]> oss.titaniummirror.com Git - tinyos-2.x.git/blobdiff - tos/chips/rf2xx/rf230/RF230DriverHwAckP.nc
Merge TinyOS 2.1.1 into master.
[tinyos-2.x.git] / tos / chips / rf2xx / rf230 / RF230DriverHwAckP.nc
diff --git a/tos/chips/rf2xx/rf230/RF230DriverHwAckP.nc b/tos/chips/rf2xx/rf230/RF230DriverHwAckP.nc
new file mode 100644 (file)
index 0000000..790e79e
--- /dev/null
@@ -0,0 +1,1019 @@
+/*
+* Copyright (c) 2009, University of Szeged
+* All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions
+* are met:
+*
+* - Redistributions of source code must retain the above copyright
+* notice, this list of conditions and the following disclaimer.
+* - Redistributions in binary form must reproduce the above
+* copyright notice, this list of conditions and the following
+* disclaimer in the documentation and/or other materials provided
+* with the distribution.
+* - Neither the name of University of Szeged nor the names of its
+* contributors may be used to endorse or promote products derived
+* from this software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+* OF THE POSSIBILITY OF SUCH DAMAGE.
+*
+* Author: Miklos Maroti
+*/
+
+#include <RF230DriverLayer.h>
+#include <Tasklet.h>
+#include <RadioAssert.h>
+#include <TimeSyncMessageLayer.h>
+#include <RadioConfig.h>
+
+module RF230DriverHwAckP
+{
+       provides
+       {
+               interface Init as PlatformInit @exactlyonce();
+               interface Init as SoftwareInit @exactlyonce();
+
+               interface RadioState;
+               interface RadioSend;
+               interface RadioReceive;
+               interface RadioCCA;
+               interface RadioPacket;
+
+               interface PacketField<uint8_t> as PacketTransmitPower;
+               interface PacketField<uint8_t> as PacketRSSI;
+               interface PacketField<uint8_t> as PacketTimeSyncOffset;
+               interface PacketField<uint8_t> as PacketLinkQuality;
+
+               interface PacketAcknowledgements;
+       }
+
+       uses
+       {
+               interface GeneralIO as SELN;
+               interface Resource as SpiResource;
+
+               interface FastSpiByte;
+
+               interface GeneralIO as SLP_TR;
+               interface GeneralIO as RSTN;
+
+               interface GpioCapture as IRQ;
+
+               interface BusyWait<TMicro, uint16_t>;
+               interface LocalTime<TRadio>;
+
+               interface RF230DriverConfig as Config;
+
+               interface PacketFlag as TransmitPowerFlag;
+               interface PacketFlag as RSSIFlag;
+               interface PacketFlag as TimeSyncFlag;
+
+               interface PacketTimeStamp<TRadio, uint32_t>;
+
+               interface Tasklet;
+               interface RadioAlarm;
+
+               interface PacketFlag as AckReceivedFlag;
+               interface Ieee154PacketLayer;
+               interface ActiveMessageAddress;
+
+#ifdef RADIO_DEBUG
+               interface DiagMsg;
+#endif
+       }
+}
+
+implementation
+{
+       rf230_header_t* getHeader(message_t* msg)
+       {
+               return ((void*)msg) + call Config.headerLength(msg);
+       }
+
+       void* getPayload(message_t* msg)
+       {
+               return ((void*)msg) + call RadioPacket.headerLength(msg);
+       }
+
+       rf230_metadata_t* getMeta(message_t* msg)
+       {
+               return ((void*)msg) + sizeof(message_t) - call RadioPacket.metadataLength(msg);
+       }
+
+/*----------------- STATE -----------------*/
+
+       tasklet_norace uint8_t state;
+       enum
+       {
+               STATE_P_ON = 0,
+               STATE_SLEEP = 1,
+               STATE_SLEEP_2_TRX_OFF = 2,
+               STATE_TRX_OFF = 3,
+               STATE_TRX_OFF_2_RX_ON = 4,
+               STATE_RX_ON = 5,
+               STATE_BUSY_TX_2_RX_ON = 6,
+       };
+
+       tasklet_norace uint8_t cmd;
+       enum
+       {
+               CMD_NONE = 0,                   // the state machine has stopped
+               CMD_TURNOFF = 1,                // goto SLEEP state
