++) { |
harryeakins | 8:6fc24b44e027 | 123 | send(data.front()); |
harryeakins | 8:6fc24b44e027 | 124 | crc = crc8(crc, data.front()); |
harryeakins | 8:6fc24b44e027 | 125 | data.pop(); |
harryeakins | 8:6fc24b44e027 | 126 | } |
harryeakins | 8:6fc24b44e027 | 127 | send(crc); |
harryeakins | 8:6fc24b44e027 | 128 | send(0xAA); // DUMMY BYTES |
harryeakins | 8:6fc24b44e027 | 129 | send(0xAA); |
harryeakins | 8:6fc24b44e027 | 130 | send(0xAA); |
harryeakins | 8:6fc24b44e027 | 131 | |
harryeakins | 8:6fc24b44e027 | 132 | /* Back to receiver mode */ |
harryeakins | 8:6fc24b44e027 | 133 | changeMode(RX); |
harryeakins | 8:6fc24b44e027 | 134 | status(); |
harryeakins | 8:6fc24b44e027 | 135 | } |
harryeakins | 8:6fc24b44e027 | 136 | |
harryeakins | 4:2a295db9ba1a | 137 | /********************************************************************** |
harryeakins | 4:2a295db9ba1a | 138 | * PRIVATE FUNCTIONS |
harryeakins | 4:2a295db9ba1a | 139 | *********************************************************************/ |
harryeakins | 3:e72ad65868ab | 140 | |
harryeakins | 4:2a295db9ba1a | 141 | /* Initialises the RF12B module */ |
harryeakins | 3:e72ad65868ab | 142 | void RF12B::init() { |
harryeakins | 6:98da0571ec31 | 143 | /* writeCmd(0x80E7); //EL,EF,868band,12.0pF |
harryeakins | 6:98da0571ec31 | 144 | changeMode(RX); |
harryeakins | 6:98da0571ec31 | 145 | writeCmd(0xA640); //frequency select |
harryeakins | 6:98da0571ec31 | 146 | writeCmd(0xC647); //4.8kbps |
harryeakins | 6:98da0571ec31 | 147 | writeCmd(0x94A0); //VDI,FAST,134kHz,0dBm,-103dBm |
harryeakins | 6:98da0571ec31 | 148 | writeCmd(0xC2AC); //AL,!ml,DIG,DQD4 |
harryeakins | 6:98da0571ec31 | 149 | writeCmd(0xCA81); //FIFO8,SYNC,!ff,DR |
harryeakins | 6:98da0571ec31 | 150 | writeCmd(0xCED4); //SYNC=2DD4 |
harryeakins | 6:98da0571ec31 | 151 | writeCmd(0xC483); //@PWR,NO RSTRIC,!st,!fi,OE,EN |
harryeakins | 6:98da0571ec31 | 152 | writeCmd(0x9850); //!mp,90kHz,MAX OUT |
harryeakins | 7:9f9e2a63a8a2 | 153 | writeCmd(0xCC17); //OB1, COB0, LPX, Iddy, CDDIT�CBW0 |
harryeakins | 6:98da0571ec31 | 154 | writeCmd(0xE000); //NOT USED |
harryeakins | 6:98da0571ec31 | 155 | writeCmd(0xC800); //NOT USED |
harryeakins | 6:98da0571ec31 | 156 | writeCmd(0xC040); //1.66MHz,2.2V */ |
harryeakins | 6:98da0571ec31 | 157 | |
harryeakins | 6:98da0571ec31 | 158 | writeCmd( |
harryeakins | 6:98da0571ec31 | 159 | RFM_CONFIG_EL | |
harryeakins | 6:98da0571ec31 | 160 | RFM_CONFIG_EF | |
harryeakins | 6:98da0571ec31 | 161 | RFM_CONFIG_BAND_433 //| |
harryeakins | 6:98da0571ec31 | 162 | //RFM_CONFIG_X_11_0pf // meh, using default |
harryeakins | 6:98da0571ec31 | 163 | ); |
harryeakins | 6:98da0571ec31 | 164 | |
harryeakins | 6:98da0571ec31 | 165 | // 2. Power Management Command |
harryeakins | 6:98da0571ec31 | 166 | // leave everything switched off for now |
harryeakins | 6:98da0571ec31 | 167 | /* |
harryeakins | 6:98da0571ec31 | 168 | writeCmd( |
harryeakins | 6:98da0571ec31 | 169 | RFM_POWER_MANAGEMENT // switch all off |
harryeakins | 6:98da0571ec31 | 170 | ); |
