RFM69.cpp

00001 //Port of RFM69 from lowpowerlab
00002 //Sync'd Feb. 6, 2015
00003 //spi register read/write routines from Karl Zweimuller's RF22
00004 //
00005 //
00006 //
00007 // **********************************************************************************
00008 // Driver definition for HopeRF RFM69W/RFM69HW/RFM69CW/RFM69HCW, Semtech SX1231/1231H
00009 // **********************************************************************************
00010 // Copyright Felix Rusu (2014), felix@lowpowerlab.com
00011 // http://lowpowerlab.com/
00012 // **********************************************************************************
00013 // License
00014 // **********************************************************************************
00015 // This program is free software; you can redistribute it 
00016 // and/or modify it under the terms of the GNU General    
00017 // Public License as published by the Free Software       
00018 // Foundation; either version 3 of the License, or        
00019 // (at your option) any later version.                    
00020 //                                                        
00021 // This program is distributed in the hope that it will   
00022 // be useful, but WITHOUT ANY WARRANTY; without even the  
00023 // implied warranty of MERCHANTABILITY or FITNESS FOR A   
00024 // PARTICULAR PURPOSE. See the GNU General Public        
00025 // License for more details.                              
00026 //                                                        
00027 // You should have received a copy of the GNU General    
00028 // Public License along with this program.
00029 // If not, see <http://www.gnu.org/licenses/>.
00030 //                                                        
00031 // Licence can be viewed at                               
00032 // http://www.gnu.org/licenses/gpl-3.0.txt
00033 //
00034 // Please maintain this license information along with authorship
00035 // and copyright notices in any redistribution of this code
00036 // **********************************************************************************// RF22.cpp
00037 //
00038 // Copyright (C) 2011 Mike McCauley
00039 // $Id: RF22.cpp,v 1.17 2013/02/06 21:33:56 mikem Exp mikem $
00040 // ported to mbed by Karl Zweimueller
00041 
00042 
00043 #include "mbed.h"
00044 #include "RFM69.h"
00045 #include <RFM69registers.h>
00046 #include <SPI.h>
00047 
00048 volatile uint8_t RFM69::DATA[RF69_MAX_DATA_LEN];
00049 volatile uint8_t RFM69::_mode;        // current transceiver state
00050 volatile uint8_t RFM69::DATALEN;
00051 volatile uint8_t RFM69::SENDERID;
00052 volatile uint8_t RFM69::TARGETID;     // should match _address
00053 volatile uint8_t RFM69::PAYLOADLEN;
00054 volatile uint8_t RFM69::ACK_REQUESTED;
00055 volatile uint8_t RFM69::ACK_RECEIVED; // should be polled immediately after sending a packet with ACK request
00056 volatile int16_t RFM69::RSSI;          // most accurate RSSI during reception (closest to the reception)
00057 
00058 RFM69::RFM69(PinName mosi, PinName miso, PinName sclk, PinName slaveSelectPin, PinName interrupt): 
00059       _slaveSelectPin(slaveSelectPin) ,  _spi(mosi, miso, sclk), _interrupt(interrupt) {
00060  
00061     // Setup the spi for 8 bit data, high steady state clock,
00062     // second edge capture, with a 1MHz clock rate
00063     _spi.format(8,0);
00064     _spi.frequency(4000000);
00065     _mode = RF69_MODE_STANDBY;
00066     _promiscuousMode = false;
