Solution for Bluetooth SIG hands-on training course
Dependencies: BLE_API mbed-dev-bin nRF51822-bluetooth-mdw
Fork of microbit-dal-bluetooth-mdw_starter by
MicroBitRadioEvent.cpp
00001 /* 00002 The MIT License (MIT) 00003 00004 Copyright (c) 2016 British Broadcasting Corporation. 00005 This software is provided by Lancaster University by arrangement with the BBC. 00006 00007 Permission is hereby granted, free of charge, to any person obtaining a 00008 copy of this software and associated documentation files (the "Software"), 00009 to deal in the Software without restriction, including without limitation 00010 the rights to use, copy, modify, merge, publish, distribute, sublicense, 00011 and/or sell copies of the Software, and to permit persons to whom the 00012 Software is furnished to do so, subject to the following conditions: 00013 00014 The above copyright notice and this permission notice shall be included in 00015 all copies or substantial portions of the Software. 00016 00017 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 00018 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00019 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 00020 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 00021 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 00022 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 00023 DEALINGS IN THE SOFTWARE. 00024 */ 00025 00026 #include "MicroBitConfig.h" 00027 #include "MicroBitRadio.h" 00028 00029 /** 00030 * Provides a simple broadcast radio abstraction, built upon the raw nrf51822 RADIO module. 00031 * 00032 * This class provides the ability to extend the micro:bit's default EventModel to other micro:bits in the vicinity, 00033 * in a very similar way to the MicroBitEventService for BLE interfaces. 00034 * 00035 * It is envisaged that this would provide the basis for children to experiment with building their own, simple, 00036 * custom asynchronous events and actions. 00037 * 00038 * @note This API does not contain any form of encryption, authentication or authorisation. Its purpose is solely for use as a 00039 * teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place. 00040 * For serious applications, BLE should be considered a substantially more secure alternative. 00041 */ 00042 00043 /** 00044 * Constructor. 00045 * 00046 * Creates an instance of MicroBitRadioEvent which offers the ability to extend 00047 * the micro:bit's default EventModel to other micro:bits in the vicinity. 00048 * 00049 * @param r The underlying radio module used to send and receive data. 00050 */ 00051 MicroBitRadioEvent::MicroBitRadioEvent(MicroBitRadio &r) : radio(r) 00052 { 00053 this->suppressForwarding = false; 00054 } 00055 00056 /** 00057 * Associates the given event with the radio channel. 00058 * 00059 * Once registered, all events matching the given registration sent to this micro:bit's 00060 * default EventModel will be automatically retransmitted on the radio. 00061 * 00062 * @param id The id of the event to register. 00063 * 00064 * @param value the value of the event to register. 00065 * 00066 * @return MICROBIT_OK on success, or MICROBIT_NO_RESOURCES if no default EventModel is available. 00067 * 00068 * @note The wildcards MICROBIT_ID_ANY and MICROBIT_EVT_ANY can also be in place of the 00069 * id and value fields. 00070 */ 00071 int MicroBitRadioEvent::listen(uint16_t id, uint16_t value) 00072 { 00073 if (EventModel::defaultEventBus) 00074 return listen(id, value, *EventModel::defaultEventBus); 00075 00076 return MICROBIT_NO_RESOURCES; 00077 } 00078 00079 /** 00080 * Associates the given event with the radio channel. 00081 * 00082 * Once registered, all events matching the given registration sent to the given 00083 * EventModel will be automatically retransmitted on the radio. 00084 * 00085 * @param id The id of the events to register. 00086 * 00087 * @param value the value of the event to register. 00088 * 00089 * @param eventBus The EventModel to listen for events on. 00090 * 00091 * @return MICROBIT_OK on success. 00092 * 00093 * @note The wildcards MICROBIT_ID_ANY and MICROBIT_EVT_ANY can also be in place of the 00094 * id and value fields. 00095 */ 00096 int MicroBitRadioEvent::listen(uint16_t id, uint16_t value, EventModel &eventBus) 00097 { 00098 return eventBus.listen(id, value, this, &MicroBitRadioEvent::eventReceived, MESSAGE_BUS_LISTENER_IMMEDIATE); 00099 } 00100 00101 /** 00102 * Disassociates the given event with the radio channel. 00103 * 00104 * @param id The id of the events to deregister. 00105 * 00106 * @param value The value of the event to deregister. 00107 * 00108 * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the default message bus does not exist. 00109 * 00110 * @note MICROBIT_EVT_ANY can be used to deregister all event values matching the given id. 00111 */ 00112 int MicroBitRadioEvent::ignore(uint16_t id, uint16_t value) 00113 { 00114 if (EventModel::defaultEventBus) 00115 return ignore(id, value, *EventModel::defaultEventBus); 00116 00117 return MICROBIT_INVALID_PARAMETER; 00118 } 00119 00120 /** 00121 * Disassociates the given events with the radio channel. 00122 * 00123 * @param id The id of the events to deregister. 00124 * 00125 * @param value The value of the event to deregister. 00126 * 00127 * @param eventBus The EventModel to deregister on. 00128 * 00129 * @return MICROBIT_OK on success. 00130 * 00131 * @note MICROBIT_EVT_ANY can be used to deregister all event values matching the given id. 00132 */ 00133 int MicroBitRadioEvent::ignore(uint16_t id, uint16_t value, EventModel &eventBus) 00134 { 00135 return eventBus.ignore(id, value, this, &MicroBitRadioEvent::eventReceived); 00136 } 00137 00138 00139 /** 00140 * Protocol handler callback. This is called when the radio receives a packet marked as using the event protocol. 00141 * 00142 * This function process this packet, and fires the event contained inside onto the default EventModel. 00143 */ 00144 void MicroBitRadioEvent::packetReceived() 00145 { 00146 FrameBuffer *p = radio.recv(); 00147 MicroBitEvent *e = (MicroBitEvent *) p->payload; 00148 00149 suppressForwarding = true; 00150 e->fire(); 00151 suppressForwarding = false; 00152 00153 delete p; 00154 } 00155 00156 /** 00157 * Event handler callback. This is called whenever an event is received matching one of those registered through 00158 * the registerEvent() method described above. Upon receiving such an event, it is wrapped into 00159 * a radio packet and transmitted to any other micro:bits in the same group. 00160 */ 00161 void MicroBitRadioEvent::eventReceived(MicroBitEvent e) 00162 { 00163 if(suppressForwarding) 00164 return; 00165 00166 FrameBuffer buf; 00167 00168 buf.length = sizeof(MicroBitEvent) + MICROBIT_RADIO_HEADER_SIZE - 1; 00169 buf.version = 1; 00170 buf.group = 0; 00171 buf.protocol = MICROBIT_RADIO_PROTOCOL_EVENTBUS; 00172 memcpy(buf.payload, (const uint8_t *)&e, sizeof(MicroBitEvent)); 00173 00174 radio.send(&buf); 00175 }
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