Diff: XBee/XBee.cpp

Revision:

0:fcaad0dfa051

Child:

1:794d1d3e4a08

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/XBee/XBee.cpp	Fri May 08 11:50:56 2015 +0200
@@ -0,0 +1,732 @@
+/**
+ * Copyright (c) 2015 Digi International Inc.,
+ * All rights not expressly granted are reserved.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Digi International Inc. 11001 Bren Road East, Minnetonka, MN 55343
+ * =======================================================================
+ */
+
+#include "XBeeLib.h"
+#include "FrameHandlers/FH_ModemStatus.h"
+
+/* States for the state machine that processes incoming data on the serial port */
+#define WAITING_FOR_START_FRAME (0)
+#define WAITING_FOR_LENGTH_MSB  (1)
+#define WAITING_FOR_LENGTH_LSB  (2)
+#define WAITING_FOR_PAYLOAD     (3)
+#define WAITING_FOR_CHECKSUM    (4)
+
+#define IS_API2()               (_mode == ModeAPI2)
+#define IS_API_MODE()           (_mode == ModeAPI1 || _mode == ModeAPI2)
+
+using namespace XBeeLib;
+
+Timer XBee::_timer;
+FrameBuffer XBee::_framebuf;
+
+/* Class constructor */
+XBee::XBee(PinName tx, PinName rx, PinName reset, PinName rts, PinName cts, int baud) :
+    _mode(ModeUnknown), _type(Unknown), _hw_version(0), _fw_version(0), _timeout_ms(SYNC_OPS_TIMEOUT_MS), _dev_addr64(ADDR64_UNASSIGNED), _dev_addr16(ADDR16_UNKNOWN),
+    _reset(NULL), _tx_options(0), _bc_radius(0), _hw_reset_cnt(0), _wd_reset_cnt(0), _reset_timeout(0), _modem_status_handler(NULL), _modem_status(AtCmdFrame::HwReset), _initializing(true), _pm_mode(SleepDisabled)
+{
+
+    if (reset != NC) {
+        _reset = new DigitalOut(reset);
+    }
+#if defined(ENABLE_PM_SUPPORT)
+    _on_sleep = NULL;
+    _sleep_req = NULL;
+#endif /* defined(ENABLE_PM_SUPPORT) */
+
+    _uart = new RawSerial(tx, rx);
+    _uart->baud(baud);
+#if defined(DEVICE_SERIAL_FC)
+    if (rts != NC && cts != NC) {
+        _uart->set_flow_control(SerialBase::RTSCTS, rts, cts);
+    }
+#endif
+    /* Enable the reception of bytes on the serial interface by providing a cb */
+    _uart->attach(this, &XBee::uart_read_cb, Serial::RxIrq);
+
+    for (int i = 0; i < MAX_FRAME_HANDLERS; i++) {
+        _fhandlers[i] = NULL;
+    }
+}
+
+/* Class destructor */
+XBee::~XBee()
+{
+    unregister_modem_status_cb();
+
+    if (_uart != NULL) {
+        delete _uart;
+    }
+    if (_reset != NULL) {
+        delete _reset;
+    }
+}
+
+#include <inttypes.h>
+
+RadioStatus XBee::init(void)
+{
+    AtCmdFrame::AtCmdResp cmd_resp;
+    uint32_t var32;
+
+    /* Start the timer, used for the timeouts */
+    _timer.reset();
+    _timer.start();
+
+    _initializing = true;
+
+    device_reset();
+
+    /* Check if radio is in API1 or API2 _mode */
+    cmd_resp = get_param("AP", &var32);
+    if (cmd_resp != AtCmdFrame::AtCmdRespOk)
+        return Failure;
+
+    _mode = (RadioMode)var32;
+
+    /* Read the device unique 64b address */
+    uint32_t serialn_high, serialn_low;
+    cmd_resp = get_param("SH", &serialn_high);
+    if (cmd_resp != AtCmdFrame::AtCmdRespOk)
+        return Failure;
+    cmd_resp = get_param("SL", &serialn_low);
+    if (cmd_resp != AtCmdFrame::AtCmdRespOk)
+        return Failure;
+
+    _dev_addr64 = ((uint64_t)serialn_high << 32) | serialn_low;
+
+    /* Read some important parameters */
+    cmd_resp = get_param("HV", &var32);
+    if (cmd_resp != AtCmdFrame::AtCmdRespOk)
+        return Failure;
+    _hw_version = var32;
+
+    cmd_resp = get_param("VR", &var32);
+    if (cmd_resp != AtCmdFrame::AtCmdRespOk)
+        return Failure;
+    _fw_version = var32;
+
+    cmd_resp = get_param("MY", &var32);
+    if (cmd_resp != AtCmdFrame::AtCmdRespOk)
+        return Failure;
+    _dev_addr16 = var32;
+    _type = (RadioType)(_hw_version >> 8);
+
+    digi_log(LogLevelInfo, "mode:   %02x\r\n", (uint8_t)_mode);
+    digi_log(LogLevelInfo, "HV:     %04x\r\n", _hw_version);
+    digi_log(LogLevelInfo, "VR:     %04x\r\n", _fw_version);
+    digi_log(LogLevelInfo, "ADDR64: %08x:%08x\r\n", UINT64_HI32(_dev_addr64), UINT64_LO32(_dev_addr64));
+    digi_log(LogLevelInfo, "ADDR16: %04x\r\n", _dev_addr16);
+
+    _initializing = false;
+    if (_modem_status_handler != NULL) {
+        const ApiFrame frame = ApiFrame(ApiFrame::AtModemStatus, (uint8_t *)&_modem_status, sizeof(_modem_status));
