Cefn Hoile / microbit-dal

Attempting to publish a tree

Dependencies:   BLE_API mbed-dev-bin nRF51822

Fork of microbit-dal by Lancaster University

source/drivers/MicroBitRadioEvent.cpp@18:ce4dd8fcdf4f, 2016-06-01 (annotated)

Committer:
cefn
Date:
Wed Jun 01 17:43:26 2016 +0000
Revision:
18:ce4dd8fcdf4f
Parent:
1:8aa5cdb4ab67 
Attempting to publish a tree

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Jonathan Austin 1:8aa5cdb4ab67 1 /*
Jonathan Austin 1:8aa5cdb4ab67 2 The MIT License (MIT)
Jonathan Austin 1:8aa5cdb4ab67 3
Jonathan Austin 1:8aa5cdb4ab67 4 Copyright (c) 2016 British Broadcasting Corporation.
Jonathan Austin 1:8aa5cdb4ab67 5 This software is provided by Lancaster University by arrangement with the BBC.
Jonathan Austin 1:8aa5cdb4ab67 6
Jonathan Austin 1:8aa5cdb4ab67 7 Permission is hereby granted, free of charge, to any person obtaining a
Jonathan Austin 1:8aa5cdb4ab67 8 copy of this software and associated documentation files (the "Software"),
Jonathan Austin 1:8aa5cdb4ab67 9 to deal in the Software without restriction, including without limitation
Jonathan Austin 1:8aa5cdb4ab67 10 the rights to use, copy, modify, merge, publish, distribute, sublicense,
Jonathan Austin 1:8aa5cdb4ab67 11 and/or sell copies of the Software, and to permit persons to whom the
Jonathan Austin 1:8aa5cdb4ab67 12 Software is furnished to do so, subject to the following conditions:
Jonathan Austin 1:8aa5cdb4ab67 13
Jonathan Austin 1:8aa5cdb4ab67 14 The above copyright notice and this permission notice shall be included in
Jonathan Austin 1:8aa5cdb4ab67 15 all copies or substantial portions of the Software.
Jonathan Austin 1:8aa5cdb4ab67 16
Jonathan Austin 1:8aa5cdb4ab67 17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Jonathan Austin 1:8aa5cdb4ab67 18 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Jonathan Austin 1:8aa5cdb4ab67 19 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
Jonathan Austin 1:8aa5cdb4ab67 20 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 21 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
Jonathan Austin 1:8aa5cdb4ab67 22 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
Jonathan Austin 1:8aa5cdb4ab67 23 DEALINGS IN THE SOFTWARE.
Jonathan Austin 1:8aa5cdb4ab67 24 */
Jonathan Austin 1:8aa5cdb4ab67 25
Jonathan Austin 1:8aa5cdb4ab67 26 #include "MicroBitConfig.h"
Jonathan Austin 1:8aa5cdb4ab67 27 #include "MicroBitRadio.h"
Jonathan Austin 1:8aa5cdb4ab67 28
Jonathan Austin 1:8aa5cdb4ab67 29 /**
Jonathan Austin 1:8aa5cdb4ab67 30 * Provides a simple broadcast radio abstraction, built upon the raw nrf51822 RADIO module.
Jonathan Austin 1:8aa5cdb4ab67 31 *
Jonathan Austin 1:8aa5cdb4ab67 32 * This class provides the ability to extend the micro:bit's default EventModel to other micro:bits in the vicinity,
Jonathan Austin 1:8aa5cdb4ab67 33 * in a very similar way to the MicroBitEventService for BLE interfaces.
Jonathan Austin 1:8aa5cdb4ab67 34 *
Jonathan Austin 1:8aa5cdb4ab67 35 * It is envisaged that this would provide the basis for children to experiment with building their own, simple,
Jonathan Austin 1:8aa5cdb4ab67 36 * custom asynchronous events and actions.
Jonathan Austin 1:8aa5cdb4ab67 37 *
Jonathan Austin 1:8aa5cdb4ab67 38 * @note This API does not contain any form of encryption, authentication or authorisation. Its purpose is solely for use as a
Jonathan Austin 1:8aa5cdb4ab67 39 * teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place.