00067     _powerLevel = 31;
00068 }
00069 
00070 bool RFM69::initialize(uint8_t freqBand, uint8_t nodeID, uint8_t networkID)
00071 {
00072   unsigned long start_to;
00073   const uint8_t CONFIG[][2] =
00074   {
00075     /* 0x01 */ { REG_OPMODE, RF_OPMODE_SEQUENCER_ON | RF_OPMODE_LISTEN_OFF | RF_OPMODE_STANDBY },
00076     /* 0x02 */ { REG_DATAMODUL, RF_DATAMODUL_DATAMODE_PACKET | RF_DATAMODUL_MODULATIONTYPE_FSK | RF_DATAMODUL_MODULATIONSHAPING_00 }, // no shaping
00077     /* 0x03 */ { REG_BITRATEMSB, RF_BITRATEMSB_55555}, // default: 4.8 KBPS
00078     /* 0x04 */ { REG_BITRATELSB, RF_BITRATELSB_55555},
00079     /* 0x05 */ { REG_FDEVMSB, RF_FDEVMSB_50000}, // default: 5KHz, (FDEV + BitRate / 2 <= 500KHz)
00080     /* 0x06 */ { REG_FDEVLSB, RF_FDEVLSB_50000},
00081 
00082     /* 0x07 */ { REG_FRFMSB, (uint8_t) (freqBand==RF69_315MHZ ? RF_FRFMSB_315 : (freqBand==RF69_433MHZ ? RF_FRFMSB_433 : (freqBand==RF69_868MHZ ? RF_FRFMSB_868 : RF_FRFMSB_915))) },
00083     /* 0x08 */ { REG_FRFMID, (uint8_t) (freqBand==RF69_315MHZ ? RF_FRFMID_315 : (freqBand==RF69_433MHZ ? RF_FRFMID_433 : (freqBand==RF69_868MHZ ? RF_FRFMID_868 : RF_FRFMID_915))) },
00084     /* 0x09 */ { REG_FRFLSB, (uint8_t) (freqBand==RF69_315MHZ ? RF_FRFLSB_315 : (freqBand==RF69_433MHZ ? RF_FRFLSB_433 : (freqBand==RF69_868MHZ ? RF_FRFLSB_868 : RF_FRFLSB_915))) },
00085 
00086     // looks like PA1 and PA2 are not implemented on RFM69W, hence the max output power is 13dBm
00087     // +17dBm and +20dBm are possible on RFM69HW
00088     // +13dBm formula: Pout = -18 + OutputPower (with PA0 or PA1**)
00089     // +17dBm formula: Pout = -14 + OutputPower (with PA1 and PA2)**
00090     // +20dBm formula: Pout = -11 + OutputPower (with PA1 and PA2)** and high power PA settings (section 3.3.7 in datasheet)
00091     ///* 0x11 */ { REG_PALEVEL, RF_PALEVEL_PA0_ON | RF_PALEVEL_PA1_OFF | RF_PALEVEL_PA2_OFF | RF_PALEVEL_OUTPUTPOWER_11111},
00092     ///* 0x13 */ { REG_OCP, RF_OCP_ON | RF_OCP_TRIM_95 }, // over current protection (default is 95mA)
00093 
00094     // RXBW defaults are { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_24 | RF_RXBW_EXP_5} (RxBw: 10.4KHz)
00095     /* 0x19 */ { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_16 | RF_RXBW_EXP_2 }, // (BitRate < 2 * RxBw)
00096     //for BR-19200: /* 0x19 */ { REG_RXBW, RF_RXBW_DCCFREQ_010 | RF_RXBW_MANT_24 | RF_RXBW_EXP_3 },
00097     /* 0x25 */ { REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_01 }, // DIO0 is the only IRQ we're using
00098     /* 0x26 */ { REG_DIOMAPPING2, RF_DIOMAPPING2_CLKOUT_OFF }, // DIO5 ClkOut disable for power saving
00099     /* 0x28 */ { REG_IRQFLAGS2, RF_IRQFLAGS2_FIFOOVERRUN }, // writing to this bit ensures that the FIFO & status flags are reset
00100     /* 0x29 */ { REG_RSSITHRESH, 220 }, // must be set to dBm = (-Sensitivity / 2), default is 0xE4 = 228 so -114dBm
00101     ///* 0x2D */ { REG_PREAMBLELSB, RF_PREAMBLESIZE_LSB_VALUE } // default 3 preamble bytes 0xAAAAAA
00102     /* 0x2E */ { REG_SYNCCONFIG, RF_SYNC_ON | RF_SYNC_FIFOFILL_AUTO | RF_SYNC_SIZE_2 | RF_SYNC_TOL_0 },
00103     /* 0x2F */ { REG_SYNCVALUE1, 0x2D },      // attempt to make this compatible with sync1 byte of RFM12B lib
00104     /* 0x30 */ { REG_SYNCVALUE2, networkID }, // NETWORK ID
00105     /* 0x37 */ { REG_PACKETCONFIG1, RF_PACKET1_FORMAT_VARIABLE | RF_PACKET1_DCFREE_OFF | RF_PACKET1_CRC_ON | RF_PACKET1_CRCAUTOCLEAR_ON | RF_PACKET1_ADRSFILTERING_OFF },