+        _modem_status_handler->process_frame_data(&frame);
+    }   
+
+    return Success;
+}
+
+uint64_t XBee::get_addr64() const
+{
+    return _dev_addr64;
+}
+
+uint16_t XBee::get_addr16() const
+{
+    return _dev_addr16;
+}
+
+RadioStatus XBee::hardware_reset()
+{
+    if (_reset != NULL) {
+        volatile uint16_t * const rst_cnt_p = &_hw_reset_cnt;
+        const uint16_t init_rst_cnt = *rst_cnt_p;
+        *_reset = 0;
+        wait_ms(10);
+        *_reset = 1;
+        return wait_for_module_to_reset(rst_cnt_p, init_rst_cnt);
+    }
+
+    return Failure;
+}
+
+RadioStatus XBee::device_reset()
+{
+    if (hardware_reset() == Success)
+        return Success;
+
+    return software_reset();
+}
+
+RadioStatus XBee::wait_for_module_to_reset(volatile uint16_t *rst_cnt_p, uint16_t init_rst_cnt)
+{
+    const int rst_timeout = _timer.read_ms() + _reset_timeout;
+    while (*rst_cnt_p == init_rst_cnt && _timer.read_ms() < rst_timeout) {
+        wait_ms(100);
+    }
+
+    if (_reset_timeout && *rst_cnt_p == init_rst_cnt) {
+        digi_log(LogLevelWarning, "Reset Timeout\r\n");
+        return Failure;
+    }
+    return Success;
+}
+
+/** Callback function called when data is received on the serial port */
+void XBee::uart_read_cb(void)
+{
+    static uint8_t rxstate = WAITING_FOR_START_FRAME;
+    static uint16_t framelen = 0;
+    static uint16_t bytes_read;
+    static uint8_t chksum;
+    static ApiFrame *frame = NULL;
+    static bool last_byte_escaped = false;
+    
+    while (_uart->readable()) {
+        uint8_t data = _uart->getc();
+        
+        if (IS_API2() && rxstate != WAITING_FOR_START_FRAME) {
+            if (last_byte_escaped) {
+                data = data ^ DR_ESCAPE_XOR_BYTE;
+                last_byte_escaped = false;
+            } else if (data == DR_ESCAPE_BYTE) {
+                last_byte_escaped = true;
+                continue;
+            }
+        }
+        
+        switch (rxstate) {
+            case WAITING_FOR_START_FRAME:
+                if (data == DR_START_OF_FRAME)
+                    rxstate = WAITING_FOR_LENGTH_MSB;
+                break;
+                
+            case WAITING_FOR_LENGTH_MSB:
+                framelen = data << 8;
+                rxstate = WAITING_FOR_LENGTH_LSB;
+                break;
+
+            case WAITING_FOR_LENGTH_LSB:
+                framelen |= data;
+                rxstate = WAITING_FOR_PAYLOAD; /* FIXME, if frame is NULL the status should be WAITING */
+                bytes_read = 0;
+                chksum = 0;
+                /* Sanity check that the frame is smaller than... */
+                if (framelen > MAX_FRAME_PAYLOAD_LEN) {
+                    digi_log(LogLevelDebug, "framelen=%d too long\r\n", framelen);
+                    digi_log(LogLevelWarning, "Frame dropped, frame too long. Increase MAX_FRAME_PAYLOAD_LEN define\r\n");
+                    rxstate = WAITING_FOR_START_FRAME;
+                }
+
+                frame = _framebuf.get_next_free_frame();
+                if (frame == NULL) {
+                    /* It's not possible to achive this condition as we discard older frames and only one frame can be used by syncr. commands */
+                    assert(frame != NULL);
+                    rxstate = WAITING_FOR_START_FRAME;
+                } else {
+                    frame->set_data_len(framelen - 1);
+                }
+                break;
+
+            case WAITING_FOR_PAYLOAD:
+                if (!bytes_read)
+                    frame->set_frame_type((ApiFrame::ApiFrameType)data);
+                else {
+                    frame->set_data(data, bytes_read - 1);
+                }
+                chksum += data;
+                bytes_read++;
+                if (bytes_read == framelen)
+                    rxstate = WAITING_FOR_CHECKSUM;
+                break;
+
+            case WAITING_FOR_CHECKSUM:
+                chksum += data;
+                if (chksum == 0xFF) {
+                    /* We got a valid frame!! */
+                    frame->dump();
+                                        
+                    /* If its a _modem status frame, process it to update the status info of the library.
