Sukkin Pang / RF12B

RF12B.cpp@1:27a1606deace, 2012-01-01 (annotated)

Committer:
pangsk
Date:
Sun Jan 01 22:09:41 2012 +0000
Revision:
1:27a1606deace
Parent:
0:66fdbf2cc578
Child:
2:cfeb4c9cdbe3
Initial release.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pangsk 0:66fdbf2cc578 1 /* RF12B Library. Based on work done by JeeLabs.org ported to mbed by SK Pang.
pangsk 0:66fdbf2cc578 2 http://jeelabs.net/projects/cafe/wiki/RF12
pangsk 0:66fdbf2cc578 3
pangsk 0:66fdbf2cc578 4 http://opensource.org/licenses/mit-license.php
pangsk 0:66fdbf2cc578 5
pangsk 0:66fdbf2cc578 6 Jan 2012 skpang.co.uk
pangsk 0:66fdbf2cc578 7
pangsk 0:66fdbf2cc578 8 */
pangsk 0:66fdbf2cc578 9
pangsk 0:66fdbf2cc578 10 #include "RF12B.h"
pangsk 0:66fdbf2cc578 11
pangsk 0:66fdbf2cc578 12 // RF12 command codes
pangsk 0:66fdbf2cc578 13 #define RF_RECEIVER_ON 0x82DD
pangsk 0:66fdbf2cc578 14 #define RF_XMITTER_ON 0x823D
pangsk 0:66fdbf2cc578 15 #define RF_IDLE_MODE 0x820D
pangsk 0:66fdbf2cc578 16 #define RF_SLEEP_MODE 0x8205
pangsk 0:66fdbf2cc578 17 #define RF_WAKEUP_MODE 0x8207
pangsk 0:66fdbf2cc578 18 #define RF_TXREG_WRITE 0xB800
pangsk 0:66fdbf2cc578 19 #define RF_RX_FIFO_READ 0xB000
pangsk 0:66fdbf2cc578 20 #define RF_WAKEUP_TIMER 0xE000
pangsk 0:66fdbf2cc578 21
pangsk 0:66fdbf2cc578 22 // RF12 status bits
pangsk 0:66fdbf2cc578 23 #define RF_LBD_BIT 0x0400
pangsk 0:66fdbf2cc578 24 #define RF_RSSI_BIT 0x0100
pangsk 0:66fdbf2cc578 25
pangsk 0:66fdbf2cc578 26 // bits in the node id configuration byte
pangsk 0:66fdbf2cc578 27 #define NODE_BAND 0xC0 // frequency band
pangsk 0:66fdbf2cc578 28 #define NODE_ACKANY 0x20 // ack on broadcast packets if set
pangsk 0:66fdbf2cc578 29 #define NODE_ID 0x1F // id of this node, as A..Z or 1..31
pangsk 0:66fdbf2cc578 30
pangsk 0:66fdbf2cc578 31 // transceiver states, these determine what to do with each interrupt
pangsk 0:66fdbf2cc578 32 enum {
pangsk 0:66fdbf2cc578 33 TXCRC1, TXCRC2, TXTAIL, TXDONE, TXIDLE,
pangsk 0:66fdbf2cc578 34 TXRECV,
pangsk 0:66fdbf2cc578 35 TXPRE1, TXPRE2, TXPRE3, TXSYN1, TXSYN2,
pangsk 0:66fdbf2cc578 36 };
pangsk 0:66fdbf2cc578 37
pangsk 0:66fdbf2cc578 38 DigitalOut rfled(LED3);
pangsk 0:66fdbf2cc578 39 DigitalOut t1(p5);
pangsk 0:66fdbf2cc578 40 DigitalOut t2(p6);
pangsk 0:66fdbf2cc578 41
pangsk 0:66fdbf2cc578 42 RF12B::RF12B(PinName _SDI,
pangsk 0:66fdbf2cc578 43 PinName _SDO,
pangsk 0:66fdbf2cc578 44 PinName _SCK,
pangsk 0:66fdbf2cc578 45 PinName _NCS,
pangsk 0:66fdbf2cc578 46 PinName _NIRQ):spi(_SDI, _SDO, _SCK),
pangsk 0:66fdbf2cc578 47 NCS(_NCS), NIRQ(_NIRQ), NIRQ_in(_NIRQ), rfled(LED3),t1(p5),t2(p6) {
