Revision 0:8ae48233b4e4, committed 2011-01-19

Comitter:

Owen

Date:

Wed Jan 19 22:59:48 2011 +0000

Commit message:

Initial (working, TX and RX) version.
No support for interrupts, Auto Retransmit, Auto Acknowledge, Dynamic Payload length or ShockBurst/Enhanced ShockBurst.

Changed in this revision

diff -r 000000000000 -r 8ae48233b4e4 nRF24L01P.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF24L01P.cpp	Wed Jan 19 22:59:48 2011 +0000
@@ -0,0 +1,1029 @@
+/**
+ * @file nRF24L01P.cpp
+ *
+ * @author Owen Edwards
+ * 
+ * @section LICENSE
+ *
+ * Copyright (c) 2010 Owen Edwards
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * @section DESCRIPTION
+ *
+ * nRF24L01+ Single Chip 2.4GHz Transceiver from Nordic Semiconductor.
+ *
+ * Datasheet:
+ *
+ * http://www.nordicsemi.no/files/Product/data_sheet/nRF24L01P_Product_Specification_1_0.pdf
+ */
+
+/**
+ * Includes
+ */
+#include "nRF24L01P.h"
+
+/**
+ * Defines
+ *
+ * (Note that all defines here start with an underscore, e.g. '_NRF24L01P_MODE_UNKNOWN',
+ *  and are local to this library.  The defines in the nRF24L01P.h file do not start
+ *  with the underscore, and can be used by code to access this library.)
+ */
+
+typedef enum {
+    _NRF24L01P_MODE_UNKNOWN,
+    _NRF24L01P_MODE_POWER_DOWN,
+    _NRF24L01P_MODE_STANDBY,
+    _NRF24L01P_MODE_RX,
+    _NRF24L01P_MODE_TX,
+} nRF24L01P_Mode_Type;
+
+/*
+ * The following FIFOs are present in nRF24L01+:
+ *   TX three level, 32 byte FIFO
+ *   RX three level, 32 byte FIFO
+ */
+#define _NRF24L01P_TX_FIFO_COUNT   3
+#define _NRF24L01P_RX_FIFO_COUNT   3
+
+#define _NRF24L01P_TX_FIFO_SIZE   32
+#define _NRF24L01P_RX_FIFO_SIZE   32
+
+#define _NRF24L01P_SPI_MAX_DATA_RATE     10000000
+
+#define _NRF24L01P_SPI_CMD_RD_REG            0x00
+#define _NRF24L01P_SPI_CMD_WR_REG            0x20
+#define _NRF24L01P_SPI_CMD_RD_RX_PAYLOAD     0x61   
+#define _NRF24L01P_SPI_CMD_WR_TX_PAYLOAD     0xa0
+#define _NRF24L01P_SPI_CMD_FLUSH_TX          0xe1
+#define _NRF24L01P_SPI_CMD_FLUSH_RX          0xe2
+#define _NRF24L01P_SPI_CMD_REUSE_TX_PL       0xe3
+#define _NRF24L01P_SPI_CMD_R_RX_PL_WID       0x60
+#define _NRF24L01P_SPI_CMD_W_ACK_PAYLOAD     0xa8
+#define _NRF24L01P_SPI_CMD_W_TX_PYLD_NO_ACK  0xb0
+#define _NRF24L01P_SPI_CMD_NOP               0xff
+
+
+#define _NRF24L01P_REG_CONFIG                0x00
+#define _NRF24L01P_REG_EN_AA                 0x01
+#define _NRF24L01P_REG_EN_RXADDR             0x02
+#define _NRF24L01P_REG_SETUP_AW              0x03
+#define _NRF24L01P_REG_SETUP_RETR            0x04
+#define _NRF24L01P_REG_RF_CH                 0x05
+#define _NRF24L01P_REG_RF_SETUP              0x06
+#define _NRF24L01P_REG_STATUS                0x07
+#define _NRF24L01P_REG_OBSERVE_TX            0x08
+#define _NRF24L01P_REG_RPD                   0x09
+#define _NRF24L01P_REG_RX_ADDR_P0            0x0a
+#define _NRF24L01P_REG_RX_ADDR_P1            0x0b
+#define _NRF24L01P_REG_RX_ADDR_P2            0x0c
+#define _NRF24L01P_REG_RX_ADDR_P3            0x0d
+#define _NRF24L01P_REG_RX_ADDR_P4            0x0e
+#define _NRF24L01P_REG_RX_ADDR_P5            0x0f
+#define _NRF24L01P_REG_TX_ADDR               0x10
+#define _NRF24L01P_REG_RX_PW_P0              0x11
+#define _NRF24L01P_REG_RX_PW_P1              0x12
+#define _NRF24L01P_REG_RX_PW_P2              0x13
+#define _NRF24L01P_REG_RX_PW_P3              0x14
+#define _NRF24L01P_REG_RX_PW_P4              0x15
+#define _NRF24L01P_REG_RX_PW_P5              0x16
+#define _NRF24L01P_REG_FIFO_STATUS           0x17
+#define _NRF24L01P_REG_DYNPD                 0x1c
+#define _NRF24L01P_REG_FEATURE               0x1d
+
+#define _NRF24L01P_REG_ADDRESS_MASK          0x1f
+
+// CONFIG register:
+#define _NRF24L01P_CONFIG_PRIM_RX        (1<<0)
+#define _NRF24L01P_CONFIG_PWR_UP         (1<<1)
+#define _NRF24L01P_CONFIG_CRC0           (1<<2)
+#define _NRF24L01P_CONFIG_EN_CRC         (1<<3)
+#define _NRF24L01P_CONFIG_MASK_MAX_RT    (1<<4)
+#define _NRF24L01P_CONFIG_MASK_TX_DS     (1<<5)
+#define _NRF24L01P_CONFIG_MASK_RX_DR     (1<<6)
+
+#define _NRF24L01P_CONFIG_CRC_MASK       (_NRF24L01P_CONFIG_EN_CRC|_NRF24L01P_CONFIG_CRC0)
+#define _NRF24L01P_CONFIG_CRC_NONE       (0)
+#define _NRF24L01P_CONFIG_CRC_8BIT       (_NRF24L01P_CONFIG_EN_CRC)