+                     * The frame is also queued to allow processing it other handlers registered.
+                     * Note that radio_status_update() has to be fast to minimize the impact of processing
+                     * the funcion here */
+                    if (frame->get_frame_type() == ApiFrame::AtModemStatus) {
+                        radio_status_update((AtCmdFrame::ModemStatus)frame->get_data_at(0));
+                        if (_initializing)
+                            _framebuf.free_frame(frame);
+                        else
+                            _framebuf.complete_frame(frame);
+                    }
+                    else {
+                        _framebuf.complete_frame(frame);
+                        /* Note, the frame will be released elsewhere, once it has been processed */
+                    }
+                } else {
+                    _framebuf.free_frame(frame);
+                    digi_log(LogLevelWarning, "Checksum error, got %02x, %02x\r\n", data, chksum);
+                }
+                /* Intentional fall-through */
+            default:
+                rxstate = WAITING_FOR_START_FRAME;
+                break;
+        }                
+    }
+    /* TODO, signal the thread processing incoming frames */
+}
+
+/* This is a pure virtual function, but exists here because its called from this class to
+ * to update the status of the object, and can be called before the construction of the 
+ * object has been completed and the virtual functions filled */
+void XBee::radio_status_update(AtCmdFrame::ModemStatus modem_status)
+{
+    UNUSED_PARAMETER(modem_status);
+}
+
+void XBee::set_timeout(uint16_t timeout_ms)
+{
+    this->_timeout_ms = timeout_ms;        
+}
+
+uint16_t XBee::get_timeout(void) const
+{
+    return _timeout_ms;
+}
+
+RadioType XBee::get_radio_type() const
+{
+    return _type;
+}
+
+
+
+/* */
+ApiFrame * XBee::get_this_api_frame(uint8_t id, ApiFrame::ApiFrameType type, 
+                                          ApiFrame::ApiFrameType type2)
+{
+    int const timeout = _timer.read_ms() + _timeout_ms;
+
+    while (_timer.read_ms() < timeout) {
+        ApiFrame * frame = _framebuf.get_next_complete_frame_syncr();
+        if (frame == NULL) {
+            wait_ms(10);
+            continue;
+        }
+
+        if ((frame->get_frame_type() != type) &&
+            (frame->get_frame_type() != type2)) {
+            _framebuf.complete_frame(frame);
+            wait_ms(1);
+            continue;
+        }
+            
+        if (frame->get_data_at(ATCMD_RESP_FRAME_ID_OFFSET) != id) {
+            _framebuf.complete_frame(frame);
+            wait_ms(1);
+            continue;
+        }
+
+        /* frame found */    
+        return frame;
+    }
+    
+    digi_log(LogLevelWarning, "Frame type: %02x, id: %02x, timeout\r\n", (uint8_t)type, id);
+
+    return NULL;
+}
+
+void XBee::send_byte_escaping_if(uint8_t data)
+{
+    if (IS_API2()) {
+        switch (data) {
+            case DR_START_OF_FRAME:
+            case DR_ESCAPE_BYTE:
+            case DR_XON_BYTE:
+            case DR_XOFF_BYTE:
+                _uart->putc(DR_ESCAPE_BYTE);
+                _uart->putc(data ^ DR_ESCAPE_XOR_BYTE);
+                break;
+            default:
+                _uart->putc(data);
+        }
+    } else {
+        _uart->putc(data);
+    }    
+}
+
+void XBee::send_api_frame(ApiFrame *frame)
