static void rf12_interrupt () {
// a transfer of 2x 16 bits @ 2 MHz over SPI takes 2x 8 us inside this ISR
// correction: now takes 2 + 8 µs, since sending can be done at 8 MHz
rf12_xfer(0x0000);
if (rxstate == TXRECV) {
uint8_t in = rf12_xferSlow(RF_RX_FIFO_READ);
if (rxfill == 0 && group != 0)
rf12_buf[rxfill++] = group;
rf12_buf[rxfill++] = in;
rf12_crc = _crc16_update(rf12_crc, in);
if (rxfill >= rf12_len + 5 || rxfill >= RF_MAX)
rf12_xfer(RF_IDLE_MODE);
} else {
uint8_t out;
if (rxstate < 0) {
uint8_t pos = 3 + rf12_len + rxstate++;
out = rf12_buf[pos];
rf12_crc = _crc16_update(rf12_crc, out);
} else
switch (rxstate++) {
case TXSYN1: out = 0x2D; break;
case TXSYN2: out = group; rxstate = - (2 + rf12_len); break;
case TXCRC1: out = rf12_crc; break;
case TXCRC2: out = rf12_crc >> 8; break;
case TXDONE: rf12_xfer(RF_IDLE_MODE); // fall through
default: out = 0xAA;
}
rf12_xfer(RF_TXREG_WRITE + out);
}
}
static void rf12_recvStart () {
if (rf12_fixed_pkt_len) {
rf12_len = rf12_fixed_pkt_len;
rf12_grp = rf12_hdr = 0;
rxfill = 3;
} else
rxfill = rf12_len = 0;
rf12_crc = ~0;
#if RF12_VERSION >= 2
if (group != 0)
rf12_crc = _crc16_update(~0, group);
#endif
rxstate = TXRECV;
rf12_xfer(RF_RECEIVER_ON);
}
/// @details
/// This can be used to send out slow bit-by-bit On Off Keying signals to other
/// devices such as remotely controlled power switches operating in the 433,
/// 868, or 915 MHz bands.
///
/// To use this, you need to first call rf12initialize() with a zero node ID
/// and the proper frequency band. Then call rf12onOff() in the exact timing
/// you need for sending out the signal. Once done, either call rf12onOff(0) to
/// turn the transmitter off, or reinitialize the wireless module completely
/// with a call to rf12initialize().
/// @param value Turn the transmitter on (if true) or off (if false).
/// @note The timing of this function is relatively coarse, because SPI
/// transfers are used to enable / disable the transmitter. This will add some
/// jitter to the signal, probably in the order of 10 µsec.
void rf12_onOff (uint8_t value) {
rf12_xfer(value ? RF_XMITTER_ON : RF_IDLE_MODE);
}
/// @details
/// Call this once with the node ID (0-31), frequency band (0-3), and
/// optional group (0-255 for RFM12B, only 212 allowed for RFM12).
/// @param id The ID of this wireless node. ID's should be unique within the
/// netGroup in which this node is operating. The ID range is 0 to 31,
/// but only 1..30 are available for normal use. You can pass a single
/// capital letter as node ID, with 'A' .. 'Z' corresponding to the
/// node ID's 1..26, but this convention is now discouraged. ID 0 is
/// reserved for OOK use, node ID 31 is special because it will pick
/// up packets for any node (in the same netGroup).
/// @param band This determines in which frequency range the wireless module
/// will operate. The following pre-defined constants are available:
/// RF12_433MHZ, RF12_868MHZ, RF12_915MHZ. You should use the one
/// matching the module you have, to get a useful TX/RX range.
/// @param g Net groups are used to separate nodes: only nodes in the same net
/// group can communicate with each other. Valid values are 1 to 212.
/// This parameter is optional, it defaults to 212 (0xD4) when omitted.
/// This is the only allowed value for RFM12 modules, only RFM12B
/// modules support other group values.
/// @param f Frequency correction to apply. Defaults to 1600, per RF12 docs.
/// This parameter is optional, and was added in February 2014.
/// @returns the nodeId, to be compatible with rf12_config().
///
/// Programming Tips
/// ----------------
/// Note that rf12_initialize() does not use the EEprom netId and netGroup
/// settings, nor does it change the EEPROM settings. To use the netId and
/// netGroup settings saved in EEPROM use rf12_config() instead of
/// rf12_initialize. The choice whether to use rf12_initialize() or
/// rf12_config() at the top of every sketch is one of personal preference.