00106     /* 0x38 */ { REG_PAYLOADLENGTH, 66 }, // in variable length mode: the max frame size, not used in TX
00107     ///* 0x39 */ { REG_NODEADRS, nodeID }, // turned off because we're not using address filtering
00108     /* 0x3C */ { REG_FIFOTHRESH, RF_FIFOTHRESH_TXSTART_FIFONOTEMPTY | RF_FIFOTHRESH_VALUE }, // TX on FIFO not empty
00109     /* 0x3D */ { REG_PACKETCONFIG2, RF_PACKET2_RXRESTARTDELAY_2BITS | RF_PACKET2_AUTORXRESTART_ON | RF_PACKET2_AES_OFF }, // RXRESTARTDELAY must match transmitter PA ramp-down time (bitrate dependent)
00110     //for BR-19200: /* 0x3D */ { REG_PACKETCONFIG2, RF_PACKET2_RXRESTARTDELAY_NONE | RF_PACKET2_AUTORXRESTART_ON | RF_PACKET2_AES_OFF }, // RXRESTARTDELAY must match transmitter PA ramp-down time (bitrate dependent)
00111     /* 0x6F */ { REG_TESTDAGC, RF_DAGC_IMPROVED_LOWBETA0 }, // run DAGC continuously in RX mode for Fading Margin Improvement, recommended default for AfcLowBetaOn=0
00112     {255, 0}
00113   };
00114 // Timer for ms waits
00115     t.start();
00116      _slaveSelectPin = 1;
00117 
00118     // Setup the spi for 8 bit data : 1RW-bit 7 adressbit and  8 databit
00119     // second edge capture, with a 10MHz clock rate
00120     _spi.format(8,0);
00121     _spi.frequency(4000000);
00122 
00123 #define TIME_OUT 50
00124   
00125   start_to = t.read_ms() ;
00126 
00127   do writeReg(REG_SYNCVALUE1, 0xaa); while (readReg(REG_SYNCVALUE1) != 0xaa && t.read_ms()-start_to < TIME_OUT);
00128   if (t.read_ms()-start_to >= TIME_OUT) return (false);
00129     
00130   // Set time out 
00131   start_to = t.read_ms()  ;  
00132     do writeReg(REG_SYNCVALUE1, 0x55); while (readReg(REG_SYNCVALUE1) != 0x55 && t.read_ms()-start_to < TIME_OUT);
00133   if (t.read_ms()-start_to >= TIME_OUT) return (false);
00134   for (uint8_t i = 0; CONFIG[i][0] != 255; i++)
00135     writeReg(CONFIG[i][0], CONFIG[i][1]);
00136 
00137   // Encryption is persistent between resets and can trip you up during debugging.
00138   // Disable it during initialization so we always start from a known state.
00139   encrypt(0);
00140 
00141   setHighPower(_isRFM69HW); // called regardless if it's a RFM69W or RFM69HW
00142   setMode(RF69_MODE_STANDBY);
00143     // Set up interrupt handler
00144     start_to = t.read_ms() ;
00145     while (((readReg(REG_IRQFLAGS1) & RF_IRQFLAGS1_MODEREADY) == 0x00) && t.read_ms()-start_to < TIME_OUT); // Wait for ModeReady
00146   if (t.read_ms()-start_to >= TIME_OUT) return (false);
00147 
00148     _interrupt.rise(this, &RFM69::isr0);
00149  
00150   _address = nodeID;
00151    return true;
00152 }
00153 // return the frequency (in Hz)
00154 uint32_t RFM69::getFrequency()
00155 {
00156   return RF69_FSTEP * (((uint32_t) readReg(REG_FRFMSB) << 16) + ((uint16_t) readReg(REG_FRFMID) << 8) + readReg(REG_FRFLSB));
00157 }
00158 
00159 // set the frequency (in Hz)
00160 void RFM69::setFrequency(uint32_t freqHz)
00161 {
00162   uint8_t oldMode = _mode;
00163   if (oldMode == RF69_MODE_TX) {
00164     setMode(RF69_MODE_RX);
00165   }
00166   freqHz /= RF69_FSTEP; // divide down by FSTEP to get FRF
00167   writeReg(REG_FRFMSB, freqHz >> 16);
00168   writeReg(REG_FRFMID, freqHz >> 8);
00169   writeReg(REG_FRFLSB, freqHz);
00170   if (oldMode == RF69_MODE_RX) {
00171     setMode(RF69_MODE_SYNTH);
00172   }
00173   setMode(oldMode);
00174 }
00175 
00176 void RFM69::setMode(uint8_t newMode)
00177 {
00178   if (newMode == _mode)
00179     return;
00180 