+               CMD_STANDBY = 2,                // goto TRX_OFF state
+               CMD_TURNON = 3,                 // goto RX_ON state
+               CMD_TRANSMIT = 4,               // currently transmitting a message
+               CMD_CCA = 6,                    // performing clear chanel assesment
+               CMD_CHANNEL = 7,                // changing the channel
+               CMD_SIGNAL_DONE = 8,            // signal the end of the state transition
+               CMD_DOWNLOAD = 9,               // download the received message
+       };
+
+       norace bool radioIrq;
+
+       tasklet_norace uint8_t txPower;
+       tasklet_norace uint8_t channel;
+
+       tasklet_norace message_t* rxMsg;
+       message_t rxMsgBuffer;
+
+       uint16_t capturedTime;  // the current time when the last interrupt has occured
+
+/*----------------- REGISTER -----------------*/
+
+       inline void writeRegister(uint8_t reg, uint8_t value)
+       {
+               ASSERT( call SpiResource.isOwner() );
+               ASSERT( reg == (reg & RF230_CMD_REGISTER_MASK) );
+
+               call SELN.clr();
+               call FastSpiByte.splitWrite(RF230_CMD_REGISTER_WRITE | reg);
+               call FastSpiByte.splitReadWrite(value);
+               call FastSpiByte.splitRead();
+               call SELN.set();
+       }
+
+       inline uint8_t readRegister(uint8_t reg)
+       {
+               ASSERT( call SpiResource.isOwner() );
+               ASSERT( reg == (reg & RF230_CMD_REGISTER_MASK) );
+
+               call SELN.clr();
+               call FastSpiByte.splitWrite(RF230_CMD_REGISTER_READ | reg);
+               call FastSpiByte.splitReadWrite(0);
+               reg = call FastSpiByte.splitRead();
+               call SELN.set();
+
+               return reg;
+       }
+
+/*----------------- ALARM -----------------*/
+
+       enum
+       {
+               SLEEP_WAKEUP_TIME = (uint16_t)(880 * RADIO_ALARM_MICROSEC),
+               PLL_CALIBRATION_TIME = (uint16_t)(180 * RADIO_ALARM_MICROSEC),
+               CCA_REQUEST_TIME = (uint16_t)(140 * RADIO_ALARM_MICROSEC),
+
+               // 8 undocumented delay, 128 for CSMA, 16 for delay, 5*32 for preamble and SFD
+               TX_SFD_DELAY = (uint16_t)((8 + 128 + 16 + 5*32) * RADIO_ALARM_MICROSEC),
+               
+               // 32 for frame length, 16 for delay
+               RX_SFD_DELAY = (uint16_t)((32 + 16) * RADIO_ALARM_MICROSEC),
+       };
+
+       tasklet_async event void RadioAlarm.fired()
+       {
+               if( state == STATE_SLEEP_2_TRX_OFF )
+                       state = STATE_TRX_OFF;
+               else if( state == STATE_TRX_OFF_2_RX_ON )
+               {
+                       ASSERT( cmd == CMD_TURNON || cmd == CMD_CHANNEL );
+
+                       state = STATE_RX_ON;
+                       cmd = CMD_SIGNAL_DONE;
+               }
+               else if( cmd == CMD_CCA )
+               {
+                       uint8_t cca;
+
+                       ASSERT( state == STATE_RX_ON );
+
+                       cmd = CMD_NONE;
+                       cca = readRegister(RF230_TRX_STATUS);
+
+                       ASSERT( (cca & RF230_TRX_STATUS_MASK) == RF230_RX_AACK_ON );
+
+                       signal RadioCCA.done( (cca & RF230_CCA_DONE) ? ((cca & RF230_CCA_STATUS) ? SUCCESS : EBUSY) : FAIL );
+               }
+               else
+                       ASSERT(FALSE);
+
+               // make sure the rest of the command processing is called
+               call Tasklet.schedule();
+       }
+
+/*----------------- INIT -----------------*/
+
+       command error_t PlatformInit.init()
+       {
+               call SELN.makeOutput();
+               call SELN.set();
+               call SLP_TR.makeOutput();
+               call SLP_TR.clr();
+               call RSTN.makeOutput();
+               call RSTN.set();
+
+               rxMsg = &rxMsgBuffer;
+
+               return SUCCESS;
+       }
+
+       command error_t SoftwareInit.init()
+       {
+               // for powering up the radio
+               return call SpiResource.request();