+#define _NRF24L01P_CONFIG_CRC_16BIT      (_NRF24L01P_CONFIG_EN_CRC|_NRF24L01P_CONFIG_CRC0)
+
+// EN_AA register:
+#define _NRF24L01P_EN_AA_NONE            0
+
+// EN_RXADDR register:
+#define _NRF24L01P_EN_RXADDR_NONE        0
+
+// SETUP_AW register:
+#define _NRF24L01P_SETUP_AW_AW_MASK      (0x3<<0)
+#define _NRF24L01P_SETUP_AW_AW_3BYTE     (0x1<<0)
+#define _NRF24L01P_SETUP_AW_AW_4BYTE     (0x2<<0)
+#define _NRF24L01P_SETUP_AW_AW_5BYTE     (0x3<<0)
+
+// SETUP_RETR register:
+#define _NRF24L01P_SETUP_RETR_NONE       0
+
+// RF_SETUP register:
+#define _NRF24L01P_RF_SETUP_RF_PWR_MASK          (0x3<<1)
+#define _NRF24L01P_RF_SETUP_RF_PWR_0DBM          (0x3<<1)
+#define _NRF24L01P_RF_SETUP_RF_PWR_MINUS_6DBM    (0x2<<1)
+#define _NRF24L01P_RF_SETUP_RF_PWR_MINUS_12DBM   (0x1<<1)
+#define _NRF24L01P_RF_SETUP_RF_PWR_MINUS_18DBM   (0x0<<1)
+
+#define _NRF24L01P_RF_SETUP_RF_DR_HIGH_BIT       (1 << 3)
+#define _NRF24L01P_RF_SETUP_RF_DR_LOW_BIT        (1 << 5)
+#define _NRF24L01P_RF_SETUP_RF_DR_MASK           (_NRF24L01P_RF_SETUP_RF_DR_LOW_BIT|_NRF24L01P_RF_SETUP_RF_DR_HIGH_BIT)
+#define _NRF24L01P_RF_SETUP_RF_DR_250KBPS        (_NRF24L01P_RF_SETUP_RF_DR_LOW_BIT)
+#define _NRF24L01P_RF_SETUP_RF_DR_1MBPS          (0)
+#define _NRF24L01P_RF_SETUP_RF_DR_2MBPS          (_NRF24L01P_RF_SETUP_RF_DR_HIGH_BIT)
+
+// STATUS register:
+#define _NRF24L01P_STATUS_TX_FULL        (1<<0)
+#define _NRF24L01P_STATUS_RX_P_NO        (0x7<<1)
+#define _NRF24L01P_STATUS_MAX_RT         (1<<4)
+#define _NRF24L01P_STATUS_TX_DS          (1<<5)
+#define _NRF24L01P_STATUS_RX_DR          (1<<6)
+
+// RX_PW_P0..RX_PW_P5 registers:
+#define _NRF24L01P_RX_PW_Px_MASK         0x3F
+
+#define _NRF24L01P_TIMING_Tundef2pd_us     100000   // 100mS
+#define _NRF24L01P_TIMING_Tstby2a_us          130   // 130uS
+#define _NRF24L01P_TIMING_Thce_us              10   //  10uS
+#define _NRF24L01P_TIMING_Tpd2stby_us        4500   // 4.5mS worst case
+#define _NRF24L01P_TIMING_Tpece2csn_us          4   //   4uS
+
+/**
+ * Methods
+ */
+
+nRF24L01P::nRF24L01P(PinName mosi, 
+                     PinName miso, 
+                     PinName sck, 
+                     PinName csn,
+                     PinName ce,
+                     PinName irq) : spi_(mosi, miso, sck), nCS_(csn), ce_(ce), nIRQ_(irq) {
+
+    mode = _NRF24L01P_MODE_UNKNOWN;
+
+    disable();
+
+    nCS_ = 1;
+
+    spi_.frequency(_NRF24L01P_SPI_MAX_DATA_RATE/5);     // 2Mbit, 1/5th the maximum transfer rate for the SPI bus
+    spi_.format(8,0);                                   // 8-bit, ClockPhase = 0, ClockPolarity = 0
+
+    wait_us(_NRF24L01P_TIMING_Tundef2pd_us);    // Wait for Power-on reset
+
+    setRegister(_NRF24L01P_REG_CONFIG, 0); // Power Down
+
+    setRegister(_NRF24L01P_REG_STATUS, _NRF24L01P_STATUS_MAX_RT|_NRF24L01P_STATUS_TX_DS|_NRF24L01P_STATUS_RX_DR);   // Clear any pending interrupts
+
+    //
+    // Setup default configuration
+    //
+    disableAllRxPipes();
+    setRfFrequency();
+    setRfOutputPower();
+    setAirDataRate();
+    setCrcWidth();
+    setTxAddress();
+    setRxAddress();
+    disableAutoAcknowledge();
+    disableAutoRetransmit();
+    setTransferSize();
+
+    mode = _NRF24L01P_MODE_POWER_DOWN;
+
+}
+
+
+void nRF24L01P::powerUp(void) {
+
+    int config = getRegister(_NRF24L01P_REG_CONFIG);
+
+    config |= _NRF24L01P_CONFIG_PWR_UP;
+
+    setRegister(_NRF24L01P_REG_CONFIG, config);
+
+    // Wait until the nRF24L01+ powers up
+    wait_us( _NRF24L01P_TIMING_Tpd2stby_us );
+
+    mode = _NRF24L01P_MODE_STANDBY;
+
+}
+
+
+void nRF24L01P::powerDown(void) {
+
+    int config = getRegister(_NRF24L01P_REG_CONFIG);
+
+    config &= ~_NRF24L01P_CONFIG_PWR_UP;
+
+    setRegister(_NRF24L01P_REG_CONFIG, config);
+
+    // Wait until the nRF24L01+ powers down
+    wait_us( _NRF24L01P_TIMING_Tpd2stby_us );    // This *may* not be necessary (no timing is shown in the Datasheet), but just to be safe
+
+    mode = _NRF24L01P_MODE_POWER_DOWN;
+
+}
+
+
+void nRF24L01P::setReceiveMode(void) {
+
+    if ( _NRF24L01P_MODE_POWER_DOWN == mode ) powerUp();
+
+    int config = getRegister(_NRF24L01P_REG_CONFIG);
+
+    config |= _NRF24L01P_CONFIG_PRIM_RX;
+
+    setRegister(_NRF24L01P_REG_CONFIG, config);
+
+    mode = _NRF24L01P_MODE_RX;
+
+}
+
+