00181   switch (newMode) {
00182     case RF69_MODE_TX:
00183       writeReg(REG_OPMODE, (readReg(REG_OPMODE) & 0xE3) | RF_OPMODE_TRANSMITTER);
00184       if (_isRFM69HW) setHighPowerRegs(true);
00185       break;
00186     case RF69_MODE_RX:
00187       writeReg(REG_OPMODE, (readReg(REG_OPMODE) & 0xE3) | RF_OPMODE_RECEIVER);
00188       if (_isRFM69HW) setHighPowerRegs(false);
00189       break;
00190     case RF69_MODE_SYNTH:
00191       writeReg(REG_OPMODE, (readReg(REG_OPMODE) & 0xE3) | RF_OPMODE_SYNTHESIZER);
00192       break;
00193     case RF69_MODE_STANDBY:
00194       writeReg(REG_OPMODE, (readReg(REG_OPMODE) & 0xE3) | RF_OPMODE_STANDBY);
00195       break;
00196     case RF69_MODE_SLEEP:
00197       writeReg(REG_OPMODE, (readReg(REG_OPMODE) & 0xE3) | RF_OPMODE_SLEEP);
00198       break;
00199     default:
00200       return;
00201   }
00202 
00203   // we are using packet mode, so this check is not really needed
00204   // but waiting for mode ready is necessary when going from sleep because the FIFO may not be immediately available from previous mode
00205   while (_mode == RF69_MODE_SLEEP && (readReg(REG_IRQFLAGS1) & RF_IRQFLAGS1_MODEREADY) == 0x00); // wait for ModeReady
00206   _mode = newMode;
00207 }
00208 
00209 void RFM69::sleep() {
00210   setMode(RF69_MODE_SLEEP);
00211 }
00212 
00213 void RFM69::setAddress(uint8_t addr)
00214 {
00215   _address = addr;
00216   writeReg(REG_NODEADRS, _address);
00217 }
00218 
00219 void RFM69::setNetwork(uint8_t networkID)
00220 {
00221   writeReg(REG_SYNCVALUE2, networkID);
00222 }
00223 
00224 // set output power: 0 = min, 31 = max
00225 // this results in a "weaker" transmitted signal, and directly results in a lower RSSI at the receiver
00226 void RFM69::setPowerLevel(uint8_t powerLevel)
00227 {
00228   _powerLevel = powerLevel;
00229   writeReg(REG_PALEVEL, (readReg(REG_PALEVEL) & 0xE0) | (_powerLevel > 31 ? 31 : _powerLevel));
00230 }
00231 
00232 bool RFM69::canSend()
00233 {
00234   if (_mode == RF69_MODE_RX && PAYLOADLEN == 0 && readRSSI() < CSMA_LIMIT) // if signal stronger than -100dBm is detected assume channel activity
00235   {
00236     setMode(RF69_MODE_STANDBY);
00237     return true;
00238   }
00239   return false;
00240 }
00241 
00242 void RFM69::send(uint8_t toAddress, const void* buffer, uint8_t bufferSize, bool requestACK)
00243 {
00244   writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFB) | RF_PACKET2_RXRESTART); // avoid RX deadlocks
00245   uint32_t now = t.read_ms();
00246   while (!canSend() && t.read_ms() - now < RF69_CSMA_LIMIT_MS) receiveDone();
00247   sendFrame(toAddress, buffer, bufferSize, requestACK, false);
00248 }
00249 
00250 // to increase the chance of getting a packet across, call this function instead of send
00251 // and it handles all the ACK requesting/retrying for you :)
00252 // The only twist is that you have to manually listen to ACK requests on the other side and send back the ACKs
00253 // The reason for the semi-automaton is that the lib is interrupt driven and
00254 // requires user action to read the received data and decide what to do with it
00255 // replies usually take only 5..8ms at 50kbps@915MHz
00256 bool RFM69::sendWithRetry(uint8_t toAddress, const void* buffer, uint8_t bufferSize, uint8_t retries, uint8_t retryWaitTime) {
00257   uint32_t sentTime;
00258   for (uint8_t i = 0; i <= retries; i++)
00259   {
00260     send(toAddress, buffer, bufferSize, true);
00261     sentTime = t.read_ms();