+       }
+
+       void initRadio()
+       {
+               uint16_t temp;
+
+               call BusyWait.wait(510);
+
+               call RSTN.clr();
+               call SLP_TR.clr();
+               call BusyWait.wait(6);
+               call RSTN.set();
+
+               writeRegister(RF230_TRX_CTRL_0, RF230_TRX_CTRL_0_VALUE);
+               writeRegister(RF230_TRX_STATE, RF230_TRX_OFF);
+
+               call BusyWait.wait(510);
+
+               writeRegister(RF230_IRQ_MASK, RF230_IRQ_TRX_UR | RF230_IRQ_TRX_END );
+               writeRegister(RF230_CCA_THRES, RF230_CCA_THRES_VALUE);
+               writeRegister(RF230_PHY_TX_PWR, RF230_TX_AUTO_CRC_ON | (RF230_DEF_RFPOWER & RF230_TX_PWR_MASK));
+
+               txPower = RF230_DEF_RFPOWER & RF230_TX_PWR_MASK;
+               channel = RF230_DEF_CHANNEL & RF230_CHANNEL_MASK;
+               writeRegister(RF230_PHY_CC_CCA, RF230_CCA_MODE_VALUE | channel);
+
+               writeRegister(RF230_XAH_CTRL, 0);
+               writeRegister(RF230_CSMA_SEED_1, 0);
+
+               temp = call ActiveMessageAddress.amGroup();
+               writeRegister(RF230_PAN_ID_0, temp);
+               writeRegister(RF230_PAN_ID_1, temp >> 8);
+
+               call SLP_TR.set();
+               state = STATE_SLEEP;
+       }
+
+/*----------------- SPI -----------------*/
+
+       event void SpiResource.granted()
+       {
+               call SELN.makeOutput();
+               call SELN.set();
+
+               if( state == STATE_P_ON )
+               {
+                       initRadio();
+                       call SpiResource.release();
+               }
+               else
+                       call Tasklet.schedule();
+       }
+
+       bool isSpiAcquired()
+       {
+               if( call SpiResource.isOwner() )
+                       return TRUE;
+
+               if( call SpiResource.immediateRequest() == SUCCESS )
+               {
+                       call SELN.makeOutput();
+                       call SELN.set();
+
+                       return TRUE;
+               }
+
+               call SpiResource.request();
+               return FALSE;
+       }
+
+/*----------------- CHANNEL -----------------*/
+
+tasklet_async command uint8_t RadioState.getChannel()
+       {
+               return channel;
+       }
+
+       tasklet_async command error_t RadioState.setChannel(uint8_t c)
+       {
+               c &= RF230_CHANNEL_MASK;
+
+               if( cmd != CMD_NONE )
+                       return EBUSY;
+               else if( channel == c )
+                       return EALREADY;
+
+               channel = c;
+               cmd = CMD_CHANNEL;
+               call Tasklet.schedule();
+
+               return SUCCESS;
+       }
+
+       inline void changeChannel()
+       {
+               ASSERT( cmd == CMD_CHANNEL );
+               ASSERT( state == STATE_SLEEP || state == STATE_TRX_OFF || state == STATE_RX_ON );
+
+               if( isSpiAcquired() && call RadioAlarm.isFree() )
+               {
+                       writeRegister(RF230_PHY_CC_CCA, RF230_CCA_MODE_VALUE | channel);
+
+                       if( state == STATE_RX_ON )
+                       {
+                               call RadioAlarm.wait(PLL_CALIBRATION_TIME);
+                               state = STATE_TRX_OFF_2_RX_ON;
+                       }
+                       else
+                               cmd = CMD_SIGNAL_DONE;
+               }
+       }
+
+/*----------------- TURN ON/OFF -----------------*/
+
+       inline void changeState()
+       {
+               if( (cmd == CMD_STANDBY || cmd == CMD_TURNON)
+                       && state == STATE_SLEEP && call RadioAlarm.isFree() )
+               {
+                       call SLP_TR.clr();
+
+                       call RadioAlarm.wait(SLEEP_WAKEUP_TIME);
+                       state = STATE_SLEEP_2_TRX_OFF;
+               }
+               else if( cmd == CMD_TURNON && state == STATE_TRX_OFF 
+                       && isSpiAcquired() && call RadioAlarm.isFree() )