Jonathan Austin 1:8aa5cdb4ab67 40 * For serious applications, BLE should be considered a substantially more secure alternative.
Jonathan Austin 1:8aa5cdb4ab67 41 */
Jonathan Austin 1:8aa5cdb4ab67 42
Jonathan Austin 1:8aa5cdb4ab67 43 /**
Jonathan Austin 1:8aa5cdb4ab67 44 * Constructor.
Jonathan Austin 1:8aa5cdb4ab67 45 *
Jonathan Austin 1:8aa5cdb4ab67 46 * Creates an instance of MicroBitRadioEvent which offers the ability to extend
Jonathan Austin 1:8aa5cdb4ab67 47 * the micro:bit's default EventModel to other micro:bits in the vicinity.
Jonathan Austin 1:8aa5cdb4ab67 48 *
Jonathan Austin 1:8aa5cdb4ab67 49 * @param r The underlying radio module used to send and receive data.
Jonathan Austin 1:8aa5cdb4ab67 50 */
Jonathan Austin 1:8aa5cdb4ab67 51 MicroBitRadioEvent::MicroBitRadioEvent(MicroBitRadio &r) : radio(r)
Jonathan Austin 1:8aa5cdb4ab67 52 {
Jonathan Austin 1:8aa5cdb4ab67 53 this->suppressForwarding = false;
Jonathan Austin 1:8aa5cdb4ab67 54 }
Jonathan Austin 1:8aa5cdb4ab67 55
Jonathan Austin 1:8aa5cdb4ab67 56 /**
Jonathan Austin 1:8aa5cdb4ab67 57 * Associates the given event with the radio channel.
Jonathan Austin 1:8aa5cdb4ab67 58 *
Jonathan Austin 1:8aa5cdb4ab67 59 * Once registered, all events matching the given registration sent to this micro:bit's
Jonathan Austin 1:8aa5cdb4ab67 60 * default EventModel will be automatically retransmitted on the radio.
Jonathan Austin 1:8aa5cdb4ab67 61 *
Jonathan Austin 1:8aa5cdb4ab67 62 * @param id The id of the event to register.
Jonathan Austin 1:8aa5cdb4ab67 63 *
Jonathan Austin 1:8aa5cdb4ab67 64 * @param value the value of the event to register.
Jonathan Austin 1:8aa5cdb4ab67 65 *
Jonathan Austin 1:8aa5cdb4ab67 66 * @return MICROBIT_OK on success, or MICROBIT_NO_RESOURCES if no default EventModel is available.
Jonathan Austin 1:8aa5cdb4ab67 67 *
Jonathan Austin 1:8aa5cdb4ab67 68 * @note The wildcards MICROBIT_ID_ANY and MICROBIT_EVT_ANY can also be in place of the
Jonathan Austin 1:8aa5cdb4ab67 69 * id and value fields.
Jonathan Austin 1:8aa5cdb4ab67 70 */
Jonathan Austin 1:8aa5cdb4ab67 71 int MicroBitRadioEvent::listen(uint16_t id, uint16_t value)
Jonathan Austin 1:8aa5cdb4ab67 72 {
Jonathan Austin 1:8aa5cdb4ab67 73 if (EventModel::defaultEventBus)
Jonathan Austin 1:8aa5cdb4ab67 74 return listen(id, value, *EventModel::defaultEventBus);
Jonathan Austin 1:8aa5cdb4ab67 75
Jonathan Austin 1:8aa5cdb4ab67 76 return MICROBIT_NO_RESOURCES;
Jonathan Austin 1:8aa5cdb4ab67 77 }
Jonathan Austin 1:8aa5cdb4ab67 78
Jonathan Austin 1:8aa5cdb4ab67 79 /**
Jonathan Austin 1:8aa5cdb4ab67 80 * Associates the given event with the radio channel.
Jonathan Austin 1:8aa5cdb4ab67 81 *
Jonathan Austin 1:8aa5cdb4ab67 82 * Once registered, all events matching the given registration sent to the given
Jonathan Austin 1:8aa5cdb4ab67 83 * EventModel will be automatically retransmitted on the radio.
Jonathan Austin 1:8aa5cdb4ab67 84 *
Jonathan Austin 1:8aa5cdb4ab67 85 * @param id The id of the events to register.