+{
+    uint8_t chksum;
+    const uint8_t *data;
+    uint16_t bytes_sent = 0, frame_len;
+    
+    frame->dump();
+        
+    frame_len = 1 + frame->get_data_len(); /* frame type + frame payload */
+    data = frame->get_data();
+    
+    /* Send the start of frame delimiter */
+    _uart->putc(DR_START_OF_FRAME);
+    
+    /* Now the length */
+    send_byte_escaping_if((uint8_t)(frame_len >> 8));
+    send_byte_escaping_if((uint8_t)frame_len);
+
+    /* Send the Frame type and then the payload */
+    chksum = (uint8_t)frame->get_frame_type();
+    send_byte_escaping_if(chksum);
+    bytes_sent++;
+
+    /* And now, send the packet payload */
+    while (bytes_sent++ < frame_len) {
+        chksum += *data;
+        send_byte_escaping_if(*data++);
+    }
+            
+    /* And finally send the checksum */
+    send_byte_escaping_if(~chksum);
+}
+  
+/** */        
+RadioStatus XBee::register_frame_handler(FrameHandler *const handler)
+{
+    if (handler != NULL) {
+        for (int i = 0; i < MAX_FRAME_HANDLERS; i++) {
+            if (_fhandlers[i] != NULL)
+                continue;
+            _fhandlers[i] = handler;
+            return Success;
+        }
+    }
+
+    digi_log(LogLevelError, "No more Frame Handlers available. Increase MAX_FRAME_HANDLERS define\r\n");
+    
+    return Failure;
+}     
+
+/** */
+RadioStatus XBee::unregister_frame_handler(FrameHandler *const handler)
+{
+    int i;
+
+    if (handler != NULL) {
+        for (i = 0; i < MAX_FRAME_HANDLERS; i++) {
+            if (_fhandlers[i] == handler)
+                break;
+        }
+        
+        if (i == MAX_FRAME_HANDLERS)
+            return Failure;
+        
+        do {
+            if (i == MAX_FRAME_HANDLERS - 1)
+                _fhandlers[i] = NULL;
+            else
+                _fhandlers[i] = _fhandlers[i + 1];
+        } while (++i < MAX_FRAME_HANDLERS);
+    }
+
+    return Success;
+}
+
+XBee::RadioProtocol XBee::get_radio_protocol(void) const
+{
+    enum HardwareVersion {
+#ifdef EXTRA_XBEE_PROTOCOLS
+        X09_009 = 0x01,
+        X09_019 = 0x02,
+        XH9_009 = 0x03,
+        XH9_019 = 0x04,
+        X24_009 = 0x05,
+        X24_019 = 0x06,
+        X09_001 = 0x07,
+        XH9_001 = 0x08,
+        X08_004 = 0x09,
+        XC09_009 = 0x0A,
+        XC09_038 = 0x0B,
+        X24_038 = 0x0C,
+        X09_009_TX = 0x0D,
+        X09_019_TX = 0x0E,
+        XH9_009_TX = 0x0F,
+        XH9_019_TX = 0x10,
+        X09_001_TX = 0x11,
+        XH9_001_TX = 0x12,
+        XT09B_XXX = 0x13,
+        XT09_XXX = 0x14,
+        XC08_009 = 0x15,
+        XC08_038 = 0x16,
+#endif
+        XB24_AXX_XX = 0x17,
+        XBP24_AXX_XX = 0x18,
+        XB24_BXIX_XXX = 0x19,
+        XBP24_BXIX_XXX = 0x1A,
+#ifdef EXTRA_XBEE_PROTOCOLS
+        XBP09_DXIX_XXX = 0x1B,
+        XBP09_XCXX_XXX = 0x1C,
+        XBP08_DXXX_XXX = 0x1D,
+#endif
+        XBP24B = 0x1E,
+#ifdef EXTRA_XBEE_PROTOCOLS
+        XB24_WF = 0x1F,
+        AMBER_MBUS = 0x20,
+#endif
+        XBP24C = 0x21,
+        XB24C = 0x22,
+#ifdef EXTRA_XBEE_PROTOCOLS
+        XSC_GEN3 = 0x23,
+        SRD_868_GEN3 = 0x24,
+        ABANDONATED = 0x25,
+        SMT_900LP = 0x26,
+        WIFI_ATHEROS = 0x27,
+        SMT_WIFI_ATHEROS = 0x28,
+        SMT_475LP = 0x29,
+        XBEE_CELL_TH = 0x2A,
+        XLR_MODULE = 0x2B,
+        XB900HP_NZ = 0x2C,
+        XBP24C_TH_DIP = 0x2D,