+               {
+                       uint16_t temp;
+       
+                       ASSERT( ! radioIrq );
+
+                       readRegister(RF230_IRQ_STATUS); // clear the interrupt register
+                       call IRQ.captureRisingEdge();
+
+                       // setChannel was ignored in SLEEP because the SPI was not working, so do it here
+                       writeRegister(RF230_PHY_CC_CCA, RF230_CCA_MODE_VALUE | channel);
+
+                       temp = call ActiveMessageAddress.amAddress();
+                       writeRegister(RF230_SHORT_ADDR_0, temp);
+                       writeRegister(RF230_SHORT_ADDR_1, temp >> 8);
+
+                       call RadioAlarm.wait(PLL_CALIBRATION_TIME);
+                       writeRegister(RF230_TRX_STATE, RF230_RX_AACK_ON);
+                       state = STATE_TRX_OFF_2_RX_ON;
+               }
+               else if( (cmd == CMD_TURNOFF || cmd == CMD_STANDBY) 
+                       && state == STATE_RX_ON && isSpiAcquired() )
+               {
+                       writeRegister(RF230_TRX_STATE, RF230_FORCE_TRX_OFF);
+
+                       call IRQ.disable();
+                       radioIrq = FALSE;
+
+                       state = STATE_TRX_OFF;
+               }
+
+               if( cmd == CMD_TURNOFF && state == STATE_TRX_OFF )
+               {
+                       call SLP_TR.set();
+                       state = STATE_SLEEP;
+                       cmd = CMD_SIGNAL_DONE;
+               }
+               else if( cmd == CMD_STANDBY && state == STATE_TRX_OFF )
+                       cmd = CMD_SIGNAL_DONE;
+       }
+
+       tasklet_async command error_t RadioState.turnOff()
+       {
+               if( cmd != CMD_NONE )
+                       return EBUSY;
+               else if( state == STATE_SLEEP )
+                       return EALREADY;
+
+               cmd = CMD_TURNOFF;
+               call Tasklet.schedule();
+
+               return SUCCESS;
+       }
+       
+       tasklet_async command error_t RadioState.standby()
+       {
+               if( cmd != CMD_NONE || (state == STATE_SLEEP && ! call RadioAlarm.isFree()) )
+                       return EBUSY;
+               else if( state == STATE_TRX_OFF )
+                       return EALREADY;
+
+               cmd = CMD_STANDBY;
+               call Tasklet.schedule();
+
+               return SUCCESS;
+       }
+
+       tasklet_async command error_t RadioState.turnOn()
+       {
+               if( cmd != CMD_NONE || (state == STATE_SLEEP && ! call RadioAlarm.isFree()) )
+                       return EBUSY;
+               else if( state == STATE_RX_ON )
+                       return EALREADY;
+
+               cmd = CMD_TURNON;
+               call Tasklet.schedule();
+
+               return SUCCESS;
+       }
+
+       default tasklet_async event void RadioState.done() { }
+
+       task void changeAddress()
+       {
+               call Tasklet.suspend();
+
+               if( isSpiAcquired() )
+               {
+                       uint16_t temp = call ActiveMessageAddress.amAddress();
+                       writeRegister(RF230_SHORT_ADDR_0, temp);
+                       writeRegister(RF230_SHORT_ADDR_1, temp >> 8);
+               }
+               else
+                       post changeAddress();
+
+               call Tasklet.resume();
+       }
+
+       async event void ActiveMessageAddress.changed()
+       {
+               post changeAddress();
+       }
+
+/*----------------- TRANSMIT -----------------*/
+
+       tasklet_norace message_t* txMsg;
+
+       tasklet_async command error_t RadioSend.send(message_t* msg)
+       {
+               uint16_t time;
+               uint8_t length;
+               uint8_t* data;
+               uint8_t header;
+               uint32_t time32;
+               void* timesync;
+
+               if( cmd != CMD_NONE || state != STATE_RX_ON || ! isSpiAcquired() || radioIrq )
+                       return EBUSY;
+
+               length = (call PacketTransmitPower.isSet(msg) ?