Jonathan Austin 1:8aa5cdb4ab67 86 *
Jonathan Austin 1:8aa5cdb4ab67 87 * @param value the value of the event to register.
Jonathan Austin 1:8aa5cdb4ab67 88 *
Jonathan Austin 1:8aa5cdb4ab67 89 * @param eventBus The EventModel to listen for events on.
Jonathan Austin 1:8aa5cdb4ab67 90 *
Jonathan Austin 1:8aa5cdb4ab67 91 * @return MICROBIT_OK on success.
Jonathan Austin 1:8aa5cdb4ab67 92 *
Jonathan Austin 1:8aa5cdb4ab67 93 * @note The wildcards MICROBIT_ID_ANY and MICROBIT_EVT_ANY can also be in place of the
Jonathan Austin 1:8aa5cdb4ab67 94 * id and value fields.
Jonathan Austin 1:8aa5cdb4ab67 95 */
Jonathan Austin 1:8aa5cdb4ab67 96 int MicroBitRadioEvent::listen(uint16_t id, uint16_t value, EventModel &eventBus)
Jonathan Austin 1:8aa5cdb4ab67 97 {
Jonathan Austin 1:8aa5cdb4ab67 98 return eventBus.listen(id, value, this, &MicroBitRadioEvent::eventReceived, MESSAGE_BUS_LISTENER_IMMEDIATE);
Jonathan Austin 1:8aa5cdb4ab67 99 }
Jonathan Austin 1:8aa5cdb4ab67 100
Jonathan Austin 1:8aa5cdb4ab67 101 /**
Jonathan Austin 1:8aa5cdb4ab67 102 * Disassociates the given event with the radio channel.
Jonathan Austin 1:8aa5cdb4ab67 103 *
Jonathan Austin 1:8aa5cdb4ab67 104 * @param id The id of the events to deregister.
Jonathan Austin 1:8aa5cdb4ab67 105 *
Jonathan Austin 1:8aa5cdb4ab67 106 * @param value The value of the event to deregister.
Jonathan Austin 1:8aa5cdb4ab67 107 *
Jonathan Austin 1:8aa5cdb4ab67 108 * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the default message bus does not exist.
Jonathan Austin 1:8aa5cdb4ab67 109 *
Jonathan Austin 1:8aa5cdb4ab67 110 * @note MICROBIT_EVT_ANY can be used to deregister all event values matching the given id.
Jonathan Austin 1:8aa5cdb4ab67 111 */
Jonathan Austin 1:8aa5cdb4ab67 112 int MicroBitRadioEvent::ignore(uint16_t id, uint16_t value)
Jonathan Austin 1:8aa5cdb4ab67 113 {
Jonathan Austin 1:8aa5cdb4ab67 114 if (EventModel::defaultEventBus)
Jonathan Austin 1:8aa5cdb4ab67 115 return ignore(id, value, *EventModel::defaultEventBus);
Jonathan Austin 1:8aa5cdb4ab67 116
Jonathan Austin 1:8aa5cdb4ab67 117 return MICROBIT_INVALID_PARAMETER;
Jonathan Austin 1:8aa5cdb4ab67 118 }
Jonathan Austin 1:8aa5cdb4ab67 119
Jonathan Austin 1:8aa5cdb4ab67 120 /**
Jonathan Austin 1:8aa5cdb4ab67 121 * Disassociates the given events with the radio channel.
Jonathan Austin 1:8aa5cdb4ab67 122 *
Jonathan Austin 1:8aa5cdb4ab67 123 * @param id The id of the events to deregister.
Jonathan Austin 1:8aa5cdb4ab67 124 *
Jonathan Austin 1:8aa5cdb4ab67 125 * @param value The value of the event to deregister.
Jonathan Austin 1:8aa5cdb4ab67 126 *
Jonathan Austin 1:8aa5cdb4ab67 127 * @param eventBus The EventModel to deregister on.
Jonathan Austin 1:8aa5cdb4ab67 128 *
Jonathan Austin 1:8aa5cdb4ab67 129 * @return MICROBIT_OK on success.
Jonathan Austin 1:8aa5cdb4ab67 130 *
Jonathan Austin 1:8aa5cdb4ab67 131 * @note MICROBIT_EVT_ANY can be used to deregister all event values matching the given id.