00262     while (t.read_ms() - sentTime < retryWaitTime)
00263     {
00264       if (ACKReceived(toAddress))
00265       {
00266         //Serial.print(" ~ms:"); Serial.print(t.read_ms() - sentTime);
00267         return true;
00268       }
00269     }
00270     //Serial.print(" RETRY#"); Serial.println(i + 1);
00271   }
00272   return false;
00273 }
00274 
00275 // should be polled immediately after sending a packet with ACK request
00276 bool RFM69::ACKReceived(uint8_t fromNodeID) {
00277   if (receiveDone())
00278     return (SENDERID == fromNodeID || fromNodeID == RF69_BROADCAST_ADDR) && ACK_RECEIVED;
00279   return false;
00280 }
00281 
00282 // check whether an ACK was requested in the last received packet (non-broadcasted packet)
00283 bool RFM69::ACKRequested() {
00284   return ACK_REQUESTED && (TARGETID != RF69_BROADCAST_ADDR);
00285 }
00286 
00287 // should be called immediately after reception in case sender wants ACK
00288 void RFM69::sendACK(const void* buffer, uint8_t bufferSize) {
00289   uint8_t sender = SENDERID;
00290   int16_t _RSSI = RSSI; // save payload received RSSI value
00291   writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFB) | RF_PACKET2_RXRESTART); // avoid RX deadlocks
00292   uint32_t now = t.read_ms();
00293   while (!canSend() && t.read_ms() - now < RF69_CSMA_LIMIT_MS) receiveDone();
00294   sendFrame(sender, buffer, bufferSize, false, true);
00295   RSSI = _RSSI; // restore payload RSSI
00296 }
00297 
00298 void RFM69::sendFrame(uint8_t toAddress, const void* buffer, uint8_t bufferSize, bool requestACK, bool sendACK)
00299 {
00300   setMode(RF69_MODE_STANDBY); // turn off receiver to prevent reception while filling fifo
00301   while ((readReg(REG_IRQFLAGS1) & RF_IRQFLAGS1_MODEREADY) == 0x00); // wait for ModeReady
00302   writeReg(REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_00); // DIO0 is "Packet Sent"
00303   if (bufferSize > RF69_MAX_DATA_LEN) bufferSize = RF69_MAX_DATA_LEN;
00304 
00305  // control byte
00306   uint8_t CTLbyte = 0x00;
00307   if (sendACK)
00308     CTLbyte = 0x80;
00309   else if (requestACK)
00310     CTLbyte = 0x40;
00311 
00312    select();
00313    _spi.write(REG_FIFO | 0x80); 
00314     _spi.write(bufferSize + 3);
00315    _spi.write(toAddress);
00316    _spi.write(_address);
00317    _spi.write(CTLbyte);
00318  
00319   for (uint8_t i = 0; i < bufferSize; i++)
00320      _spi.write(((uint8_t*) buffer)[i]);
00321   unselect();
00322 
00323   // no need to wait for transmit mode to be ready since its handled by the radio
00324   setMode(RF69_MODE_TX);
00325   uint32_t txStart = t.read_ms();
00326   while (_interrupt == 0 && t.read_ms() - txStart < RF69_TX_LIMIT_MS); // wait for DIO0 to turn HIGH signalling transmission finish
00327   //while (readReg(REG_IRQFLAGS2) & RF_IRQFLAGS2_PACKETSENT == 0x00); // wait for ModeReady
00328   setMode(RF69_MODE_STANDBY);
00329 }
00330 // ON  = disable filtering to capture all frames on network
00331 // OFF = enable node/broadcast filtering to capture only frames sent to this/broadcast address
00332 void RFM69::promiscuous(bool onOff) {
00333   _promiscuousMode = onOff;
00334   //writeReg(REG_PACKETCONFIG1, (readReg(REG_PACKETCONFIG1) & 0xF9) | (onOff ? RF_PACKET1_ADRSFILTERING_OFF : RF_PACKET1_ADRSFILTERING_NODEBROADCAST));
00335 }
00336 
00337 void RFM69::setHighPower(bool onOff) {
00338   _isRFM69HW = onOff;
00339   writeReg(REG_OCP, _isRFM69HW ? RF_OCP_OFF : RF_OCP_ON);