+                       call PacketTransmitPower.get(msg) : RF230_DEF_RFPOWER) & RF230_TX_PWR_MASK;
+
+               if( length != txPower )
+               {
+                       txPower = length;
+                       writeRegister(RF230_PHY_TX_PWR, RF230_TX_AUTO_CRC_ON | txPower);
+               }
+
+               writeRegister(RF230_TRX_STATE, RF230_TX_ARET_ON);
+
+               // do something useful, just to wait a little
+               time32 = call LocalTime.get();
+               timesync = call PacketTimeSyncOffset.isSet(msg) ? ((void*)msg) + call PacketTimeSyncOffset.get(msg) : 0;
+
+               // we have missed an incoming message in this short amount of time
+               if( (readRegister(RF230_TRX_STATUS) & RF230_TRX_STATUS_MASK) != RF230_TX_ARET_ON )
+               {
+                       ASSERT( (readRegister(RF230_TRX_STATUS) & RF230_TRX_STATUS_MASK) == RF230_BUSY_RX_AACK );
+
+                       writeRegister(RF230_TRX_STATE, RF230_RX_AACK_ON);
+                       return EBUSY;
+               }
+
+#ifndef RF230_SLOW_SPI
+               atomic
+               {
+                       call SLP_TR.set();
+                       time = call RadioAlarm.getNow();
+               }
+               call SLP_TR.clr();
+#endif
+
+               ASSERT( ! radioIrq );
+
+               call SELN.clr();
+               call FastSpiByte.splitWrite(RF230_CMD_FRAME_WRITE);
+
+               data = getPayload(msg);
+               length = getHeader(msg)->length;
+
+               // length | data[0] ... data[length-3] | automatically generated FCS
+               call FastSpiByte.splitReadWrite(length);
+
+               // the FCS is atomatically generated (2 bytes)
+               length -= 2;
+
+               header = call Config.headerPreloadLength();
+               if( header > length )
+                       header = length;
+
+               length -= header;
+
+               // first upload the header to gain some time
+               do {
+                       call FastSpiByte.splitReadWrite(*(data++));
+               }
+               while( --header != 0 );
+
+#ifdef RF230_SLOW_SPI
+               atomic
+               {
+                       call SLP_TR.set();
+                       time = call RadioAlarm.getNow();
+               }
+               call SLP_TR.clr();
+#endif
+
+               time32 += (int16_t)(time + TX_SFD_DELAY) - (int16_t)(time32);
+
+               if( timesync != 0 )
+                       *(timesync_relative_t*)timesync = (*(timesync_absolute_t*)timesync) - time32;
+
+               while( length-- != 0 )
+                       call FastSpiByte.splitReadWrite(*(data++));
+
+               // wait for the SPI transfer to finish
+               call FastSpiByte.splitRead();
+               call SELN.set();
+
+               /*
+                * There is a very small window (~1 microsecond) when the RF230 went 
+                * into PLL_ON state but was somehow not properly initialized because 
+                * of an incoming message and could not go into BUSY_TX. I think the
+                * radio can even receive a message, and generate a TRX_UR interrupt
+                * because of concurrent access, but that message probably cannot be
+                * recovered.
+                *
+                * TODO: this needs to be verified, and make sure that the chip is 
+                * not locked up in this case.
+                */
+
+               // go back to RX_ON state when finished
+               writeRegister(RF230_TRX_STATE, RF230_RX_AACK_ON);
+
+               if( timesync != 0 )
+                       *(timesync_absolute_t*)timesync = (*(timesync_relative_t*)timesync) + time32;
+
+               call PacketTimeStamp.set(msg, time32);
+
+#ifdef RADIO_DEBUG_MESSAGES
+               if( call DiagMsg.record() )
+               {
+                       length = getHeader(msg)->length;
+
+                       call DiagMsg.chr('t');
+                       call DiagMsg.uint32(call PacketTimeStamp.isValid(rxMsg) ? call PacketTimeStamp.timestamp(rxMsg) : 0);
+                       call DiagMsg.uint16(call RadioAlarm.getNow());
+                       call DiagMsg.int8(length);
+                       call DiagMsg.hex8s(getPayload(msg), length - 2);
+                       call DiagMsg.send();
+               }
+#endif
+
+               // wait for the TRX_END interrupt
+               txMsg = msg;
+               state = STATE_BUSY_TX_2_RX_ON;
+               cmd = CMD_TRANSMIT;
+
+               return SUCCESS;
+       }
+
+       default tasklet_async event void RadioSend.sendDone(error_t error) { }
+       default tasklet_async event void RadioSend.ready() { }
+
+/*----------------- CCA -----------------*/
+
+       tasklet_async command error_t RadioCCA.request()
+       {
