Diff: inc/drivers/MicroBitRadioDatagram.h

Revision:

1:8aa5cdb4ab67

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/inc/drivers/MicroBitRadioDatagram.h	Thu Apr 07 01:33:22 2016 +0100
@@ -0,0 +1,135 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 British Broadcasting Corporation.
+This software is provided by Lancaster University by arrangement with the BBC.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+*/
+
+#ifndef MICROBIT_RADIO_DATAGRAM_H
+#define MICROBIT_RADIO_DATAGRAM_H
+
+#include "mbed.h"
+#include "MicroBitConfig.h"
+#include "MicroBitRadio.h"
+#include "ManagedString.h"
+
+/**
+  * Provides a simple broadcast radio abstraction, built upon the raw nrf51822 RADIO module.
+  *
+  * This class provides the ability to broadcast simple text or binary messages to other micro:bits in the vicinity
+  * It is envisaged that this would provide the basis for children to experiment with building their own, simple,
+  * custom protocols.
+  *
+  * @note This API does not contain any form of encryption, authentication or authorisation. Its purpose is solely for use as a
+  * teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place.
+  * For serious applications, BLE should be considered a substantially more secure alternative.
+  */
+class MicroBitRadioDatagram
+{
+    MicroBitRadio   &radio;     // The underlying radio module used to send and receive data.
+    FrameBuffer     *rxQueue;   // A linear list of incoming packets, queued awaiting processing.
+
+    public:
+
+    /**
+      * Constructor.
+      *
+      * Creates an instance of a MicroBitRadioDatagram which offers the ability
+      * to broadcast simple text or binary messages to other micro:bits in the vicinity
+      *
+      * @param r The underlying radio module used to send and receive data.
+      */
+    MicroBitRadioDatagram(MicroBitRadio &r);
+
+    /**
+      * Retrieves packet payload data into the given buffer.
+      *
+      * If a data packet is already available, then it will be returned immediately to the caller.
+      * If no data is available then MICROBIT_INVALID_PARAMETER is returned.
+      *
+      * @param buf A pointer to a valid memory location where the received data is to be stored
+      *
+      * @param len The maximum amount of data that can safely be stored in 'buf'
+      *
+      * @return The length of the data stored, or MICROBIT_INVALID_PARAMETER if no data is available, or the memory regions provided are invalid.
+      */
+    int recv(uint8_t *buf, int len);
+
+    /**
+      * Retreives packet payload data into the given buffer.
+      *
+      * If a data packet is already available, then it will be returned immediately to the caller
+      * in the form of a PacketBuffer.
+      *
+      * @return the data received, or an empty PacketBuffer if no data is available.
+      */
+    PacketBuffer recv();
+
+    /**
+      * Transmits the given buffer onto the broadcast radio.
+      *
+      * This is a synchronous call that will wait until the transmission of the packet
+      * has completed before returning.
+      *
+      * @param buffer The packet contents to transmit.
+      *
+      * @param len The number of bytes to transmit.
+      *
+      * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the buffer is invalid,
+      *         or the number of bytes to transmit is greater than `MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE`.
+      */
+    int send(uint8_t *buffer, int len);
+
+    /**
+      * Transmits the given string onto the broadcast radio.
+      *
+      * This is a synchronous call that will wait until the transmission of the packet
+      * has completed before returning.
+      *
+      * @param data The packet contents to transmit.
+      *
+      * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the buffer is invalid,
+      *         or the number of bytes to transmit is greater than `MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE`.
+      */
+    int send(PacketBuffer data);
+
+    /**
+      * Transmits the given string onto the broadcast radio.
+      *
+      * This is a synchronous call that will wait until the transmission of the packet
+      * has completed before returning.
+      *
+      * @param data The packet contents to transmit.
+      *
+      * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the buffer is invalid,
+      *         or the number of bytes to transmit is greater than `MICROBIT_RADIO_MAX_PACKET_SIZE + MICROBIT_RADIO_HEADER_SIZE`.
+      */
+    int send(ManagedString data);
+
+    /**
+      * Protocol handler callback. This is called when the radio receives a packet marked as a datagram.
+      *
+      * This function process this packet, and queues it for user reception.
+      */
+    void packetReceived();
+};
+
+#endif