00340   if (_isRFM69HW) // turning ON
00341     writeReg(REG_PALEVEL, (readReg(REG_PALEVEL) & 0x1F) | RF_PALEVEL_PA1_ON | RF_PALEVEL_PA2_ON); // enable P1 & P2 amplifier stages
00342   else
00343     writeReg(REG_PALEVEL, RF_PALEVEL_PA0_ON | RF_PALEVEL_PA1_OFF | RF_PALEVEL_PA2_OFF | _powerLevel); // enable P0 only
00344 }
00345 
00346 void RFM69::setHighPowerRegs(bool onOff) {
00347   writeReg(REG_TESTPA1, onOff ? 0x5D : 0x55);
00348   writeReg(REG_TESTPA2, onOff ? 0x7C : 0x70);
00349 }
00350 
00351 /*
00352 void RFM69::setCS(uint8_t newSPISlaveSelect) {
00353     DigitalOut _slaveSelectPin(newSPISlaveSelect);
00354     _slaveSelectPin = 1;
00355 }
00356 */
00357 // for debugging
00358 void RFM69::readAllRegs()
00359 {
00360   uint8_t regVal,regAddr;
00361 
00362   for (regAddr = 1; regAddr <= 0x4F; regAddr++)
00363   {
00364     select();
00365     _spi.write(regAddr & 0x7F); // send address + r/w bit
00366     regVal = _spi.write(0);
00367  
00368  /*   Serial.print(regAddr, HEX);
00369     Serial.print(" - ");
00370     Serial.print(regVal,HEX);
00371     Serial.print(" - ");
00372     Serial.println(regVal,BIN);*/
00373   }
00374   unselect();
00375 }
00376 
00377 uint8_t RFM69::readTemperature(int8_t calFactor) // returns centigrade
00378 {
00379    uint8_t oldMode = _mode;
00380  
00381   setMode(RF69_MODE_STANDBY);
00382   writeReg(REG_TEMP1, RF_TEMP1_MEAS_START);
00383   while ((readReg(REG_TEMP1) & RF_TEMP1_MEAS_RUNNING));
00384   setMode(oldMode);
00385 
00386   return ~readReg(REG_TEMP2) + COURSE_TEMP_COEF + calFactor; // 'complement' corrects the slope, rising temp = rising val
00387 } // COURSE_TEMP_COEF puts reading in the ballpark, user can add additional correction
00388 
00389 void RFM69::rcCalibration()
00390 {
00391   writeReg(REG_OSC1, RF_OSC1_RCCAL_START);
00392   while ((readReg(REG_OSC1) & RF_OSC1_RCCAL_DONE) == 0x00);
00393 }
00394 // C++ level interrupt handler for this instance
00395 void RFM69::interruptHandler() {
00396 
00397   if (_mode == RF69_MODE_RX && (readReg(REG_IRQFLAGS2) & RF_IRQFLAGS2_PAYLOADREADY))
00398   {
00399     setMode(RF69_MODE_STANDBY);
00400     select();
00401 
00402     _spi.write(REG_FIFO & 0x7F);
00403     PAYLOADLEN = _spi.write(0);
00404     PAYLOADLEN = PAYLOADLEN > 66 ? 66 : PAYLOADLEN; // precaution
00405     TARGETID = _spi.write(0);
00406     if(!(_promiscuousMode || TARGETID == _address || TARGETID == RF69_BROADCAST_ADDR) // match this node's address, or broadcast address or anything in promiscuous mode
00407        || PAYLOADLEN < 3) // address situation could receive packets that are malformed and don't fit this libraries extra fields
00408     {
00409       PAYLOADLEN = 0;
00410       unselect();
00411       receiveBegin();
00412       return;
00413     }
00414 
00415     DATALEN = PAYLOADLEN - 3;
00416     SENDERID = _spi.write(0);
00417     uint8_t CTLbyte = _spi.write(0);
00418 
00419     ACK_RECEIVED = CTLbyte & 0x80; // extract ACK-received flag
00420     ACK_REQUESTED = CTLbyte & 0x40; // extract ACK-requested flag
00421 
00422     for (uint8_t i = 0; i < DATALEN; i++)
00423     {
00424       DATA[i] = _spi.write(0);
00425     }
00426     if (DATALEN < RF69_MAX_DATA_LEN) DATA[DATALEN] = 0; // add null at end of string
00427     unselect();
00428     setMode(RF69_MODE_RX);
00429   }
00430   RSSI = readRSSI();
00431 }
00432 
00433 
00434 // These are low level functions that call the interrupt handler for the correct instance of RFM69.