+        XB24C_TH_DIP = 0x2E,
+        XLR_BASEBOARD = 0x2F
+#endif
+    };
+    const bool fw_4_bytes_len = _fw_version > 0x0FFF && _fw_version < 0xFFFF;
+    const uint8_t fw_nibble_3 = (_fw_version >> (4 * 3)) & 0x000F;
+    const uint8_t fw_nibble_1 = (_fw_version >> (4 * 1)) & 0x000F;
+    const uint8_t fw_nibble_0 = (_fw_version >> (4 * 0)) & 0x000F;
+    const uint8_t hw_version_msb = _hw_version >> 8;
+
+    if (hw_version_msb == XB24_AXX_XX || hw_version_msb == XBP24_AXX_XX) {
+#ifdef EXTRA_XBEE_PROTOCOLS
+        if (fw_4_bytes_len && fw_nibble_3 == 8) {
+            return DigiMesh;
+        }
+        return Raw_802_15_4;
+#else
+        if (!(fw_4_bytes_len && fw_nibble_3 == 8)) {
+            return Raw_802_15_4;
+        }
+#endif
+    } else if (hw_version_msb == XB24_BXIX_XXX || hw_version_msb == XBP24_BXIX_XXX) {
+        if (fw_4_bytes_len && ((fw_nibble_3 == 1 && fw_nibble_1 == 2 && fw_nibble_0 == 0) || fw_nibble_3 == 2)) {
+            return ZigBee;
+        }
+#ifdef EXTRA_XBEE_PROTOCOLS
+        if (fw_4_bytes_len && fw_nibble_3 == 3) {
+            return SmartEnergy;
+        }
+        return ZNet;
+    } else if (hw_version_msb == XBP09_DXIX_XXX) {
+        if (fw_4_bytes_len && (fw_nibble_3 == 8 || fw_nibble_1 == 8))  {
+            return DigiMesh;
+        }
+        return DigiPoint;
+    } else if (hw_version_msb == XBP08_DXXX_XXX) {
+        return DigiPoint;
+#endif
+    } else if (hw_version_msb == XBP24B) {
+#ifdef EXTRA_XBEE_PROTOCOLS
+        if (fw_4_bytes_len && fw_nibble_3 == 3) {
+            return SmartEnergy;
+        }
+        return ZigBee;
+#else
+        if (!(fw_4_bytes_len && fw_nibble_3 == 3)) {
+            return ZigBee;
+        }
+#endif
+#ifdef EXTRA_XBEE_PROTOCOLS
+    } else if (hw_version_msb == XB24_WF || hw_version_msb == WIFI_ATHEROS || hw_version_msb == SMT_WIFI_ATHEROS) {
+        return XBeeWiFi;
+#endif
+    } else if (hw_version_msb == XBP24C || hw_version_msb == XB24C) {
+#ifdef EXTRA_XBEE_PROTOCOLS
+        if (fw_4_bytes_len && fw_nibble_3 == 5) {
+            return SmartEnergy;
+        }
+        return ZigBee;
+#else
+        if (!(fw_4_bytes_len && fw_nibble_3 == 5)) {
+            return ZigBee;
+        }
+#endif
+#ifdef EXTRA_XBEE_PROTOCOLS
+    } else if (hw_version_msb == XSC_GEN3 || hw_version_msb == SRD_868_GEN3) {
+        if (fw_4_bytes_len && fw_nibble_3 == 8) {
+            return DigiMesh;
+        } else if (fw_4_bytes_len && fw_nibble_3 == 1) {
+            return DigiPoint;
+        }
+        return None;
+    } else if (hw_version_msb == XBEE_CELL_TH) {
+        return None;
+    } else if (hw_version_msb == XLR_MODULE) {
+        return None;
+    } else if (hw_version_msb == XLR_BASEBOARD) {
+        return None;
+    } else if (hw_version_msb == XB900HP_NZ) {
+        return DigiPoint;
+    }
+#else
+    }
+#endif
+
+    return None;
+}
+
+#define TX_STATUS_OFFSET_ZB     4
+#define TX_STATUS_OFFSET_802    1
+
+TxStatus XBee::send_data(ApiFrame *frame)
+{
+    TxStatus resp = TxStatusTimeout;
+    ApiFrame *resp_frame;
+
+    send_api_frame(frame);
+
+    /* Wait for the transmit status response packet */   
+    resp_frame = get_this_api_frame(frame->get_frame_id(), 
+                    ApiFrame::TxStatusZB, ApiFrame::TxStatus);
+    if (resp_frame == NULL)
+        return resp;
+    
+    uint8_t index = resp_frame->get_frame_type() == ApiFrame::TxStatusZB ?