pangsk 0:66fdbf2cc578 48
pangsk 0:66fdbf2cc578 49 /* SPI frequency, word lenght, polarity and phase */
pangsk 0:66fdbf2cc578 50 spi.format(8,0);
pangsk 0:66fdbf2cc578 51 spi.frequency(2000000);
pangsk 0:66fdbf2cc578 52
pangsk 0:66fdbf2cc578 53 /* Set ~CS high */
pangsk 0:66fdbf2cc578 54 NCS = 1;
pangsk 0:66fdbf2cc578 55
pangsk 0:66fdbf2cc578 56 /* Setup interrupt to happen on falling edge of NIRQ */
pangsk 0:66fdbf2cc578 57 NIRQ.fall(this, &RF12B::rxISR);
pangsk 0:66fdbf2cc578 58 }
pangsk 0:66fdbf2cc578 59
pangsk 0:66fdbf2cc578 60
pangsk 0:66fdbf2cc578 61 /**********************************************************************
pangsk 0:66fdbf2cc578 62 * PRIVATE FUNCTIONS
pangsk 0:66fdbf2cc578 63 *********************************************************************/
pangsk 0:66fdbf2cc578 64
pangsk 0:66fdbf2cc578 65 /* Initialises the RF12B module */
pangsk 0:66fdbf2cc578 66 void RF12B::init(uint8_t id, uint8_t band, uint8_t g) {
pangsk 0:66fdbf2cc578 67
pangsk 0:66fdbf2cc578 68 nodeid = id;
pangsk 0:66fdbf2cc578 69 group = g;
pangsk 0:66fdbf2cc578 70 rf12_grp = g;
pangsk 0:66fdbf2cc578 71
pangsk 0:66fdbf2cc578 72 writeCmd(0x0000); // intitial SPI transfer added to avoid power-up problem
pangsk 0:66fdbf2cc578 73 writeCmd(RF_SLEEP_MODE); // DC (disable clk pin), enable lbd
pangsk 0:66fdbf2cc578 74
pangsk 0:66fdbf2cc578 75 // wait until RFM12B is out of power-up reset, this takes several *seconds*
pangsk 0:66fdbf2cc578 76 writeCmd(RF_TXREG_WRITE); // in case we're still in OOK mode
pangsk 0:66fdbf2cc578 77
pangsk 0:66fdbf2cc578 78 while (NIRQ == 0) writeCmd(0x0000);
pangsk 0:66fdbf2cc578 79
pangsk 0:66fdbf2cc578 80 writeCmd(0x80C7 | (2 << 4)); // EL (ena TX), EF (ena RX FIFO), 12.0pF
pangsk 0:66fdbf2cc578 81 writeCmd(0xA640); // 868MHz
pangsk 0:66fdbf2cc578 82 writeCmd(0xC606); // approx 49.2 Kbps, i.e. 10000/29/(1+6) Kbps
pangsk 0:66fdbf2cc578 83 writeCmd(0x94A2); // VDI,FAST,134kHz,0dBm,-91dBm
pangsk 0:66fdbf2cc578 84 writeCmd(0xC2AC); // AL,!ml,DIG,DQD4
pangsk 0:66fdbf2cc578 85
pangsk 0:66fdbf2cc578 86 writeCmd(0xCA83); // FIFO8,2-SYNC,!ff,DR
pangsk 0:66fdbf2cc578 87 writeCmd(0xCE00 | 1); // SYNC=2DXX&#65307;
pangsk 0:66fdbf2cc578 88
pangsk 0:66fdbf2cc578 89 writeCmd(0xC483); // @PWR,NO RSTRIC,!st,!fi,OE,EN
pangsk 0:66fdbf2cc578 90 writeCmd(0x9850); // !mp,90kHz,MAX OUT
pangsk 0:66fdbf2cc578 91 writeCmd(0xCC77); // OB1&#65292;OB0, LPX,&#65281;ddy&#65292;DDIT&#65292;BW0
pangsk 0:66fdbf2cc578 92 writeCmd(0xE000); // NOT USE
pangsk 0:66fdbf2cc578 93 writeCmd(0xC800); // NOT USE
pangsk 0:66fdbf2cc578 94 writeCmd(0xC049); // 1.66MHz,3.1V
pangsk 0:66fdbf2cc578 95