+void nRF24L01P::setTransmitMode(void) {
+
+    if ( _NRF24L01P_MODE_POWER_DOWN == mode ) powerUp();
+
+    int config = getRegister(_NRF24L01P_REG_CONFIG);
+
+    config &= ~_NRF24L01P_CONFIG_PRIM_RX;
+
+    setRegister(_NRF24L01P_REG_CONFIG, config);
+
+    mode = _NRF24L01P_MODE_TX;
+
+}
+
+
+void nRF24L01P::enable(void) {
+
+    ce_ = 1;
+    wait_us( _NRF24L01P_TIMING_Tpece2csn_us );
+
+}
+
+
+void nRF24L01P::disable(void) {
+
+    ce_ = 0;
+
+}
+
+void nRF24L01P::setRfFrequency(int frequency) {
+
+    if ( ( frequency < NRF24L01P_MIN_RF_FREQUENCY ) || ( frequency > NRF24L01P_MAX_RF_FREQUENCY ) ) {
+
+        error( "nRF24L01P: Invalid RF Frequency setting %d\r\n", frequency );
+        return;
+
+    }
+
+    int channel = ( frequency - NRF24L01P_MIN_RF_FREQUENCY ) & 0x7F;
+
+    setRegister(_NRF24L01P_REG_RF_CH, channel);
+
+}
+
+
+int nRF24L01P::getRfFrequency(void) {
+
+    int channel = getRegister(_NRF24L01P_REG_RF_CH) & 0x7F;
+
+    return ( channel + NRF24L01P_MIN_RF_FREQUENCY );
+
+}
+
+
+void nRF24L01P::setRfOutputPower(int power) {
+
+    int rfSetup = getRegister(_NRF24L01P_REG_RF_SETUP) & ~_NRF24L01P_RF_SETUP_RF_PWR_MASK;
+
+    switch ( power ) {
+
+        case NRF24L01P_TX_PWR_ZERO_DB:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_PWR_0DBM;
+            break;
+
+        case NRF24L01P_TX_PWR_MINUS_6_DB:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_PWR_MINUS_6DBM;
+            break;
+
+        case NRF24L01P_TX_PWR_MINUS_12_DB:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_PWR_MINUS_12DBM;
+            break;
+
+        case NRF24L01P_TX_PWR_MINUS_18_DB:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_PWR_MINUS_18DBM;
+            break;
+
+        default:
+            error( "nRF24L01P: Invalid RF Output Power setting %d\r\n", power );
+            return;
+
+    }
+
+    setRegister(_NRF24L01P_REG_RF_SETUP, rfSetup);
+
+}
+
+
+int nRF24L01P::getRfOutputPower(void) {
+
+    int rfPwr = getRegister(_NRF24L01P_REG_RF_SETUP) & _NRF24L01P_RF_SETUP_RF_PWR_MASK;
+
+    switch ( rfPwr ) {
+
+        case _NRF24L01P_RF_SETUP_RF_PWR_0DBM:
+            return NRF24L01P_TX_PWR_ZERO_DB;
+
+        case _NRF24L01P_RF_SETUP_RF_PWR_MINUS_6DBM:
+            return NRF24L01P_TX_PWR_MINUS_6_DB;
+
+        case _NRF24L01P_RF_SETUP_RF_PWR_MINUS_12DBM:
+            return NRF24L01P_TX_PWR_MINUS_12_DB;
+
+        case _NRF24L01P_RF_SETUP_RF_PWR_MINUS_18DBM:
+            return NRF24L01P_TX_PWR_MINUS_18_DB;
+
+        default:
+            error( "nRF24L01P: Unknown RF Output Power value %d\r\n", rfPwr );
+            return 0;
+
+    }
+}
+
+
+void nRF24L01P::setAirDataRate(int rate) {
+
+    int rfSetup = getRegister(_NRF24L01P_REG_RF_SETUP) & ~_NRF24L01P_RF_SETUP_RF_DR_MASK;
+
+    switch ( rate ) {
+
+        case NRF24L01P_DATARATE_250_KBPS:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_DR_250KBPS;
+            break;
+
+        case NRF24L01P_DATARATE_1_MBPS:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_DR_1MBPS;
+            break;
+
+        case NRF24L01P_DATARATE_2_MBPS:
+            rfSetup |= _NRF24L01P_RF_SETUP_RF_DR_2MBPS;
+            break;
+
+        default:
+            error( "nRF24L01P: Invalid Air Data Rate setting %d\r\n", rate );
+            return;
+
+    }
+
+    setRegister(_NRF24L01P_REG_RF_SETUP, rfSetup);
+
+}
+
+
+int nRF24L01P::getAirDataRate(void) {
+
+    int rfDataRate = getRegister(_NRF24L01P_REG_RF_SETUP) & _NRF24L01P_RF_SETUP_RF_DR_MASK;
+
+    switch ( rfDataRate ) {
+
+        case _NRF24L01P_RF_SETUP_RF_DR_250KBPS:
+            return NRF24L01P_DATARATE_250_KBPS;
+
+        case _NRF24L01P_RF_SETUP_RF_DR_1MBPS:
+            return NRF24L01P_DATARATE_1_MBPS;
+
+        case _NRF24L01P_RF_SETUP_RF_DR_2MBPS:
+            return NRF24L01P_DATARATE_2_MBPS;
+
+        default:
+            error( "nRF24L01P: Unknown Air Data Rate value %d\r\n", rfDataRate );
+            return 0;
+
+    }
+}
+
+
+void nRF24L01P::setCrcWidth(int width) {
+
+    int config = getRegister(_NRF24L01P_REG_CONFIG) & ~_NRF24L01P_CONFIG_CRC_MASK;
+
+    switch ( width ) {
+
+        case NRF24L01P_CRC_NONE:
+            config |= _NRF24L01P_CONFIG_CRC_NONE;
+            break;
+
+        case NRF24L01P_CRC_8_BIT:
+            config |= _NRF24L01P_CONFIG_CRC_8BIT;
+            break;
+
+        case NRF24L01P_CRC_16_BIT:
+            config |= _NRF24L01P_CONFIG_CRC_16BIT;
+            break;
+
+        default:
+            error( "nRF24L01P: Invalid CRC Width setting %d\r\n", width );
+            return;
+
+    }
+
+    setRegister(_NRF24L01P_REG_CONFIG, config);
+
+}
+
+
+int nRF24L01P::getCrcWidth(void) {
+
+    int crcWidth = getRegister(_NRF24L01P_REG_CONFIG) & _NRF24L01P_CONFIG_CRC_MASK;
+
+    switch ( crcWidth ) {
+
+        case _NRF24L01P_CONFIG_CRC_NONE:
+            return NRF24L01P_CRC_NONE;
+
+        case _NRF24L01P_CONFIG_CRC_8BIT:
+            return NRF24L01P_CRC_8_BIT;
+
+        case _NRF24L01P_CONFIG_CRC_16BIT:
+            return NRF24L01P_CRC_16_BIT;
+
+        default:
+            error( "nRF24L01P: Unknown CRC Width value %d\r\n", crcWidth );
+            return 0;
+
+    }
+}
+
+
+void nRF24L01P::setTransferSize(int size, int pipe) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid Transfer Size pipe number %d\r\n", pipe );
+        return;
+
+    }
+
+    if ( ( size < 0 ) || ( size > _NRF24L01P_RX_FIFO_SIZE ) ) {
+
+        error( "nRF24L01P: Invalid Transfer Size setting %d\r\n", size );
+        return;
+
+    }
+
+    int rxPwPxRegister = _NRF24L01P_REG_RX_PW_P0 + ( pipe - NRF24L01P_PIPE_P0 );
+
+    setRegister(rxPwPxRegister, ( size & _NRF24L01P_RX_PW_Px_MASK ) );
+
+}
+
+
+int nRF24L01P::getTransferSize(int pipe) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid Transfer Size pipe number %d\r\n", pipe );
+        return 0;
+
+    }
+
+    int rxPwPxRegister = _NRF24L01P_REG_RX_PW_P0 + ( pipe - NRF24L01P_PIPE_P0 );
+
+    int size = getRegister(rxPwPxRegister);
+    
+    return ( size & _NRF24L01P_RX_PW_Px_MASK );
+
+}
+
+
+void nRF24L01P::disableAllRxPipes(void) {
+
+    setRegister(_NRF24L01P_REG_EN_RXADDR, _NRF24L01P_EN_RXADDR_NONE);
+
+}
+
+
+void nRF24L01P::disableAutoAcknowledge(void) {
+
+    setRegister(_NRF24L01P_REG_EN_AA, _NRF24L01P_EN_AA_NONE);
+
+}
+
+
+void nRF24L01P::enableAutoAcknowledge(int pipe) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid Enable AutoAcknowledge pipe number %d\r\n", pipe );
+        return;
+
+    }
+
+    int enAA = getRegister(_NRF24L01P_REG_EN_AA);
+
+    enAA |= ( 1 << (pipe - NRF24L01P_PIPE_P0) );
+
+    setRegister(_NRF24L01P_REG_EN_AA, enAA);
+
+}
+
+
+void nRF24L01P::disableAutoRetransmit(void) {
+
+    setRegister(_NRF24L01P_REG_SETUP_RETR, _NRF24L01P_SETUP_RETR_NONE);
+
+}
+
+void nRF24L01P::setRxAddress(unsigned long long address, int width, int pipe) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid setRxAddress pipe number %d\r\n", pipe );
+        return;
+
+    }
+
+    if ( ( pipe == NRF24L01P_PIPE_P0 ) || ( pipe == NRF24L01P_PIPE_P1 ) ) {
+
+        int setupAw = getRegister(_NRF24L01P_REG_SETUP_AW) & ~_NRF24L01P_SETUP_AW_AW_MASK;
+    
+        switch ( width ) {
+    
+            case 3:
+                setupAw |= _NRF24L01P_SETUP_AW_AW_3BYTE;
+                break;
+    
+            case 4:
+                setupAw |= _NRF24L01P_SETUP_AW_AW_4BYTE;
+                break;
+    
+            case 5:
+                setupAw |= _NRF24L01P_SETUP_AW_AW_5BYTE;
+                break;
+    
+            default:
+                error( "nRF24L01P: Invalid setRxAddress width setting %d\r\n", width );
+                return;
+    
+        }
+    
+        setRegister(_NRF24L01P_REG_SETUP_AW, setupAw);
+
+    } else {
+    
+        width = 1;
+    
+    }
+
+    int rxAddrPxRegister = _NRF24L01P_REG_RX_ADDR_P0 + ( pipe - NRF24L01P_PIPE_P0 );
+
+    int cn = (_NRF24L01P_SPI_CMD_WR_REG | (rxAddrPxRegister & _NRF24L01P_REG_ADDRESS_MASK));
+
+    nCS_ = 0;
+
+    int status = spi_.write(cn);
+
+    while ( width-- > 0 ) {
+
+        //
+        // LSByte first
+        //
+        spi_.write((int) (address & 0xFF));
+        address >>= 8;
+
+    }
+
+    nCS_ = 1;
+
+    int enRxAddr = getRegister(_NRF24L01P_REG_EN_RXADDR);
+
+    enRxAddr |= (1 << ( pipe - NRF24L01P_PIPE_P0 ) );
+
+    setRegister(_NRF24L01P_REG_EN_RXADDR, enRxAddr);
+}
+
+/*
+ * This version of setRxAddress is just a wrapper for the version that takes 'long long's,
+ *  in case the main code doesn't want to deal with long long's.