+               if( cmd != CMD_NONE || state != STATE_RX_ON || ! isSpiAcquired() || ! call RadioAlarm.isFree() )
+                       return EBUSY;
+
+               // see Errata B7 of the datasheet
+               // writeRegister(RF230_TRX_STATE, RF230_PLL_ON);
+               // writeRegister(RF230_TRX_STATE, RF230_RX_AACK_ON);
+
+               writeRegister(RF230_PHY_CC_CCA, RF230_CCA_REQUEST | RF230_CCA_MODE_VALUE | channel);
+               call RadioAlarm.wait(CCA_REQUEST_TIME);
+               cmd = CMD_CCA;
+               
+               return SUCCESS;
+       }
+
+       default tasklet_async event void RadioCCA.done(error_t error) { }
+
+/*----------------- RECEIVE -----------------*/
+
+       inline void downloadMessage()
+       {
+               uint8_t length;
+               bool crcValid = FALSE;
+
+               call SELN.clr();
+               call FastSpiByte.write(RF230_CMD_FRAME_READ);
+
+               // read the length byte
+               length = call FastSpiByte.write(0);
+
+               // if correct length
+               if( length >= 3 && length <= call RadioPacket.maxPayloadLength() + 2 )
+               {
+                       uint8_t read;
+                       uint8_t* data;
+
+                       // initiate the reading
+                       call FastSpiByte.splitWrite(0);
+
+                       data = getPayload(rxMsg);
+                       getHeader(rxMsg)->length = length;
+
+                       // we do not store the CRC field
+                       length -= 2;
+
+                       read = call Config.headerPreloadLength();
+                       if( length < read )
+                               read = length;
+
+                       length -= read;
+
+                       do {
+                               *(data++) = call FastSpiByte.splitReadWrite(0);
+                       }
+                       while( --read != 0  );
+
+                       if( signal RadioReceive.header(rxMsg) )
+                       {
+                               while( length-- != 0 )
+                                       *(data++) = call FastSpiByte.splitReadWrite(0);
+
+                               call FastSpiByte.splitReadWrite(0);     // two CRC bytes
+                               call FastSpiByte.splitReadWrite(0);
+
+                               call PacketLinkQuality.set(rxMsg, call FastSpiByte.splitRead());
+
+                               // we should have no other incoming message or buffer underflow
+                               crcValid = ! radioIrq;
+                       }
+               }
+
+               call SELN.set();
+
+               if( crcValid && call PacketTimeStamp.isValid(rxMsg) )
+               {
+                       uint32_t time32 = call PacketTimeStamp.timestamp(rxMsg);
+                       length = getHeader(rxMsg)->length;
+
+/*
+ * If you hate floating point arithmetics and do not care of up to 400 microsecond time stamping errors,
+ * then define RF230_HWACK_SLOPPY_TIMESTAMP, which will be significantly faster.
+ */
+#ifdef RF230_HWACK_SLOPPY_TIMESTAMP
+                       time32 -= (uint16_t)(RX_SFD_DELAY) + ((uint16_t)(length) << (RADIO_ALARM_MILLI_EXP - 5));
+#else
+                       time32 -= (uint16_t)(RX_SFD_DELAY) + (uint16_t)(32.0 * RADIO_ALARM_MICROSEC * (uint16_t)length);
+#endif
+
+                       call PacketTimeStamp.set(rxMsg, time32);
+               }
+
+#ifdef RADIO_DEBUG_MESSAGES
+               if( call DiagMsg.record() )
+               {
+                       length = getHeader(rxMsg)->length;
+
+                       call DiagMsg.chr('r');
+                       call DiagMsg.uint32(call PacketTimeStamp.isValid(rxMsg) ? call PacketTimeStamp.timestamp(rxMsg) : 0);
+                       call DiagMsg.uint16(call RadioAlarm.getNow());
+                       call DiagMsg.int8(crcValid ? length : -length);
+                       call DiagMsg.hex8s(getPayload(rxMsg), length - 2);
+                       call DiagMsg.int8(call PacketRSSI.isSet(rxMsg) ? call PacketRSSI.get(rxMsg) : -1);
+                       call DiagMsg.uint8(call PacketLinkQuality.isSet(rxMsg) ? call PacketLinkQuality.get(rxMsg) : 0);
+                       call DiagMsg.send();
+               }
+#endif
+
+               state = STATE_RX_ON;
+               cmd = CMD_NONE;
+
+               // signal only if it has passed the CRC check
+               if( crcValid )
+                       rxMsg = signal RadioReceive.receive(rxMsg);
+       }
+
+/*----------------- IRQ -----------------*/
+
+       async event void IRQ.captured(uint16_t time)
+       {
+               ASSERT( ! radioIrq );
+
+               atomic
+               {
+                       capturedTime = time;
+                       radioIrq = TRUE;
+               }
+
+               call Tasklet.schedule();
+       }
+
+       void serviceRadio()
+       {
