https://github.com/WebBluetoothCG/demos/pull/42
Dependencies: BLE_API mbed-dev-bin nRF51822
Fork of microbit-dal by
source/drivers/MicroBitRadioDatagram.cpp@74:04376b21995b, 2016-07-21 (annotated)
- Committer:
- fbeaufort
- Date:
- Thu Jul 21 07:19:19 2016 +0000
- Revision:
- 74:04376b21995b
- Parent:
- 1:8aa5cdb4ab67
First commit
Who changed what in which revision?
User | Revision | Line number | New 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 broadcast simple text or binary messages to other micro:bits in the vicinity |
Jonathan Austin |
1:8aa5cdb4ab67 | 33 | * It is envisaged that this would provide the basis for children to experiment with building their own, simple, |
Jonathan Austin |
1:8aa5cdb4ab67 | 34 | * custom protocols. |
Jonathan Austin |
1:8aa5cdb4ab67 | 35 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 36 | * @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 | 37 | * teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place. |
Jonathan Austin |
1:8aa5cdb4ab67 | 38 | * For serious applications, BLE should be considered a substantially more secure alternative. |
Jonathan Austin |
1:8aa5cdb4ab67 | 39 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 40 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 41 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 42 | * Constructor. |
Jonathan Austin |
1:8aa5cdb4ab67 | 43 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 44 | * Creates an instance of a MicroBitRadioDatagram which offers the ability |
Jonathan Austin |
1:8aa5cdb4ab67 | 45 | * to broadcast simple text or binary messages to other micro:bits in the vicinity |
Jonathan Austin |
1:8aa5cdb4ab67 | 46 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 47 | * @param r The underlying radio module used to send and receive data. |
Jonathan Austin |
1:8aa5cdb4ab67 | 48 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 49 | MicroBitRadioDatagram::MicroBitRadioDatagram(MicroBitRadio &r) : radio(r) |
Jonathan Austin |
1:8aa5cdb4ab67 | 50 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 51 | this->rxQueue = NULL; |
Jonathan Austin |
1:8aa5cdb4ab67 | 52 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 53 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 54 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 55 | * Retrieves packet payload data into the given buffer. |
Jonathan Austin |
1:8aa5cdb4ab67 | 56 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 57 | * If a data packet is already available, then it will be returned immediately to the caller. |
Jonathan Austin |
1:8aa5cdb4ab67 | 58 | * If no data is available then MICROBIT_INVALID_PARAMETER is returned. |
Jonathan Austin |
1:8aa5cdb4ab67 | 59 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 60 | * @param buf A pointer to a valid memory location where the received data is to be stored |
Jonathan Austin |
1:8aa5cdb4ab67 | 61 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 62 | * @param len The maximum amount of data that can safely be stored in 'buf' |
Jonathan Austin |
1:8aa5cdb4ab67 | 63 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 64 | * @return The length of the data stored, or MICROBIT_INVALID_PARAMETER if no data is available, or the memory regions provided are invalid. |
Jonathan Austin |
1:8aa5cdb4ab67 | 65 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 66 | int MicroBitRadioDatagram::recv(uint8_t *buf, int len) |
Jonathan Austin |
1:8aa5cdb4ab67 | 67 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 68 | if (buf == NULL || rxQueue == NULL || len < 0) |
Jonathan Austin |
1:8aa5cdb4ab67 | 69 | return MICROBIT_INVALID_PARAMETER; |
Jonathan Austin |
1:8aa5cdb4ab67 | 70 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 71 | // Take the first buffer from the queue. |
Jonathan Austin |
1:8aa5cdb4ab67 | 72 | FrameBuffer *p = rxQueue; |
Jonathan Austin |
1:8aa5cdb4ab67 | 73 | rxQueue = rxQueue->next; |
Jonathan Austin |
1:8aa5cdb4ab67 | 74 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 75 | int l = min(len, p->length - (MICROBIT_RADIO_HEADER_SIZE - 1)); |
Jonathan Austin |
1:8aa5cdb4ab67 | 76 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 77 | // Fill in the buffer provided, if possible. |
Jonathan Austin |
1:8aa5cdb4ab67 | 78 | memcpy(buf, p->payload, l); |
Jonathan Austin |
1:8aa5cdb4ab67 | 79 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 80 | delete p; |
Jonathan Austin |
1:8aa5cdb4ab67 | 81 | return l; |
Jonathan Austin |