+ */
+void nRF24L01P::setRxAddress(unsigned long msb_address, unsigned long lsb_address, int width, int pipe) {
+
+    unsigned long long address = ( ( (unsigned long long) msb_address ) << 32 ) | ( ( (unsigned long long) lsb_address ) << 0 );
+
+    setRxAddress(address, width, pipe);
+
+}
+
+
+/*
+ * This version of setTxAddress is just a wrapper for the version that takes 'long long's,
+ *  in case the main code doesn't want to deal with long long's.
+ */
+void nRF24L01P::setTxAddress(unsigned long msb_address, unsigned long lsb_address, int width) {
+
+    unsigned long long address = ( ( (unsigned long long) msb_address ) << 32 ) | ( ( (unsigned long long) lsb_address ) << 0 );
+
+    setTxAddress(address, width);
+
+}
+
+
+void nRF24L01P::setTxAddress(unsigned long long address, int width) {
+
+    int setupAw = getRegister(_NRF24L01P_REG_SETUP_AW) & ~_NRF24L01P_SETUP_AW_AW_MASK;
+
+    switch ( width ) {
+
+        case 3:
+            setupAw |= _NRF24L01P_SETUP_AW_AW_3BYTE;
+            break;
+
+        case 4:
+            setupAw |= _NRF24L01P_SETUP_AW_AW_4BYTE;
+            break;
+
+        case 5:
+            setupAw |= _NRF24L01P_SETUP_AW_AW_5BYTE;
+            break;
+
+        default:
+            error( "nRF24L01P: Invalid setTxAddress width setting %d\r\n", width );
+            return;
+
+    }
+
+    setRegister(_NRF24L01P_REG_SETUP_AW, setupAw);
+
+    int cn = (_NRF24L01P_SPI_CMD_WR_REG | (_NRF24L01P_REG_TX_ADDR & _NRF24L01P_REG_ADDRESS_MASK));
+
+    nCS_ = 0;
+
+    int status = spi_.write(cn);
+
+    while ( width-- > 0 ) {
+
+        //
+        // LSByte first
+        //
+        spi_.write((int) (address & 0xFF));
+        address >>= 8;
+
+    }
+
+    nCS_ = 1;
+
+}
+
+
+unsigned long long nRF24L01P::getRxAddress(int pipe) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid setRxAddress pipe number %d\r\n", pipe );
+        return 0;
+
+    }
+
+    int width;
+
+    if ( ( pipe == NRF24L01P_PIPE_P0 ) || ( pipe == NRF24L01P_PIPE_P1 ) ) {
+
+        int setupAw = getRegister(_NRF24L01P_REG_SETUP_AW) & _NRF24L01P_SETUP_AW_AW_MASK;
+
+        switch ( setupAw ) {
+
+            case _NRF24L01P_SETUP_AW_AW_3BYTE:
+                width = 3;
+                break;
+
+            case _NRF24L01P_SETUP_AW_AW_4BYTE:
+                width = 4;
+                break;
+
+            case _NRF24L01P_SETUP_AW_AW_5BYTE:
+                width = 5;
+                break;
+
+            default:
+                error( "nRF24L01P: Unknown getRxAddress width value %d\r\n", setupAw );
+                return 0;
+
+        }
+
+    } else {
+
+        width = 1;
+
+    }
+
+    int rxAddrPxRegister = _NRF24L01P_REG_RX_ADDR_P0 + ( pipe - NRF24L01P_PIPE_P0 );
+
+    int cn = (_NRF24L01P_SPI_CMD_RD_REG | (rxAddrPxRegister & _NRF24L01P_REG_ADDRESS_MASK));
+
+    unsigned long long address = 0;
+
+    nCS_ = 0;
+
+    int status = spi_.write(cn);
+
+    for ( int i=0; i<width; i++ ) {
+
+        //
+        // LSByte first
+        //
+        address |= ( ( (unsigned long long)( spi_.write(_NRF24L01P_SPI_CMD_NOP) & 0xFF ) ) << (i*8) );
+
+    }
+
+    nCS_ = 1;
+
+    if ( !( ( pipe == NRF24L01P_PIPE_P0 ) || ( pipe == NRF24L01P_PIPE_P1 ) ) ) {
+
+        address |= ( getRxAddress(NRF24L01P_PIPE_P1) & ~((unsigned long long) 0xFF) );
+
+    }
+
+    return address;
+
+}
+
+    
+unsigned long long nRF24L01P::getTxAddress(void) {
+
+    int setupAw = getRegister(_NRF24L01P_REG_SETUP_AW) & _NRF24L01P_SETUP_AW_AW_MASK;
+
+    int width;
+
+    switch ( setupAw ) {
+
+        case _NRF24L01P_SETUP_AW_AW_3BYTE:
+            width = 3;
+            break;
+
+        case _NRF24L01P_SETUP_AW_AW_4BYTE:
+            width = 4;
+            break;
+
+        case _NRF24L01P_SETUP_AW_AW_5BYTE:
+            width = 5;
+            break;
+
+        default:
+            error( "nRF24L01P: Unknown getTxAddress width value %d\r\n", setupAw );
+            return 0;
+
+    }
+