harryeakins | 6:98da0571ec31 | 171 | */ |
harryeakins | 6:98da0571ec31 | 172 | |
harryeakins | 6:98da0571ec31 | 173 | // 3. Frequency Setting Command |
harryeakins | 6:98da0571ec31 | 174 | writeCmd( |
harryeakins | 6:98da0571ec31 | 175 | RFM_FREQUENCY | |
harryeakins | 6:98da0571ec31 | 176 | RFM_FREQ_433Band(435.7) //I totally made this value up... if someone knows where the sweetspots are in this band, tell me! |
harryeakins | 6:98da0571ec31 | 177 | ); |
harryeakins | 6:98da0571ec31 | 178 | |
harryeakins | 6:98da0571ec31 | 179 | |
harryeakins | 6:98da0571ec31 | 180 | // 4. Data Rate Command |
harryeakins | 6:98da0571ec31 | 181 | writeCmd(RFM_DATA_RATE_9600); |
harryeakins | 6:98da0571ec31 | 182 | |
harryeakins | 6:98da0571ec31 | 183 | |
harryeakins | 6:98da0571ec31 | 184 | // 5. Receiver Control Command |
harryeakins | 6:98da0571ec31 | 185 | writeCmd( |
harryeakins | 6:98da0571ec31 | 186 | RFM_RX_CONTROL_P20_VDI | |
harryeakins | 6:98da0571ec31 | 187 | RFM_RX_CONTROL_VDI_FAST | |
harryeakins | 6:98da0571ec31 | 188 | //RFM_RX_CONTROL_BW(RFM_BAUD_RATE) | |
harryeakins | 6:98da0571ec31 | 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) |
harryeakins | 6:98da0571ec31 | 190 | RFM_RX_CONTROL_GAIN_0 | |
harryeakins | 6:98da0571ec31 | 191 | RFM_RX_CONTROL_RSSI_103 // Might need adjustment. Datasheet says around 10^-5 bit error rate at this level and baudrate. |
harryeakins | 6:98da0571ec31 | 192 | ); |
harryeakins | 6:98da0571ec31 | 193 | |
harryeakins | 6:98da0571ec31 | 194 | // 6. Data Filter Command |
harryeakins | 6:98da0571ec31 | 195 | writeCmd( |
harryeakins | 6:98da0571ec31 | 196 | RFM_DATA_FILTER_AL | |
harryeakins | 6:98da0571ec31 | 197 | RFM_DATA_FILTER_ML | |
harryeakins | 6:98da0571ec31 | 198 | RFM_DATA_FILTER_DIG //| |
harryeakins | 6:98da0571ec31 | 199 | //RFM_DATA_FILTER_DQD(4) |
harryeakins | 6:98da0571ec31 | 200 | ); |
harryeakins | 6:98da0571ec31 | 201 | |
harryeakins | 6:98da0571ec31 | 202 | // 7. FIFO and Reset Mode Command |
harryeakins | 6:98da0571ec31 | 203 | writeCmd( |
harryeakins | 6:98da0571ec31 | 204 | RFM_FIFO_IT(8) | |
harryeakins | 6:98da0571ec31 | 205 | RFM_FIFO_DR | |
harryeakins | 6:98da0571ec31 | 206 | 0x8 //turn on 16bit sync word |
harryeakins | 6:98da0571ec31 | 207 | ); |
harryeakins | 6:98da0571ec31 | 208 | |
harryeakins | 6:98da0571ec31 | 209 | // 8. FIFO Syncword |
harryeakins | 6:98da0571ec31 | 210 | // Leave as default: 0xD4 |
harryeakins | 6:98da0571ec31 | 211 | |
harryeakins | 6:98da0571ec31 | 212 | // 9. Receiver FIFO Read |
harryeakins | 6:98da0571ec31 | 213 | // when the interupt goes high, (and if we can assume that it was a fifo fill interrupt) we can read a byte using: |
harryeakins | 6:98da0571ec31 | 214 | // result = RFM_READ_FIFO(); |
harryeakins | 6:98da0571ec31 | 215 | |
harryeakins | 6:98da0571ec31 | 216 | // 10. AFC Command |
harryeakins | 6:98da0571ec31 | 217 | writeCmd( |
harryeakins | 6:98da0571ec31 | 218 | //RFM_AFC_AUTO_VDI | //Note this might be changed to improve range. Refer to datasheet. |
harryeakins | 6:98da0571ec31 | 219 | RFM_AFC_AUTO_INDEPENDENT | |