+               if( isSpiAcquired() )
+               {
+                       uint16_t time;
+                       uint32_t time32;
+                       uint8_t irq;
+                       uint8_t temp;
+                       
+                       atomic time = capturedTime;
+                       radioIrq = FALSE;
+                       irq = readRegister(RF230_IRQ_STATUS);
+
+#ifdef RADIO_DEBUG
+                       // TODO: handle this interrupt
+                       if( irq & RF230_IRQ_TRX_UR )
+                       {
+                               if( call DiagMsg.record() )
+                               {
+                                       call DiagMsg.str("assert ur");
+                                       call DiagMsg.uint16(call RadioAlarm.getNow());
+                                       call DiagMsg.hex8(readRegister(RF230_TRX_STATUS));
+                                       call DiagMsg.hex8(readRegister(RF230_TRX_STATE));
+                                       call DiagMsg.hex8(irq);
+                                       call DiagMsg.uint8(state);
+                                       call DiagMsg.uint8(cmd);
+                                       call DiagMsg.send();
+                               }
+                       }
+#endif
+
+                       if( irq & RF230_IRQ_TRX_END )
+                       {
+                               if( cmd == CMD_TRANSMIT )
+                               {
+                                       ASSERT( state == STATE_BUSY_TX_2_RX_ON );
+
+                                       temp = readRegister(RF230_TRX_STATE) & RF230_TRAC_STATUS_MASK;
+
+                                       if( call Ieee154PacketLayer.getAckRequired(txMsg) )
+                                               call AckReceivedFlag.setValue(txMsg, temp != RF230_TRAC_NO_ACK);
+
+                                       state = STATE_RX_ON;
+                                       cmd = CMD_NONE;
+
+                                       signal RadioSend.sendDone(temp != RF230_TRAC_CHANNEL_ACCESS_FAILURE ? SUCCESS : EBUSY);
+
+                                       // TODO: we could have missed a received message
+                                       ASSERT( ! (irq & RF230_IRQ_RX_START) );
+                               }
+                               else if( cmd == CMD_NONE )
+                               {
+                                       ASSERT( state == STATE_RX_ON );
+
+                                       if( irq == RF230_IRQ_TRX_END )
+                                       {
+                                               call PacketRSSI.set(rxMsg, readRegister(RF230_PHY_ED_LEVEL));
+
+                                               // TODO: compensate for packet transmission time when downloading
+                                               time32 = call LocalTime.get();
+                                               time32 += (int16_t)(time) - (int16_t)(time32);
+                                               call PacketTimeStamp.set(rxMsg, time32);
+                                       }
+                                       else
+                                       {
+                                               call PacketRSSI.clear(rxMsg);
+                                               call PacketTimeStamp.clear(rxMsg);
+                                       }
+
+                                       cmd = CMD_DOWNLOAD;
+                               }
+                               else
+                                       ASSERT(FALSE);
+                       }
+               }
+       }
+
+       default tasklet_async event bool RadioReceive.header(message_t* msg)
+       {
+               return TRUE;
+       }
+
+       default tasklet_async event message_t* RadioReceive.receive(message_t* msg)
+       {
+               return msg;
+       }
+
+/*----------------- TASKLET -----------------*/
+
+       tasklet_async event void Tasklet.run()
+       {
+               if( radioIrq )
+                       serviceRadio();
+
+               if( cmd != CMD_NONE )
+               {
+                       if( cmd == CMD_DOWNLOAD )
+                               downloadMessage();
+                       else if( CMD_TURNOFF <= cmd && cmd <= CMD_TURNON )
+                               changeState();
+                       else if( cmd == CMD_CHANNEL )
+                               changeChannel();
+                       
+                       if( cmd == CMD_SIGNAL_DONE )
+                       {
+                               cmd = CMD_NONE;
+                               signal RadioState.done();
+                       }
+               }
+
+               if( cmd == CMD_NONE && state == STATE_RX_ON && ! radioIrq )
+                       signal RadioSend.ready();
+
+               if( cmd == CMD_NONE )