+    int cn = (_NRF24L01P_SPI_CMD_RD_REG | (_NRF24L01P_REG_TX_ADDR & _NRF24L01P_REG_ADDRESS_MASK));
+
+    unsigned long long address = 0;
+
+    nCS_ = 0;
+
+    int status = spi_.write(cn);
+
+    for ( int i=0; i<width; i++ ) {
+
+        //
+        // LSByte first
+        //
+        address |= ( ( (unsigned long long)( spi_.write(_NRF24L01P_SPI_CMD_NOP) & 0xFF ) ) << (i*8) );
+
+    }
+
+    nCS_ = 1;
+
+    return address;
+}
+
+
+bool nRF24L01P::readable(int pipe) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid readable pipe number %d\r\n", pipe );
+        return false;
+
+    }
+
+    int status = getStatusRegister();
+
+    return ( ( status & _NRF24L01P_STATUS_RX_DR ) && ( ( ( status & _NRF24L01P_STATUS_RX_P_NO ) >> 1 ) == ( pipe & 0x7 ) ) );
+
+}
+
+
+int nRF24L01P::write(int pipe, char *data, int count) {
+
+    // Note: the pipe number is ignored in a Transmit / write
+
+    //
+    // Save the CE state
+    //
+    int originalCe = ce_;
+    disable();
+
+    if ( count <= 0 ) return 0;
+
+    if ( count > _NRF24L01P_TX_FIFO_SIZE ) count = _NRF24L01P_TX_FIFO_SIZE;
+
+    // Clear the Status bit
+    setRegister(_NRF24L01P_REG_STATUS, _NRF24L01P_STATUS_TX_DS);
+	
+    nCS_ = 0;
+
+    int status = spi_.write(_NRF24L01P_SPI_CMD_WR_TX_PAYLOAD);
+
+    for ( int i = 0; i < count; i++ ) {
+
+        spi_.write(*data++);
+
+    }
+
+    nCS_ = 1;
+
+    int originalMode = mode;
+    setTransmitMode();
+
+    enable();
+    wait_us(_NRF24L01P_TIMING_Thce_us);
+    disable();
+
+    while ( !( getStatusRegister() & _NRF24L01P_STATUS_TX_DS ) ) {
+
+        // Wait for the transfer to complete
+
+    }
+
+    // Clear the Status bit
+    setRegister(_NRF24L01P_REG_STATUS, _NRF24L01P_STATUS_TX_DS);
+
+    if ( originalMode == _NRF24L01P_MODE_RX ) {
+
+        setReceiveMode();
+
+    }
+
+    ce_ = originalCe;
+    wait_us( _NRF24L01P_TIMING_Tpece2csn_us );
+
+    return count;
+
+}
+
+
+int nRF24L01P::read(int pipe, char *data, int count) {
+
+    if ( ( pipe < NRF24L01P_PIPE_P0 ) || ( pipe > NRF24L01P_PIPE_P5 ) ) {
+
+        error( "nRF24L01P: Invalid read pipe number %d\r\n", pipe );
+        return -1;
+
+    }
+
+    if ( count <= 0 ) return 0;
+
+    if ( count > _NRF24L01P_RX_FIFO_SIZE ) count = _NRF24L01P_RX_FIFO_SIZE;
+
+    if ( readable(pipe) ) {
+
+        nCS_ = 0;
+
+        int status = spi_.write(_NRF24L01P_SPI_CMD_R_RX_PL_WID);
+
+        int rxPayloadWidth = spi_.write(_NRF24L01P_SPI_CMD_NOP);
+        
+        nCS_ = 1;
+
+        if ( ( rxPayloadWidth < 0 ) || ( rxPayloadWidth > _NRF24L01P_RX_FIFO_SIZE ) ) {
+    
+            // Received payload error: need to flush the FIFO
+
+            nCS_ = 0;
+    
+            int status = spi_.write(_NRF24L01P_SPI_CMD_FLUSH_RX);
+    
+            int rxPayloadWidth = spi_.write(_NRF24L01P_SPI_CMD_NOP);
+            
+            nCS_ = 1;
+            
+            //
+            // At this point, we should retry the reception,
+            //  but for now we'll just fall through...
+            //
+
+        } else {
+
+            if ( rxPayloadWidth < count ) count = rxPayloadWidth;
+
+            nCS_ = 0;
+        
+            int status = spi_.write(_NRF24L01P_SPI_CMD_RD_RX_PAYLOAD);
+        
+            for ( int i = 0; i < count; i++ ) {
+        
+                *data++ = spi_.write(_NRF24L01P_SPI_CMD_NOP);
+        
+            }
+
+            nCS_ = 1;
+
+            // Clear the Status bit
+            setRegister(_NRF24L01P_REG_STATUS, _NRF24L01P_STATUS_RX_DR);
+
+            return count;
+
+        }
+
+    } else {
+
+        //
+        // What should we do if there is no 'readable' data?
+        //  We could wait for data to arrive, but for now, we'll
+        //  just return with no data.
+        //
+        return 0;
+
+    }
+
+    //
+    // We get here because an error condition occured;
+    //  We could wait for data to arrive, but for now, we'll
+    //  just return with no data.