harryeakins | 6:98da0571ec31 | 220 | RFM_AFC_RANGE_LIMIT_7_8 | |
harryeakins | 6:98da0571ec31 | 221 | RFM_AFC_EN | |
harryeakins | 6:98da0571ec31 | 222 | RFM_AFC_OE | |
harryeakins | 6:98da0571ec31 | 223 | RFM_AFC_FI |
harryeakins | 6:98da0571ec31 | 224 | ); |
harryeakins | 6:98da0571ec31 | 225 | |
harryeakins | 6:98da0571ec31 | 226 | // 11. TX Configuration Control Command |
harryeakins | 6:98da0571ec31 | 227 | writeCmd( |
harryeakins | 6:98da0571ec31 | 228 | RFM_TX_CONTROL_MOD_60 | |
harryeakins | 6:98da0571ec31 | 229 | RFM_TX_CONTROL_POW_0 |
harryeakins | 6:98da0571ec31 | 230 | ); |
harryeakins | 6:98da0571ec31 | 231 | |
harryeakins | 6:98da0571ec31 | 232 | |
harryeakins | 6:98da0571ec31 | 233 | // 12. PLL Setting Command |
harryeakins | 6:98da0571ec31 | 234 | writeCmd( |
harryeakins | 6:98da0571ec31 | 235 | 0xCC77 & ~0x01 // Setting the PLL bandwith, less noise, but max bitrate capped at 86.2 |
harryeakins | 7:9f9e2a63a8a2 | 236 | // I think this will slow down the pll's reaction time. Not sure, check with someone! |
harryeakins | 6:98da0571ec31 | 237 | ); |
harryeakins | 5:a92c3f6d1711 | 238 | |
harryeakins | 5:a92c3f6d1711 | 239 | resetRX(); |
harryeakins | 5:a92c3f6d1711 | 240 | status(); |
harryeakins | 4:2a295db9ba1a | 241 | } |
harryeakins | 3:e72ad65868ab | 242 | |
harryeakins | 4:2a295db9ba1a | 243 | /* Write a command to the RF Module */ |
harryeakins | 4:2a295db9ba1a | 244 | unsigned int RF12B::writeCmd(unsigned int cmd) { |
harryeakins | 4:2a295db9ba1a | 245 | NCS = 0; |
harryeakins | 4:2a295db9ba1a | 246 | unsigned int recv = spi.write(cmd); |
harryeakins | 4:2a295db9ba1a | 247 | NCS = 1; |
harryeakins | 4:2a295db9ba1a | 248 | return recv; |
harryeakins | 3:e72ad65868ab | 249 | } |
harryeakins | 3:e72ad65868ab | 250 | |
harryeakins | 4:2a295db9ba1a | 251 | /* Sends a byte of data across RF */ |
harryeakins | 4:2a295db9ba1a | 252 | void RF12B::send(unsigned char data) { |
harryeakins | 4:2a295db9ba1a | 253 | while (NIRQ); |
harryeakins | 4:2a295db9ba1a | 254 | writeCmd(0xB800 + data); |
harryeakins | 4:2a295db9ba1a | 255 | } |
harryeakins | 4:2a295db9ba1a | 256 | |
harryeakins | 4:2a295db9ba1a | 257 | /* Change the mode of the RF module to Transmitting or Receiving */ |
harryeakins | 8:6fc24b44e027 | 258 | void RF12B::changeMode(rfmode_t _mode) { |
harryeakins | 8:6fc24b44e027 | 259 | mode = _mode; |
harryeakins | 8:6fc24b44e027 | 260 | if (_mode == TX) { |
harryeakins | 3:e72ad65868ab | 261 | writeCmd(0x8239); //!er,!ebb,ET,ES,EX,!eb,!ew,DC |
harryeakins | 4:2a295db9ba1a | 262 | } else { /* mode == RX */ |
harryeakins | 3:e72ad65868ab | 263 | writeCmd(0x8299); //er,!ebb,ET,ES,EX,!eb,!ew,DC |
harryeakins | 3:e72ad65868ab | 264 | } |
harryeakins | 3:e72ad65868ab | 265 | } |
harryeakins | 3:e72ad65868ab | 266 | |
harryeakins | 4:2a295db9ba1a | 267 | /* Interrupt routine for data reception */ |
harryeakins | 4:2a295db9ba1a | 268 | void RF12B::rxISR() { |
harryeakins | 7:9f9e2a63a8a2 | 269 | unsigned int data = 0; |
harryeakins | 7:9f9e2a63a8a2 | 270 | static int i = -2; |