Jonathan Austin 1:8aa5cdb4ab67 132 */
Jonathan Austin 1:8aa5cdb4ab67 133 int MicroBitRadioEvent::ignore(uint16_t id, uint16_t value, EventModel &eventBus)
Jonathan Austin 1:8aa5cdb4ab67 134 {
Jonathan Austin 1:8aa5cdb4ab67 135 return eventBus.ignore(id, value, this, &MicroBitRadioEvent::eventReceived);
Jonathan Austin 1:8aa5cdb4ab67 136 }
Jonathan Austin 1:8aa5cdb4ab67 137
Jonathan Austin 1:8aa5cdb4ab67 138
Jonathan Austin 1:8aa5cdb4ab67 139 /**
Jonathan Austin 1:8aa5cdb4ab67 140 * Protocol handler callback. This is called when the radio receives a packet marked as using the event protocol.
Jonathan Austin 1:8aa5cdb4ab67 141 *
Jonathan Austin 1:8aa5cdb4ab67 142 * This function process this packet, and fires the event contained inside onto the default EventModel.
Jonathan Austin 1:8aa5cdb4ab67 143 */
Jonathan Austin 1:8aa5cdb4ab67 144 void MicroBitRadioEvent::packetReceived()
Jonathan Austin 1:8aa5cdb4ab67 145 {
Jonathan Austin 1:8aa5cdb4ab67 146 FrameBuffer *p = radio.recv();
Jonathan Austin 1:8aa5cdb4ab67 147 MicroBitEvent *e = (MicroBitEvent *) p->payload;
Jonathan Austin 1:8aa5cdb4ab67 148
Jonathan Austin 1:8aa5cdb4ab67 149 suppressForwarding = true;
Jonathan Austin 1:8aa5cdb4ab67 150 e->fire();
Jonathan Austin 1:8aa5cdb4ab67 151 suppressForwarding = false;
Jonathan Austin 1:8aa5cdb4ab67 152
Jonathan Austin 1:8aa5cdb4ab67 153 delete p;
Jonathan Austin 1:8aa5cdb4ab67 154 }
Jonathan Austin 1:8aa5cdb4ab67 155
Jonathan Austin 1:8aa5cdb4ab67 156 /**
Jonathan Austin 1:8aa5cdb4ab67 157 * Event handler callback. This is called whenever an event is received matching one of those registered through
Jonathan Austin 1:8aa5cdb4ab67 158 * the registerEvent() method described above. Upon receiving such an event, it is wrapped into
Jonathan Austin 1:8aa5cdb4ab67 159 * a radio packet and transmitted to any other micro:bits in the same group.
Jonathan Austin 1:8aa5cdb4ab67 160 */
Jonathan Austin 1:8aa5cdb4ab67 161 void MicroBitRadioEvent::eventReceived(MicroBitEvent e)
Jonathan Austin 1:8aa5cdb4ab67 162 {
Jonathan Austin 1:8aa5cdb4ab67 163 if(suppressForwarding)
Jonathan Austin 1:8aa5cdb4ab67 164 return;
Jonathan Austin 1:8aa5cdb4ab67 165
Jonathan Austin 1:8aa5cdb4ab67 166 FrameBuffer buf;
Jonathan Austin 1:8aa5cdb4ab67 167
Jonathan Austin 1:8aa5cdb4ab67 168 buf.length = sizeof(MicroBitEvent) + MICROBIT_RADIO_HEADER_SIZE - 1;
Jonathan Austin 1:8aa5cdb4ab67 169 buf.version = 1;
Jonathan Austin 1:8aa5cdb4ab67 170 buf.group = 0;
Jonathan Austin 1:8aa5cdb4ab67 171 buf.protocol = MICROBIT_RADIO_PROTOCOL_EVENTBUS;
Jonathan Austin 1:8aa5cdb4ab67 172 memcpy(buf.payload, (const uint8_t *)&e, sizeof(MicroBitEvent));
Jonathan Austin 1:8aa5cdb4ab67 173
Jonathan Austin 1:8aa5cdb4ab67 174 radio.send(&buf);
Jonathan Austin 1:8aa5cdb4ab67 175 }