+    //
+    return -1;
+
+}
+
+void nRF24L01P::setRegister(int regAddress, int regData) {
+
+    //
+    // Save the CE state
+    //
+    int originalCe = ce_;
+    disable();
+
+    int cn = (_NRF24L01P_SPI_CMD_WR_REG | (regAddress & _NRF24L01P_REG_ADDRESS_MASK));
+
+    nCS_ = 0;
+
+    int status = spi_.write(cn);
+
+    spi_.write(regData & 0xFF);
+
+    nCS_ = 1;
+
+    ce_ = originalCe;
+    wait_us( _NRF24L01P_TIMING_Tpece2csn_us );
+
+}
+
+
+int nRF24L01P::getRegister(int regAddress) {
+
+    int cn = (_NRF24L01P_SPI_CMD_RD_REG | (regAddress & _NRF24L01P_REG_ADDRESS_MASK));
+
+    nCS_ = 0;
+
+    int status = spi_.write(cn);
+
+    int dn = spi_.write(_NRF24L01P_SPI_CMD_NOP);
+
+    nCS_ = 1;
+
+    return dn;
+
+}
+
+int nRF24L01P::getStatusRegister(void) {
+
+    nCS_ = 0;
+
+    int status = spi_.write(_NRF24L01P_SPI_CMD_NOP);
+
+    nCS_ = 1;
+
+    return status;
+
+}

diff -r 000000000000 -r 8ae48233b4e4 nRF24L01P.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nRF24L01P.h	Wed Jan 19 22:59:48 2011 +0000
@@ -0,0 +1,347 @@
+/**
+ * @file nRF24L01P.h
+ *
+ * @author Owen Edwards
+ * 
+ * @section LICENSE
+ *
+ * Copyright (c) 2010 Owen Edwards
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * @section DESCRIPTION
+ *
+ * nRF24L01+ Single Chip 2.4GHz Transceiver from Nordic Semiconductor.
+ *
+ * Datasheet:
+ *
+ * http://www.nordicsemi.no/files/Product/data_sheet/nRF24L01P_Product_Specification_1_0.pdf
+ */
+
+#ifndef __NRF24L01P_H__
+#define __NRF24L01P_H__
+
+/**
+ * Includes
+ */
+#include "mbed.h"
+
+/**
+ * Defines
+ */
+#define NRF24L01P_TX_PWR_ZERO_DB         0
+#define NRF24L01P_TX_PWR_MINUS_6_DB     -6
+#define NRF24L01P_TX_PWR_MINUS_12_DB   -12
+#define NRF24L01P_TX_PWR_MINUS_18_DB   -18
+
+#define NRF24L01P_DATARATE_250_KBPS    250
+#define NRF24L01P_DATARATE_1_MBPS     1000
+#define NRF24L01P_DATARATE_2_MBPS     2000
+
+#define NRF24L01P_CRC_NONE               0
+#define NRF24L01P_CRC_8_BIT              8
+#define NRF24L01P_CRC_16_BIT            16
+
+#define NRF24L01P_MIN_RF_FREQUENCY    2400
+#define NRF24L01P_MAX_RF_FREQUENCY    2525
+
+#define NRF24L01P_PIPE_P0                0
+#define NRF24L01P_PIPE_P1                1
+#define NRF24L01P_PIPE_P2                2
+#define NRF24L01P_PIPE_P3                3
+#define NRF24L01P_PIPE_P4                4
+#define NRF24L01P_PIPE_P5                5
+
+/**
+* Default setup for the nRF24L01+, based on the Sparkfun "Nordic Serial Interface Board"
+*  for evaluation (http://www.sparkfun.com/products/9019)
+*/
+#define DEFAULT_NRF24L01P_ADDRESS       ((unsigned long long) 0xE7E7E7E7E7 )
+#define DEFAULT_NRF24L01P_ADDRESS_WIDTH  5
+#define DEFAULT_NRF24L01P_CRC            NRF24L01P_CRC_8_BIT
+#define DEFAULT_NRF24L01P_RF_FREQUENCY  (NRF24L01P_MIN_RF_FREQUENCY + 2)
+#define DEFAULT_NRF24L01P_DATARATE       NRF24L01P_DATARATE_1_MBPS
+#define DEFAULT_NRF24L01P_TX_PWR         NRF24L01P_TX_PWR_ZERO_DB
+#define DEFAULT_NRF24L01P_TRANSFER_SIZE  4
+
+/**
+ * nRF24L01+ Single Chip 2.4GHz Transceiver from Nordic Semiconductor.
+ */
+class nRF24L01P {
+
+public:
+
+    /**
+     * Constructor.
+     *
+     * @param mosi mbed pin to use for MOSI line of SPI interface.
+     * @param miso mbed pin to use for MISO line of SPI interface.
+     * @param sck mbed pin to use for SCK line of SPI interface.
+     * @param csn mbed pin to use for not chip select line of SPI interface.
+     * @param ce mbed pin to use for the chip enable line.
+     * @param irq mbed pin to use for the interrupt request line.
+     */
+    nRF24L01P(PinName mosi, PinName miso, PinName sck, PinName csn, PinName ce, PinName irq = NC);
+
+    /**
+     * Set the RF frequency.
+     *
+     * @param frequency the frequency of RF transmission in MHz (2400..2525).
+     */
+    void setRfFrequency(int frequency = DEFAULT_NRF24L01P_RF_FREQUENCY);
+
+    /**
+     * Get the RF frequency.
+     *
+     * @return the frequency of RF transmission in MHz (2400..2525).
+     */
+    int getRfFrequency(void);
+
+    /**
+     * Set the RF output power.
+     *
+     * @param power the RF output power in dBm (0, -6, -12 or -18).
+     */
+    void setRfOutputPower(int power = DEFAULT_NRF24L01P_TX_PWR);
+
+    /**
+     * Get the RF output power.
+     *
+     * @return the RF output power in dBm (0, -6, -12 or -18).
+     */
+    int getRfOutputPower(void);
+
+    /**
+     * Set the Air data rate.
+     *
+     * @param rate the air data rate in kbps (250, 1M or 2M).
+     */
+    void setAirDataRate(int rate = DEFAULT_NRF24L01P_DATARATE);
+
+    /**
+     * Get the Air data rate.
+     *
+     * @return the air data rate in kbps (250, 1M or 2M).
+     */
+    int getAirDataRate(void);
+
+    /**
+     * Set the CRC width.
+     *
+     * @param width the number of bits for the CRC (0, 8 or 16).
+     */
+    void setCrcWidth(int width = DEFAULT_NRF24L01P_CRC);
+
+    /**
+     * Get the CRC width.
+     *
+     * @return the number of bits for the CRC (0, 8 or 16).