harryeakins | 7:9f9e2a63a8a2 | 271 | static unsigned char packet_length = 0; |
harryeakins | 7:9f9e2a63a8a2 | 272 | static unsigned char crc = 0; |
harryeakins | 7:9f9e2a63a8a2 | 273 | static queue<unsigned char> temp; |
harryeakins | 7:9f9e2a63a8a2 | 274 | |
harryeakins | 7:9f9e2a63a8a2 | 275 | //Loop while interrupt is asserted |
harryeakins | 8:6fc24b44e027 | 276 | while (!NIRQ_in && mode == RX) { |
harryeakins | 7:9f9e2a63a8a2 | 277 | |
harryeakins | 7:9f9e2a63a8a2 | 278 | /* Grab the packet's length byte */ |
harryeakins | 7:9f9e2a63a8a2 | 279 | if (i == -2) { |
harryeakins | 7:9f9e2a63a8a2 | 280 | data = writeCmd(0x0000); |
harryeakins | 7:9f9e2a63a8a2 | 281 | if ( (data&0x8000) ) { |
harryeakins | 7:9f9e2a63a8a2 | 282 | data = writeCmd(0xB000); |
harryeakins | 7:9f9e2a63a8a2 | 283 | packet_length = (data&0x00FF); |
harryeakins | 7:9f9e2a63a8a2 | 284 | crc = crc8(crc, packet_length); |
harryeakins | 7:9f9e2a63a8a2 | 285 | i++; |
harryeakins | 7:9f9e2a63a8a2 | 286 | } |
harryeakins | 7:9f9e2a63a8a2 | 287 | } |
harryeakins | 7:9f9e2a63a8a2 | 288 | |
harryeakins | 7:9f9e2a63a8a2 | 289 | //If we exhaust the interrupt, exit |
harryeakins | 7:9f9e2a63a8a2 | 290 | if (NIRQ_in) |
harryeakins | 7:9f9e2a63a8a2 | 291 | break; |
harryeakins | 4:2a295db9ba1a | 292 | |
harryeakins | 7:9f9e2a63a8a2 | 293 | // Check that packet length was correct |
harryeakins | 7:9f9e2a63a8a2 | 294 | if (i == -1) { |
harryeakins | 7:9f9e2a63a8a2 | 295 | data = writeCmd(0x0000); |
harryeakins | 7:9f9e2a63a8a2 | 296 | if ( (data&0x8000) ) { |
harryeakins | 7:9f9e2a63a8a2 | 297 | data = writeCmd(0xB000); |
harryeakins | 7:9f9e2a63a8a2 | 298 | unsigned char crcofsize = (data&0x00FF); |
harryeakins | 7:9f9e2a63a8a2 | 299 | if (crcofsize != crc) { |
harryeakins | 7:9f9e2a63a8a2 | 300 | //It was wrong, start over |
harryeakins | 7:9f9e2a63a8a2 | 301 | i = -2; |
harryeakins | 7:9f9e2a63a8a2 | 302 | packet_length = 0; |
harryeakins | 7:9f9e2a63a8a2 | 303 | crc = 0; |
harryeakins | 7:9f9e2a63a8a2 | 304 | temp = queue<unsigned char>(); |
harryeakins | 7:9f9e2a63a8a2 | 305 | resetRX(); |
harryeakins | 7:9f9e2a63a8a2 | 306 | } else { |
harryeakins | 7:9f9e2a63a8a2 | 307 | crc = crc8(crc, crcofsize); |
harryeakins | 7:9f9e2a63a8a2 | 308 | i++; |
harryeakins | 7:9f9e2a63a8a2 | 309 | } |
harryeakins | 7:9f9e2a63a8a2 | 310 | } |
harryeakins | 7:9f9e2a63a8a2 | 311 | } |
harryeakins | 5:a92c3f6d1711 | 312 | |
harryeakins | 7:9f9e2a63a8a2 | 313 | //If we exhaust the interrupt, exit |
harryeakins | 7:9f9e2a63a8a2 | 314 | if (NIRQ_in) |
harryeakins | 7:9f9e2a63a8a2 | 315 | break; |
harryeakins | 7:9f9e2a63a8a2 | 316 | |
harryeakins | 7:9f9e2a63a8a2 | 317 | /* Grab the packet's data */ |
harryeakins | 7:9f9e2a63a8a2 | 318 | if (i >= 0 && i < packet_length) { |
harryeakins | 5:a92c3f6d1711 | 319 | data = writeCmd(0x0000); |
harryeakins | 5:a92c3f6d1711 | 320 | if ( (data&0x8000) ) { |
harryeakins | 5:a92c3f6d1711 | 321 | data = writeCmd(0xB000); |
harryeakins | 6:98da0571ec31 | 322 | temp.push(data&0x00FF); |