+                       call SpiResource.release();
+       }
+
+/*----------------- RadioPacket -----------------*/
+       
+       async command uint8_t RadioPacket.headerLength(message_t* msg)
+       {
+               return call Config.headerLength(msg) + sizeof(rf230_header_t);
+       }
+
+       async command uint8_t RadioPacket.payloadLength(message_t* msg)
+       {
+               return getHeader(msg)->length - 2;
+       }
+
+       async command void RadioPacket.setPayloadLength(message_t* msg, uint8_t length)
+       {
+               ASSERT( 1 <= length && length <= 125 );
+               ASSERT( call RadioPacket.headerLength(msg) + length + call RadioPacket.metadataLength(msg) <= sizeof(message_t) );
+
+               // we add the length of the CRC, which is automatically generated
+               getHeader(msg)->length = length + 2;
+       }
+
+       async command uint8_t RadioPacket.maxPayloadLength()
+       {
+               ASSERT( call Config.maxPayloadLength() <= 125 );
+
+               return call Config.maxPayloadLength() - sizeof(rf230_header_t);
+       }
+
+       async command uint8_t RadioPacket.metadataLength(message_t* msg)
+       {
+               return call Config.metadataLength(msg) + sizeof(rf230_metadata_t);
+       }
+
+       async command void RadioPacket.clear(message_t* msg)
+       {
+               // all flags are automatically cleared
+       }
+
+/*----------------- PacketTransmitPower -----------------*/
+
+       async command bool PacketTransmitPower.isSet(message_t* msg)
+       {
+               return call TransmitPowerFlag.get(msg);
+       }
+
+       async command uint8_t PacketTransmitPower.get(message_t* msg)
+       {
+               return getMeta(msg)->power;
+       }
+
+       async command void PacketTransmitPower.clear(message_t* msg)
+       {
+               call TransmitPowerFlag.clear(msg);
+       }
+
+       async command void PacketTransmitPower.set(message_t* msg, uint8_t value)
+       {
+               call TransmitPowerFlag.set(msg);
+               getMeta(msg)->power = value;
+       }
+
+/*----------------- PacketRSSI -----------------*/
+
+       async command bool PacketRSSI.isSet(message_t* msg)
+       {
+               return call RSSIFlag.get(msg);
+       }
+
+       async command uint8_t PacketRSSI.get(message_t* msg)
+       {
+               return getMeta(msg)->rssi;
+       }
+
+       async command void PacketRSSI.clear(message_t* msg)
+       {
+               call RSSIFlag.clear(msg);
+       }
+
+       async command void PacketRSSI.set(message_t* msg, uint8_t value)
+       {
+               // just to be safe if the user fails to clear the packet
+               call TransmitPowerFlag.clear(msg);
+
+               call RSSIFlag.set(msg);
+               getMeta(msg)->rssi = value;
+       }
+
+/*----------------- PacketTimeSyncOffset -----------------*/
+
+       async command bool PacketTimeSyncOffset.isSet(message_t* msg)
+       {
+               return call TimeSyncFlag.get(msg);
+       }
+
+       async command uint8_t PacketTimeSyncOffset.get(message_t* msg)
+       {
+               return call RadioPacket.headerLength(msg) + call RadioPacket.payloadLength(msg) - sizeof(timesync_absolute_t);
+       }
+
+       async command void PacketTimeSyncOffset.clear(message_t* msg)
+       {
+               call TimeSyncFlag.clear(msg);
+       }
+
+       async command void PacketTimeSyncOffset.set(message_t* msg, uint8_t value)
+       {
+               // we do not store the value, the time sync field is always the last 4 bytes
+               ASSERT( call PacketTimeSyncOffset.get(msg) == value );
+
+               call TimeSyncFlag.set(msg);
+       }
+
+/*----------------- PacketLinkQuality -----------------*/
+
+       async command bool PacketLinkQuality.isSet(message_t* msg)
+       {
+               return TRUE;
+       }
+
+       async command uint8_t PacketLinkQuality.get(message_t* msg)
+       {
+               return getMeta(msg)->lqi;
+       }
+
+       async command void PacketLinkQuality.clear(message_t* msg)
+       {
+       }
+
+       async command void PacketLinkQuality.set(message_t* msg, uint8_t value)
+       {
+               getMeta(msg)->lqi = value;
+       }
+
+/*----------------- PacketAcknowledgements -----------------*/
+
+       async command error_t PacketAcknowledgements.requestAck(message_t* msg)
+       {
+               call Ieee154PacketLayer.setAckRequired(msg, TRUE);
+
+               return SUCCESS;
+       }
+
+       async command error_t PacketAcknowledgements.noAck(message_t* msg)
+       {
+               call Ieee154PacketLayer.setAckRequired(msg, FALSE);
+
+               return SUCCESS;
+       }
+
+       async command bool PacketAcknowledgements.wasAcked(message_t* msg)
+       {
+               return call AckReceivedFlag.get(msg);
+       }
+}