+     */
+    int getCrcWidth(void);
+
+    /**
+     * Set the Receive address.
+     *
+     * @param address address associated with the particular pipe
+     * @param width width of the address in bytes (3..5)
+     * @param pipe pipe to associate the address with (0..5, default 0)
+     *
+     * Note that Pipes 0 & 1 have 3, 4 or 5 byte addresses,
+     *  while Pipes 2..5 only use the lowest byte (bits 7..0) of the
+     *  address provided here, and use 2, 3 or 4 bytes from Pipe 1's address.
+     *  The width parameter is ignored for Pipes 2..5.
+     */
+    void setRxAddress(unsigned long long address = DEFAULT_NRF24L01P_ADDRESS, int width = DEFAULT_NRF24L01P_ADDRESS_WIDTH, int pipe = NRF24L01P_PIPE_P0);
+
+    void setRxAddress(unsigned long msb_address, unsigned long lsb_address, int width, int pipe = NRF24L01P_PIPE_P0);
+
+    /**
+     * Set the Transmit address.
+     *
+     * @param address address for transmission
+     * @param width width of the address in bytes (3..5)
+     *
+     * Note that the address width is shared with the Receive pipes,
+     *  so a change to that address width affect transmissions.
+     */
+    void setTxAddress(unsigned long long address = DEFAULT_NRF24L01P_ADDRESS, int width = DEFAULT_NRF24L01P_ADDRESS_WIDTH);
+
+    void setTxAddress(unsigned long msb_address, unsigned long lsb_address, int width);
+
+    /**
+     * Get the Receive address.
+     *
+     * @param pipe pipe to get the address from (0..5, default 0)
+     * @return the address associated with the particular pipe
+     */
+    unsigned long long getRxAddress(int pipe = NRF24L01P_PIPE_P0);
+
+    /**
+     * Get the Transmit address.
+     *
+     * @return address address for transmission
+     */
+    unsigned long long getTxAddress(void);
+
+    /**
+     * Set the transfer size.
+     *
+     * @param size the size of the transfer, in bytes (1..32)
+     * @param pipe pipe for the transfer (0..5, default 0)
+     */
+    void setTransferSize(int size = DEFAULT_NRF24L01P_TRANSFER_SIZE, int pipe = NRF24L01P_PIPE_P0);
+
+    /**
+     * Get the transfer size.
+     *
+     * @return the size of the transfer, in bytes (1..32).
+     */
+    int getTransferSize(int pipe = NRF24L01P_PIPE_P0);
+
+
+    /**
+     * Get the RPD (Received Power Detector) state.
+     *
+     * @return true if the received power exceeded -64dBm
+     */
+    bool getRPD(void);
+
+    /**
+     * Put the nRF24L01+ into Receive mode
+     */
+    void setReceiveMode(void);
+
+    /**
+     * Put the nRF24L01+ into Transmit mode
+     */
+    void setTransmitMode(void);
+
+    /**
+     * Power up the nRF24L01+ into Standby mode
+     */
+    void powerUp(void);
+
+    /**
+     * Power down the nRF24L01+ into Power Down mode
+     */
+    void powerDown(void);
+
+    /**
+     * Enable the nRF24L01+ to Receive or Transmit (using the CE pin)
+     */
+    void enable(void);
+
+    /**
+     * Disable the nRF24L01+ to Receive or Transmit (using the CE pin)
+     */
+    void disable(void);
+
+    /**
+     * Transmit data
+     *
+     * @param pipe is ignored (included for consistency with file write routine)
+     * @param data pointer to an array of bytes to write
+     * @param count the number of bytes to send (1..32)
+     * @return the number of bytes actually written, or -1 for an error
+     */
+    int write(int pipe, char *data, int count);
+    
+    /**
+     * Receive data
+     *
+     * @param pipe the receive pipe to get data from
+     * @param data pointer to an array of bytes to store the received data
+     * @param count the number of bytes to receive (1..32)
+     * @return the number of bytes actually received, 0 if none are received, or -1 for an error
+     */
+    int read(int pipe, char *data, int count);
+
+    /**
+     * Determine if there is data available to read
+     *
+     * @param pipe the receive pipe to check for data
+     * @return true if the is data waiting in the given pipe
+     */
+    bool readable(int pipe = NRF24L01P_PIPE_P0);
+
+    /**
+     * Disable all receive pipes
+     *
+     * Note: receive pipes are enabled when their address is set.
+     */
+    void disableAllRxPipes(void);
+    
+    /**
+     * Disable AutoAcknowledge function
+     */
+    void disableAutoAcknowledge(void);
+    
+    /**
+     * Enable AutoAcknowledge function
+     *
+     * @param pipe the receive pipe
+     */
+    void enableAutoAcknowledge(int pipe = NRF24L01P_PIPE_P0);
+    
+    /**
+     * Disable AutoRetransmit function
+     */
+    void disableAutoRetransmit(void);
+    
+    /**
+     * Enable AutoRetransmit function
+     *
+     * @param delay the delay between restransmits, in uS (250uS..4000uS)
+     * @param count number of retransmits before generating an error (1..15)
+     */
+    void enableAutoRetransmit(int delay, int count);
+
+private:
+
+    /**
+     * Get the contents of an addressable register.
+     *
+     * @param regAddress address of the register
+     * @return the contents of the register
+     */
+    int getRegister(int regAddress);
+
+    /**
+     * Set the contents of an addressable register.
+     *
+     * @param regAddress address of the register
+     * @param regData data to write to the register
+     */
+    void setRegister(int regAddress, int regData);
+
+    /**
+     * Get the contents of the status register.
+     *
+     * @return the contents of the status register
+     */
+    int getStatusRegister(void);
+
+    SPI         spi_;
+    DigitalOut  nCS_;
+    DigitalOut  ce_;
+    InterruptIn nIRQ_;
+
+    int mode;
+
+};
+
+#endif /* __NRF24L01P_H__ */