/// To set EEPROM settings for use with rf12_config() use the RF12demo sketch.
uint8_t rf12_initialize (uint8_t id, uint8_t band, uint8_t g, uint16_t f) {
nodeid = id;
group = g;
frequency = f;
// caller should validate! if (frequency < 96) frequency = 1600;
rf12_spiInit();
rf12_xfer(0x0000); // initial SPI transfer added to avoid power-up problem
rf12_xfer(RF_SLEEP_MODE); // DC (disable clk pin), enable lbd
// wait until RFM12B is out of power-up reset, this takes several *seconds*
rf12_xfer(RF_TXREG_WRITE); // in case we're still in OOK mode
while (digitalRead(RFM_IRQ) == 0)
rf12_xfer(0x0000);
rf12_xfer(0x80C7 | (band << 4)); // EL (ena TX), EF (ena RX FIFO), 12.0pF
rf12_xfer(0xA000 + frequency); // 96-3960 freq range of values within band
rf12_xfer(0xC606); // approx 49.2 Kbps, i.e. 10000/29/(1+6) Kbps
rf12_xfer(0x94A2); // VDI,FAST,134kHz,0dBm,-91dBm
rf12_xfer(0xC2AC); // AL,!ml,DIG,DQD4
if (group != 0) {
rf12_xfer(0xCA83); // FIFO8,2-SYNC,!ff,DR
rf12_xfer(0xCE00 | group); // SYNC=2DXX；
} else {
rf12_xfer(0xCA8B); // FIFO8,1-SYNC,!ff,DR
rf12_xfer(0xCE2D); // SYNC=2D；
}
rf12_xfer(0xC483); // @PWR,NO RSTRIC,!st,!fi,OE,EN
rf12_xfer(0x9850); // !mp,90kHz,MAX OUT
rf12_xfer(0xCC77); // OB1，OB0, LPX,！ddy，DDIT，BW0
rf12_xfer(0xE000); // NOT USE
rf12_xfer(0xC800); // NOT USE
rf12_xfer(0xC049); // 1.66MHz,3.1V
rxstate = TXIDLE;
#if PINCHG_IRQ
#if RFM_IRQ < 8
if ((nodeid & NODE_ID) != 0) {
bitClear(DDRB, RFM_IRQ); // input
bitSet(PORTB, RFM_IRQ); // pull-up
bitSet(PCMSK0, RFM_IRQ); // pin-change
bitSet(PCICR, PCIE0); // enable
} else
bitClear(PCMSK0, RFM_IRQ);
#elif RFM_IRQ < 15
if ((nodeid & NODE_ID) != 0) {
bitClear(DDRC, RFM_IRQ - 8); // input
bitSet(PORTC, RFM_IRQ - 8); // pull-up
bitSet(PCMSK1, RFM_IRQ - 8); // pin-change
bitSet(PCICR, PCIE1); // enable
} else
bitClear(PCMSK1, RFM_IRQ - 8);
#else
if ((nodeid & NODE_ID) != 0) {
bitClear(DDRD, RFM_IRQ - 16); // input
bitSet(PORTD, RFM_IRQ - 16); // pull-up
bitSet(PCMSK2, RFM_IRQ - 16); // pin-change
bitSet(PCICR, PCIE2); // enable
} else
bitClear(PCMSK2, RFM_IRQ - 16);
#endif
#else
if ((nodeid & NODE_ID) != 0)
attachInterrupt(0, rf12_interrupt, LOW);
else
detachInterrupt(0);
#endif
return nodeid;
}
/// @details
/// Brings RFM12 in idle-mode.
static void rf12_idle() {
rfmstate &= ~B11110000; // switch off synthesizer, transmitter, receiver and baseband
rfmstate |= B00001000; // make sure crystal is running
rf12_xfer(rfmstate);
}
/// @details
/// This call provides direct access to the RFM12B registers. If you're careful
/// to avoid configuring the wireless module in a way which stops the driver
/// from functioning, this can be used to adjust frequencies, power levels,
/// RSSI threshold, etc. See the RFM12B wireless module documentation.
///
/// OBSOLETE! Use rf12_xfer instead.
///
/// This function does no longer return anything.