+            TX_STATUS_OFFSET_ZB : TX_STATUS_OFFSET_802;
+    
+    resp = (TxStatus)resp_frame->get_data_at(index);
+ 
+    /* Once processed, remove the frame from the buffer */
+    _framebuf.free_frame(resp_frame);
+    
+    return resp;
+}
+
+TxStatus XBee::send_data_broadcast(const uint8_t *const data, uint16_t len)
+{
+    const RemoteXBee remoteDevice = RemoteXBee(ADDR64_BROADCAST);
+    return send_data(remoteDevice, data, len);
+}
+
+#if defined(ENABLE_PM_SUPPORT)
+
+RadioStatus XBee::set_pm_control(PmMode mode, PinName on_sleep, PinName sleep_rq)
+{
+    if (on_sleep != NC) {
+        _on_sleep = new InterruptIn(on_sleep);
+    }
+    if (sleep_rq != NC) {
+        _sleep_req = new DigitalOut(sleep_rq);
+    }
+    _pm_mode = mode;
+    /* TODO, set PM mode in the radio */
+    //return 0;
+    return Success;
+}
+
+
+RadioStatus XBee::get_pm_mode(PmMode *mode)
+{
+    *mode = _pm_mode;
+    return Success;
+}
+
+RadioStatus XBee::config_pm_timing(uint32_t before_sleep_ms, uint32_t total_sleep_period_ms)
+{
+    UNUSED_PARAMETER(before_sleep_ms);
+    UNUSED_PARAMETER(total_sleep_period_ms);
+    return Success;
+}
+
+RadioStatus XBee::enter_sleep_mode()
+{
+    if (_sleep_req == NULL)
+        return sleep_now();
+    
+    _sleep_req->write(1);
+    return Success;
+}
+
+void XBee::exit_sleep_mode()
+{
+    /* TODO, check also mode? */
+    if (_sleep_req != NULL)
+        _sleep_req->write(0);
+}
+
+bool XBee::is_sleeping()
+{
+    /* TODO */
+    return true;
+}
+         
+
+
+void XBee::register_wakeup_cb(void (*f)(void))
+{
+    if (_on_sleep == NULL)
+        return;
+    
+    _on_sleep->rise(f);
+}
+
+void XBee::unregister_wakeup_cb()
+{
+    _on_sleep->disable_irq();
+    _on_sleep->rise(NULL);
+}
+
+#endif /* defined(ENABLE_PM_SUPPORT) */
+
+
+uint32_t XBee::process_rx_frames(void)
+{
+    ApiFrame *frame = NULL;
+
+    while ((frame = _framebuf.get_next_complete_frame_app()) != NULL) {
+        for (int i = 0; i < MAX_FRAME_HANDLERS; i++) {
+
+            if (_fhandlers[i] == NULL) {
+                /* No more handlers, break here */
+                break;
+            }
+
+            /* Check if frame and handler match, if not... go for the next one */
+            if (frame->get_frame_type() != _fhandlers[i]->get_type()) {
+                continue;
+            }
+
+            _fhandlers[i]->process_frame_data(frame);
+        }
+            
+        /* Once processed, remove the frame from the buffer */
+        _framebuf.free_frame(frame);
+    }    
+
+    return _framebuf.get_dropped_frames_count();
+}
+
+void XBee::register_modem_status_cb(modem_status_cb_t function)
+{
+    if (_modem_status_handler == NULL) {
+        _modem_status_handler = new FH_ModemStatus();
+        register_frame_handler(_modem_status_handler);
+    }
+    _modem_status_handler->register_modem_status_cb(function);
+}
+
+void XBee::unregister_modem_status_cb()
+{
+    if (_modem_status_handler != NULL) {
+        _modem_status_handler->unregister_modem_status_cb();
+        unregister_frame_handler(_modem_status_handler);
+        delete _modem_status_handler;
+        _modem_status_handler = NULL; /* as delete does not set to NULL */
+    }
+}
+