pangsk 0:66fdbf2cc578 96 rxstate = TXIDLE;
pangsk 0:66fdbf2cc578 97
pangsk 0:66fdbf2cc578 98 rfled = 0;
pangsk 0:66fdbf2cc578 99 }
pangsk 0:66fdbf2cc578 100
pangsk 0:66fdbf2cc578 101 /* Write a command to the RF Module */
pangsk 0:66fdbf2cc578 102 unsigned int RF12B::writeCmd(unsigned int cmd) {
pangsk 0:66fdbf2cc578 103 NCS = 0;
pangsk 0:66fdbf2cc578 104 unsigned int recv = spi.write(cmd >>8);
pangsk 0:66fdbf2cc578 105 recv = spi.write(cmd);
pangsk 0:66fdbf2cc578 106 NCS = 1;
pangsk 0:66fdbf2cc578 107 return recv;
pangsk 0:66fdbf2cc578 108 }
pangsk 0:66fdbf2cc578 109
pangsk 0:66fdbf2cc578 110 /* Sends a byte of data across RF */
pangsk 0:66fdbf2cc578 111 void RF12B::send(unsigned char data) {
pangsk 0:66fdbf2cc578 112 while (NIRQ);
pangsk 0:66fdbf2cc578 113 writeCmd(0xB800 + data);
pangsk 0:66fdbf2cc578 114 }
pangsk 0:66fdbf2cc578 115
pangsk 0:66fdbf2cc578 116
pangsk 0:66fdbf2cc578 117 /* Interrupt routine for data reception and Txing */
pangsk 0:66fdbf2cc578 118 void RF12B::rxISR() {
pangsk 0:66fdbf2cc578 119
pangsk 0:66fdbf2cc578 120 // a transfer of 2x 16 bits @ 2 MHz over SPI takes 2x 8 us inside this ISR
pangsk 0:66fdbf2cc578 121 writeCmd(0x0000);
pangsk 0:66fdbf2cc578 122
pangsk 0:66fdbf2cc578 123 if (rxstate == TXRECV) {
pangsk 0:66fdbf2cc578 124 uint8_t in = rf12_xfer(RF_RX_FIFO_READ);
pangsk 0:66fdbf2cc578 125
pangsk 0:66fdbf2cc578 126 if (rxfill == 0 && group != 0)
pangsk 0:66fdbf2cc578 127 rf12_buf[rxfill++] = group;
pangsk 0:66fdbf2cc578 128
pangsk 0:66fdbf2cc578 129 rf12_buf[rxfill++] = in;
pangsk 0:66fdbf2cc578 130 rf12_crc = _crc16_update(rf12_crc, in);
pangsk 0:66fdbf2cc578 131
pangsk 0:66fdbf2cc578 132 if (rxfill >= rf12_len + 5 || rxfill >= RF_MAX)
pangsk 0:66fdbf2cc578 133 rf12_xfer(RF_IDLE_MODE);
pangsk 0:66fdbf2cc578 134 } else {
pangsk 0:66fdbf2cc578 135 uint8_t out;
pangsk 0:66fdbf2cc578 136
pangsk 0:66fdbf2cc578 137 if (rxstate < 0) {
pangsk 0:66fdbf2cc578 138 uint8_t pos = 3 + rf12_len + rxstate++;
pangsk 0:66fdbf2cc578 139 out = rf12_buf[pos];
pangsk 0:66fdbf2cc578 140 rf12_crc = _crc16_update(rf12_crc, out);
pangsk 0:66fdbf2cc578 141 } else
pangsk 0:66fdbf2cc578 142 switch (rxstate++) {
pangsk 0:66fdbf2cc578 143 case TXSYN1: out = 0x2D; break;
pangsk 0:66fdbf2cc578 144 case TXSYN2: out = rf12_grp; rxstate = - (2 + rf12_len); break;
pangsk 0:66fdbf2cc578 145 case TXCRC1: out = rf12_crc; break;
pangsk 0:66fdbf2cc578 146 case TXCRC2: out = rf12_crc >> 8; break;
pangsk 0:66fdbf2cc578 147 case TXDONE: rf12_xfer(RF_IDLE_MODE); // fall through
pangsk 0:66fdbf2cc578 148 default: out = 0xAA;
pangsk 0:66fdbf2cc578 149 }