harryeakins | 6:98da0571ec31 | 323 | crc = crc8(crc, (unsigned char)(data&0x00FF)); |
harryeakins | 5:a92c3f6d1711 | 324 | i++; |
harryeakins | 5:a92c3f6d1711 | 325 | } |
harryeakins | 4:2a295db9ba1a | 326 | } |
harryeakins | 7:9f9e2a63a8a2 | 327 | |
harryeakins | 7:9f9e2a63a8a2 | 328 | //If we exhaust the interrupt, exit |
harryeakins | 7:9f9e2a63a8a2 | 329 | if (NIRQ_in) |
harryeakins | 7:9f9e2a63a8a2 | 330 | break; |
harryeakins | 7:9f9e2a63a8a2 | 331 | |
harryeakins | 7:9f9e2a63a8a2 | 332 | if (i >= packet_length) { |
harryeakins | 6:98da0571ec31 | 333 | data = writeCmd(0x0000); |
harryeakins | 6:98da0571ec31 | 334 | if ( (data&0x8000) ) { |
harryeakins | 6:98da0571ec31 | 335 | data = writeCmd(0xB000); |
harryeakins | 6:98da0571ec31 | 336 | if ((unsigned char)(data & 0x00FF) == crc) { |
harryeakins | 7:9f9e2a63a8a2 | 337 | //If the checksum is correct, add our data to the end of the output buffer |
harryeakins | 6:98da0571ec31 | 338 | while (!temp.empty()) { |
harryeakins | 6:98da0571ec31 | 339 | fifo.push(temp.front()); |
harryeakins | 6:98da0571ec31 | 340 | temp.pop(); |
harryeakins | 6:98da0571ec31 | 341 | } |
harryeakins | 6:98da0571ec31 | 342 | } |
harryeakins | 7:9f9e2a63a8a2 | 343 | |
harryeakins | 7:9f9e2a63a8a2 | 344 | /* Tell RF Module we are finished, and clean up */ |
harryeakins | 7:9f9e2a63a8a2 | 345 | i = -2; |
harryeakins | 7:9f9e2a63a8a2 | 346 | packet_length = 0; |
harryeakins | 7:9f9e2a63a8a2 | 347 | crc = 0; |
harryeakins | 7:9f9e2a63a8a2 | 348 | temp = queue<unsigned char>(); |
harryeakins | 7:9f9e2a63a8a2 | 349 | resetRX(); |
harryeakins | 6:98da0571ec31 | 350 | } |
harryeakins | 6:98da0571ec31 | 351 | } |
harryeakins | 6:98da0571ec31 | 352 | } |
harryeakins | 3:e72ad65868ab | 353 | } |
harryeakins | 4:2a295db9ba1a | 354 | |
harryeakins | 5:a92c3f6d1711 | 355 | unsigned int RF12B::status() { |
harryeakins | 5:a92c3f6d1711 | 356 | return writeCmd(0x0000); |
harryeakins | 5:a92c3f6d1711 | 357 | } |
harryeakins | 5:a92c3f6d1711 | 358 | |
harryeakins | 4:2a295db9ba1a | 359 | /* Tell the RF Module this packet is received and wait for the next */ |
harryeakins | 4:2a295db9ba1a | 360 | void RF12B::resetRX() { |
harryeakins | 4:2a295db9ba1a | 361 | writeCmd(0xCA81); |
harryeakins | 4:2a295db9ba1a | 362 | writeCmd(0xCA83); |
harryeakins | 6:98da0571ec31 | 363 | }; |
harryeakins | 6:98da0571ec31 | 364 | |
harryeakins | 6:98da0571ec31 | 365 | /* Calculate CRC8 */ |
harryeakins | 6:98da0571ec31 | 366 | unsigned char RF12B::crc8(unsigned char crc, unsigned char data) { |
harryeakins | 6:98da0571ec31 | 367 | crc = crc ^ data; |
harryeakins | 6:98da0571ec31 | 368 | for (int i = 0; i < 8; i++) { |
harryeakins | 6:98da0571ec31 | 369 | if (crc & 0x01) { |
harryeakins | 6:98da0571ec31 | 370 | crc = (crc >> 1) ^ 0x8C; |
harryeakins | 6:98da0571ec31 | 371 | } else { |
harryeakins | 6:98da0571ec31 | 372 | crc >>= 1; |
harryeakins | 6:98da0571ec31 | 373 | } |
harryeakins | 6:98da0571ec31 | 374 | } |
harryeakins | 6:98da0571ec31 | 375 | return crc; |
harryeakins | 6:98da0571ec31 | 376 | } |