1:8aa5cdb4ab67 | 82 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 83 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 84 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 85 | * Retreives packet payload data into the given buffer. |
Jonathan Austin |
1:8aa5cdb4ab67 | 86 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 87 | * If a data packet is already available, then it will be returned immediately to the caller |
Jonathan Austin |
1:8aa5cdb4ab67 | 88 | * in the form of a PacketBuffer. |
Jonathan Austin |
1:8aa5cdb4ab67 | 89 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 90 | * @return the data received, or an empty PacketBuffer if no data is available. |
Jonathan Austin |
1:8aa5cdb4ab67 | 91 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 92 | PacketBuffer MicroBitRadioDatagram::recv() |
Jonathan Austin |
1:8aa5cdb4ab67 | 93 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 94 | if (rxQueue == NULL) |
Jonathan Austin |
1:8aa5cdb4ab67 | 95 | return PacketBuffer::EmptyPacket; |
Jonathan Austin |
1:8aa5cdb4ab67 | 96 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 97 | FrameBuffer *p = rxQueue; |
Jonathan Austin |
1:8aa5cdb4ab67 | 98 | rxQueue = rxQueue->next; |
Jonathan Austin |
1:8aa5cdb4ab67 | 99 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 100 | PacketBuffer packet(p->payload, p->length - (MICROBIT_RADIO_HEADER_SIZE - 1), p->rssi); |
Jonathan Austin |
1:8aa5cdb4ab67 | 101 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 102 | delete p; |
Jonathan Austin |
1:8aa5cdb4ab67 | 103 | return packet; |
Jonathan Austin |
1:8aa5cdb4ab67 | 104 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 105 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 106 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 107 | * Transmits the given buffer onto the broadcast radio. |
Jonathan Austin |
1:8aa5cdb4ab67 | 108 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 109 | * This is a synchronous call that will wait until the transmission of the packet |
Jonathan Austin |
1:8aa5cdb4ab67 | 110 | * has completed before returning. |
Jonathan Austin |
1:8aa5cdb4ab67 | 111 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 112 | * @param buffer The packet contents to transmit. |
Jonathan Austin |
1:8aa5cdb4ab67 | 113 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 114 | * @param len The number of bytes to transmit. |
Jonathan Austin |
1:8aa5cdb4ab67 | 115 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 116 | * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the buffer is invalid, |
Jonathan Austin |
1:8aa5cdb4ab67 | 117 | * or the number of bytes to transmit is greater than `MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE`. |
Jonathan Austin |
1:8aa5cdb4ab67 | 118 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 119 | int MicroBitRadioDatagram::send(uint8_t *buffer, int len) |
Jonathan Austin |
1:8aa5cdb4ab67 | 120 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 121 | if (buffer == NULL || len < 0 || len > MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE - 1) |
Jonathan Austin |
1:8aa5cdb4ab67 | 122 | return MICROBIT_INVALID_PARAMETER; |
Jonathan Austin |
1:8aa5cdb4ab67 | 123 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 124 | FrameBuffer buf; |
Jonathan Austin |
1:8aa5cdb4ab67 | 125 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 126 | buf.length = len + MICROBIT_RADIO_HEADER_SIZE - 1; |
Jonathan Austin |
1:8aa5cdb4ab67 | 127 | buf.version = 1; |
Jonathan Austin |
1:8aa5cdb4ab67 | 128 | buf.group = 0; |
Jonathan Austin |
1:8aa5cdb4ab67 | 129 | buf.protocol = MICROBIT_RADIO_PROTOCOL_DATAGRAM; |
Jonathan Austin |
1:8aa5cdb4ab67 | 130 | memcpy(buf.payload, buffer, len); |
Jonathan Austin |
1:8aa5cdb4ab67 | 131 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 132 | return radio.send(&buf); |
Jonathan Austin |
1:8aa5cdb4ab67 | 133 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 134 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 135 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 136 | * Transmits the given string onto the broadcast radio. |
Jonathan Austin |
1:8aa5cdb4ab67 | 137 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 138 | * This is a synchronous call that will wait until the transmission of the packet |
Jonathan Austin |
1:8aa5cdb4ab67 | 139 | * has completed before returning. |
Jonathan Austin |
1:8aa5cdb4ab67 | 140 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 141 | * @param data The packet contents to transmit. |