pangsk 0:66fdbf2cc578 150
pangsk 0:66fdbf2cc578 151 rf12_xfer(RF_TXREG_WRITE + out);
pangsk 0:66fdbf2cc578 152 }
pangsk 0:66fdbf2cc578 153 }
pangsk 0:66fdbf2cc578 154
pangsk 0:66fdbf2cc578 155
pangsk 0:66fdbf2cc578 156 void RF12B::rf12_sendStart (uint8_t hdr, const void* ptr, uint8_t len)
pangsk 0:66fdbf2cc578 157 {
pangsk 0:66fdbf2cc578 158 rf12_len = len;
pangsk 0:66fdbf2cc578 159 memcpy((void*) rf12_data, ptr, len);
pangsk 0:66fdbf2cc578 160
pangsk 0:66fdbf2cc578 161 rf12_sendStart2(hdr);
pangsk 0:66fdbf2cc578 162
pangsk 0:66fdbf2cc578 163 }
pangsk 0:66fdbf2cc578 164 void RF12B::rf12_sendStart2 (uint8_t hdr) {
pangsk 0:66fdbf2cc578 165 rf12_hdr = hdr & RF12_HDR_DST ? hdr :
pangsk 0:66fdbf2cc578 166 (hdr & ~RF12_HDR_MASK) + (nodeid & NODE_ID);
pangsk 0:66fdbf2cc578 167
pangsk 0:66fdbf2cc578 168 /* if (crypter != 0)
pangsk 0:66fdbf2cc578 169 crypter(1);
pangsk 0:66fdbf2cc578 170 */
pangsk 0:66fdbf2cc578 171 rf12_crc = ~0;
pangsk 0:66fdbf2cc578 172
pangsk 0:66fdbf2cc578 173 rf12_crc = _crc16_update(rf12_crc, rf12_grp);
pangsk 0:66fdbf2cc578 174 rxstate = TXPRE1;
pangsk 0:66fdbf2cc578 175
pangsk 0:66fdbf2cc578 176 rf12_xfer(RF_XMITTER_ON); // bytes will be fed via interrupts
pangsk 0:66fdbf2cc578 177 }
pangsk 0:66fdbf2cc578 178
pangsk 0:66fdbf2cc578 179
pangsk 0:66fdbf2cc578 180 uint16_t RF12B::rf12_xfer (uint16_t cmd) {
pangsk 0:66fdbf2cc578 181 NCS = 0;
pangsk 0:66fdbf2cc578 182 uint16_t reply = rf12_byte(cmd >> 8) << 8;
pangsk 0:66fdbf2cc578 183 reply |= rf12_byte(cmd);
pangsk 0:66fdbf2cc578 184 NCS = 1;
pangsk 0:66fdbf2cc578 185 return reply;
pangsk 0:66fdbf2cc578 186 }
pangsk 0:66fdbf2cc578 187
pangsk 0:66fdbf2cc578 188 void RF12B::rf12_recvStart (void) {
pangsk 0:66fdbf2cc578 189 rxfill = rf12_len = 0;
pangsk 0:66fdbf2cc578 190 rf12_crc = ~0;
pangsk 0:66fdbf2cc578 191
pangsk 0:66fdbf2cc578 192 if (group != 0)
pangsk 0:66fdbf2cc578 193 rf12_crc = _crc16_update(~0, group);
pangsk 0:66fdbf2cc578 194
pangsk 0:66fdbf2cc578 195 rxstate = TXRECV;
pangsk 0:66fdbf2cc578 196 rf12_xfer(RF_RECEIVER_ON);
pangsk 0:66fdbf2cc578 197 }
pangsk 0:66fdbf2cc578 198 uint16_t RF12B::check_crc(void)
pangsk 0:66fdbf2cc578 199 {
pangsk 0:66fdbf2cc578 200
pangsk 0:66fdbf2cc578 201 return rf12_crc;
pangsk 0:66fdbf2cc578 202 }
pangsk 0:66fdbf2cc578 203 uint8_t RF12B::length(void)
pangsk 0:66fdbf2cc578 204 {
pangsk 0:66fdbf2cc578 205
pangsk 0:66fdbf2cc578 206 return rf12_len;
pangsk 0:66fdbf2cc578 207 }
pangsk 0:66fdbf2cc578 208 uint8_t* RF12B::get_data(void)
pangsk 0:66fdbf2cc578 209 {
pangsk 0:66fdbf2cc578 210 return (uint8_t*)rf12_data;
pangsk 0:66fdbf2cc578 211