/// @param cmd RF12 command, topmost bits determines which register is affected.
uint16_t rf12_control(uint16_t cmd) {
return rf12_xfer(cmd);
}
/// @details
/// Handles a RFM12 interrupt depending on rxstate and the status reported by the RF
/// module.
static void rf12_interrupt() {
uint8_t in;
state = rf12_xferState(&in);
// data received or byte needed for sending
if (state & RF_FIFO_BIT) {
if (rxstate == TXRECV) { // we are receiving
if (rxfill == 0 && group != 0) {
rf12_buf[rxfill++] = group;
#if 0
if (fixedLength) {
rf12_crc8 = 0;
if (((in & 0xF0) == 0xA0) && (fixedLength > 10) && (fixedLengthBase < 10)) {
minLengthCrcOk = 10; // otherwise repeating Fine Offset packages are missed
}
else {
minLengthCrcOk = fixedLengthBase;
}
}
#endif
}
rf12_buf[rxfill++] = in;
if (fixedLength) {
#if 0
if ((rxfill == 2) && ((in & 0xF) >= 4) && ((in & 0xF) <= 5) && ((rf12_buf[1] & 0xF) == 0xA)) {
minLengthCrcOk = fixedLength;
fixedLength = 13 + 1; // ws1600 is longer
}
#endif
rf12_crc8 = _crc8_update(rf12_crc8, in);
}
else {
rf12_crc = _crc16_update(rf12_crc, in);
}
// do drssi binary-tree search
if ( drssi < 3 && ((rxfill-2)%drssi_bytes_per_decision)==0 ) {// not yet final value
// top nibble when going up, bottom one when going down
drssi = bitRead(state,8)
? (drssi_dec_tree[drssi] & B1111)
: (drssi_dec_tree[drssi] >> 4);
if ( drssi < 3 ) { // not yet final destination, set new threshold
rf12_xfer(RF_RECV_CONTROL | drssi*2+1);
}
}
// check if we got all the bytes (or maximum packet length was reached)
if (fixedLength) {
if ((rf12_crc8 == 0) && minLengthCrcOk > 0 && (rxfill >= minLengthCrcOk)) {
rf12_buf[0] = rxfill;
#if 0
while (rxfill < fixedLength) {
rf12_buf[rxfill++] = 0;
}
#endif
rf12_idle();
}
else if (rxfill >= fixedLength || rxfill >= RF_MAX) {
rf12_buf[0] = rxfill;
rf12_idle();
}
} else if (rxfill >= rf12_len + 5 || rxfill >= RF_MAX) {
rf12_idle();
}
} else { // we are sending
// access to the RFM12B internal registers with interrupts disabled
uint16_t rf12_control(uint16_t cmd) {
bitClear(EIMSK, INT0);
uint16_t r = rf12_xfer(cmd);
bitSet(EIMSK, INT0);
return r;
}
/*!
Call this once with the node ID (0-31), frequency band (0-3), and
optional group (0-255 for RF12B, only 212 allowed for RF12).
*/
void rf12_initialize () {
spi_initialize();
pinMode(RFM_IRQ, INPUT);
digitalWrite(RFM_IRQ, 1); // pull-up
rf12_xfer(0x0000); // intitial SPI transfer added to avoid power-up problem
rf12_xfer(RF_SLEEP_MODE); // DC (disable clk pin), enable lbd
// wait until RFM12B is out of power-up reset, this takes several *seconds*
rf12_xfer(RF_TXREG_WRITE); // in case we're still in OOK mode
while (digitalRead(RFM_IRQ) == 0)
rf12_xfer(0x0000);
rf12_xfer(0x80C7 | (RF12_433MHZ << 4)); // EL (ena TX), EF (ena RX FIFO), 12.0pF
rf12_xfer(0xA640); // 868MHz
rf12_xfer(0xC606); // approx 49.2 Kbps, i.e. 10000/29/(1+6) Kbps
rf12_xfer(0x94A2); // VDI,FAST,134kHz,0dBm,-91dBm
rf12_xfer(0xC2AC); // AL,!ml,DIG,DQD4
rf12_xfer(0xCA8B); // FIFO8,1-SYNC,!ff,DR
rf12_xfer(0xCE2D); // SYNC=2D；
rf12_xfer(0xC483); // @PWR,NO RSTRIC,!st,!fi,OE,EN
rf12_xfer(0x9850); // !mp,90kHz,MAX OUT
rf12_xfer(0xCC77); // OB1，OB0, LPX,！ddy，DDIT，BW0
rf12_xfer(0xE000); // NOT USE
rf12_xfer(0xC800); // NOT USE
rf12_xfer(0xC049); // 1.66MHz,3.1V
rxstate = TXIDLE;
attachInterrupt(0, rf12_interrupt, LOW);
}