Jonathan Austin |
1:8aa5cdb4ab67 | 142 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 143 | * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the buffer is invalid, |
Jonathan Austin |
1:8aa5cdb4ab67 | 144 | * or the number of bytes to transmit is greater than `MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE`. |
Jonathan Austin |
1:8aa5cdb4ab67 | 145 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 146 | int MicroBitRadioDatagram::send(PacketBuffer data) |
Jonathan Austin |
1:8aa5cdb4ab67 | 147 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 148 | return send((uint8_t *)data.getBytes(), data.length()); |
Jonathan Austin |
1:8aa5cdb4ab67 | 149 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 150 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 151 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 152 | * Transmits the given string onto the broadcast radio. |
Jonathan Austin |
1:8aa5cdb4ab67 | 153 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 154 | * This is a synchronous call that will wait until the transmission of the packet |
Jonathan Austin |
1:8aa5cdb4ab67 | 155 | * has completed before returning. |
Jonathan Austin |
1:8aa5cdb4ab67 | 156 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 157 | * @param data The packet contents to transmit. |
Jonathan Austin |
1:8aa5cdb4ab67 | 158 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 159 | * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the buffer is invalid, |
Jonathan Austin |
1:8aa5cdb4ab67 | 160 | * or the number of bytes to transmit is greater than `MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE`. |
Jonathan Austin |
1:8aa5cdb4ab67 | 161 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 162 | int MicroBitRadioDatagram::send(ManagedString data) |
Jonathan Austin |
1:8aa5cdb4ab67 | 163 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 164 | return send((uint8_t *)data.toCharArray(), data.length()); |
Jonathan Austin |
1:8aa5cdb4ab67 | 165 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 166 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 167 | /** |
Jonathan Austin |
1:8aa5cdb4ab67 | 168 | * Protocol handler callback. This is called when the radio receives a packet marked as a datagram. |
Jonathan Austin |
1:8aa5cdb4ab67 | 169 | * |
Jonathan Austin |
1:8aa5cdb4ab67 | 170 | * This function process this packet, and queues it for user reception. |
Jonathan Austin |
1:8aa5cdb4ab67 | 171 | */ |
Jonathan Austin |
1:8aa5cdb4ab67 | 172 | void MicroBitRadioDatagram::packetReceived() |
Jonathan Austin |
1:8aa5cdb4ab67 | 173 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 174 | FrameBuffer *packet = radio.recv(); |
Jonathan Austin |
1:8aa5cdb4ab67 | 175 | int queueDepth = 0; |
Jonathan Austin |
1:8aa5cdb4ab67 | 176 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 177 | // We add to the tail of the queue to preserve causal ordering. |
Jonathan Austin |
1:8aa5cdb4ab67 | 178 | packet->next = NULL; |
Jonathan Austin |
1:8aa5cdb4ab67 | 179 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 180 | if (rxQueue == NULL) |
Jonathan Austin |
1:8aa5cdb4ab67 | 181 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 182 | rxQueue = packet; |
Jonathan Austin |
1:8aa5cdb4ab67 | 183 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 184 | else |
Jonathan Austin |
1:8aa5cdb4ab67 | 185 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 186 | FrameBuffer *p = rxQueue; |
Jonathan Austin |
1:8aa5cdb4ab67 | 187 | while (p->next != NULL) |
Jonathan Austin |
1:8aa5cdb4ab67 | 188 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 189 | p = p->next; |
Jonathan Austin |
1:8aa5cdb4ab67 | 190 | queueDepth++; |
Jonathan Austin |
1:8aa5cdb4ab67 | 191 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 192 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 193 | if (queueDepth >= MICROBIT_RADIO_MAXIMUM_RX_BUFFERS) |
Jonathan Austin |
1:8aa5cdb4ab67 | 194 | { |
Jonathan Austin |
1:8aa5cdb4ab67 | 195 | delete packet; |
Jonathan Austin |
1:8aa5cdb4ab67 | 196 | return; |
Jonathan Austin |
1:8aa5cdb4ab67 | 197 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 198 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 199 | p->next = packet; |
Jonathan Austin |
1:8aa5cdb4ab67 | 200 | } |
Jonathan Austin |
1:8aa5cdb4ab67 | 201 | |
Jonathan Austin |
1:8aa5cdb4ab67 | 202 | MicroBitEvent(MICROBIT_ID_RADIO, MICROBIT_RADIO_EVT_DATAGRAM); |
Jonathan Austin |
1:8aa5cdb4ab67 | 203 | } |