pangsk 0:66fdbf2cc578 212 }
pangsk 0:66fdbf2cc578 213
pangsk 0:66fdbf2cc578 214
pangsk 0:66fdbf2cc578 215 uint8_t RF12B::rf12_recvDone (void) {
pangsk 0:66fdbf2cc578 216
pangsk 1:27a1606deace 217 if (rxstate == TXRECV && (rxfill >= rf12_len + 5 || rxfill >= RF_MAX)) {
pangsk 0:66fdbf2cc578 218 rxstate = TXIDLE;
pangsk 0:66fdbf2cc578 219
pangsk 0:66fdbf2cc578 220 if (rf12_len > RF12_MAXDATA)
pangsk 0:66fdbf2cc578 221 rf12_crc = 1; // force bad crc if packet length is invalid
pangsk 0:66fdbf2cc578 222 if (!(rf12_hdr & RF12_HDR_DST) || (nodeid & NODE_ID) == 31 ||
pangsk 0:66fdbf2cc578 223 (rf12_hdr & RF12_HDR_MASK) == (nodeid & NODE_ID)) {
pangsk 0:66fdbf2cc578 224 /*
pangsk 0:66fdbf2cc578 225 for(i=0;i<rf12_len+6;i++)
pangsk 0:66fdbf2cc578 226 {
pangsk 0:66fdbf2cc578 227 printf("%X ",rf12_buf[i]);
pangsk 0:66fdbf2cc578 228 }
pangsk 0:66fdbf2cc578 229 printf(" crc:%x",rf12_crc);
pangsk 0:66fdbf2cc578 230 */
pangsk 0:66fdbf2cc578 231 /*
pangsk 0:66fdbf2cc578 232 if (rf12_crc == 0 && crypter != 0)
pangsk 0:66fdbf2cc578 233 crypter(0);
pangsk 0:66fdbf2cc578 234 else
pangsk 0:66fdbf2cc578 235 rf12_seq = -1;
pangsk 0:66fdbf2cc578 236 */
pangsk 0:66fdbf2cc578 237 return 1; // it's a broadcast packet or it's addressed to this node
pangsk 0:66fdbf2cc578 238
pangsk 0:66fdbf2cc578 239 }
pangsk 0:66fdbf2cc578 240 }
pangsk 0:66fdbf2cc578 241 if (rxstate == TXIDLE)
pangsk 0:66fdbf2cc578 242 rf12_recvStart();
pangsk 0:66fdbf2cc578 243 return 0;
pangsk 0:66fdbf2cc578 244 }
pangsk 0:66fdbf2cc578 245
pangsk 0:66fdbf2cc578 246 uint8_t RF12B::rf12_byte(uint8_t out)
pangsk 0:66fdbf2cc578 247 {
pangsk 0:66fdbf2cc578 248 unsigned char recv = spi.write(out);
pangsk 0:66fdbf2cc578 249
pangsk 0:66fdbf2cc578 250 return recv;
pangsk 0:66fdbf2cc578 251 }
pangsk 0:66fdbf2cc578 252
pangsk 0:66fdbf2cc578 253 uint16_t RF12B::_crc16_update(uint16_t crc, uint8_t data) {
pangsk 0:66fdbf2cc578 254 int i;
pangsk 0:66fdbf2cc578 255
pangsk 0:66fdbf2cc578 256 crc ^= data;
pangsk 0:66fdbf2cc578 257 for (i = 0; i < 8; ++i)
pangsk 0:66fdbf2cc578 258 {
pangsk 0:66fdbf2cc578 259 if (crc & 1)
pangsk 0:66fdbf2cc578 260 crc = (crc >> 1) ^ 0xA001;
pangsk 0:66fdbf2cc578 261 else
pangsk 0:66fdbf2cc578 262 crc = (crc >> 1);
pangsk 0:66fdbf2cc578 263 }
pangsk 0:66fdbf2cc578 264
pangsk 0:66fdbf2cc578 265 return crc;
pangsk 0:66fdbf2cc578 266 }
pangsk 0:66fdbf2cc578 267
pangsk 0:66fdbf2cc578 268
pangsk 0:66fdbf2cc578 269
pangsk 0:66fdbf2cc578 270
pangsk 0:66fdbf2cc578 271
pangsk 0:66fdbf2cc578 272
pangsk 0:66fdbf2cc578 273
pangsk 0:66fdbf2cc578 274
pangsk 0:66fdbf2cc578 275
pangsk 0:66fdbf2cc578 276