00435 void RFM69::isr0()
00436 {
00437      interruptHandler();
00438 }
00439 void RFM69::receiveBegin() {
00440   DATALEN = 0;
00441   SENDERID = 0;
00442   TARGETID = 0;
00443   PAYLOADLEN = 0;
00444   ACK_REQUESTED = 0;
00445   ACK_RECEIVED = 0;
00446   RSSI = 0;
00447   if (readReg(REG_IRQFLAGS2) & RF_IRQFLAGS2_PAYLOADREADY)
00448     writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFB) | RF_PACKET2_RXRESTART); // avoid RX deadlocks
00449   writeReg(REG_DIOMAPPING1, RF_DIOMAPPING1_DIO0_01); // set DIO0 to "PAYLOADREADY" in receive mode
00450   setMode(RF69_MODE_RX);
00451   _interrupt.enable_irq();
00452 }
00453 
00454 bool RFM69::receiveDone() {
00455   _interrupt.disable_irq();  // re-enabled in unselect() via setMode() or via receiveBegin()
00456   if (_mode == RF69_MODE_RX && PAYLOADLEN > 0)
00457   {
00458     setMode(RF69_MODE_STANDBY); // enables interrupts
00459     return true;
00460   }
00461   else if (_mode == RF69_MODE_RX) // already in RX no payload yet
00462   {
00463    _interrupt.enable_irq(); // explicitly re-enable interrupts
00464     return false;
00465   }
00466   receiveBegin();
00467   return false;
00468 }
00469 
00470 // To enable encryption: radio.encrypt("ABCDEFGHIJKLMNOP");
00471 // To disable encryption: radio.encrypt(null) or radio.encrypt(0)
00472 // KEY HAS TO BE 16 bytes !!!
00473 void RFM69::encrypt(const char* key) {
00474   setMode(RF69_MODE_STANDBY);
00475   if (key != 0)
00476   {
00477     select();
00478     _spi.write(REG_AESKEY1 | 0x80);
00479     for (uint8_t i = 0; i < 16; i++)
00480       _spi.write(key[i]);
00481     unselect();
00482   }
00483   writeReg(REG_PACKETCONFIG2, (readReg(REG_PACKETCONFIG2) & 0xFE) | (key ? 1 : 0));
00484 }
00485 
00486 int16_t RFM69::readRSSI(bool forceTrigger) {
00487   int16_t rssi = 0;
00488   if (forceTrigger)
00489   {
00490     // RSSI trigger not needed if DAGC is in continuous mode
00491     writeReg(REG_RSSICONFIG, RF_RSSI_START);
00492     while ((readReg(REG_RSSICONFIG) & RF_RSSI_DONE) == 0x00); // wait for RSSI_Ready
00493   }
00494   rssi = -readReg(REG_RSSIVALUE);
00495   rssi >>= 1;
00496   return rssi;
00497 }
00498 
00499 uint8_t RFM69::readReg(uint8_t addr)
00500 {
00501     select();
00502     _spi.write(addr & 0x7F); // Send the address with the write mask off
00503     uint8_t val = _spi.write(0); // The written value is ignored, reg value is read
00504     unselect();
00505     return val;
00506 }
00507 
00508 void RFM69::writeReg(uint8_t addr, uint8_t value)
00509 {
00510     select();
00511     _spi.write(addr | 0x80); // Send the address with the write mask on
00512     _spi.write(value); // New value follows
00513     unselect();
00514  }
00515 
00516 // select the transceiver
00517 void RFM69::select() {
00518    _interrupt.disable_irq();    // Disable Interrupts
00519 /*  // set RFM69 SPI settings
00520   SPI.setDataMode(SPI_MODE0);
00521   SPI.setBitOrder(MSBFIRST);
00522   SPI.setClockDivider(SPI_CLOCK_DIV4); // decided to slow down from DIV2 after SPI stalling in some instances, especially visible on mega1284p when RFM69 and FLASH chip both present  */
00523    _slaveSelectPin = 0;
00524 }
00525 
00526 // UNselect the transceiver chip
00527 void RFM69::unselect() {
00528     _slaveSelectPin = 1;
00529     _interrupt.enable_irq();     // Enable Interrupts
00530 }