Diff: source/bluetooth/MicroBitEventService.cpp

Revision:

1:8aa5cdb4ab67

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/bluetooth/MicroBitEventService.cpp	Thu Apr 07 01:33:22 2016 +0100
@@ -0,0 +1,188 @@
+/*
+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.
+*/
+
+/**
+  * Class definition for a MicroBit BLE Event Service.
+  * Provides a BLE gateway onto an Event Model.
+  */
+
+#include "MicroBitConfig.h"
+#include "MicroBitEventService.h"
+#include "ble/UUID.h"
+#include "ExternalEvents.h"
+#include "MicroBitFiber.h"
+
+/**
+  * Constructor.
+  * Create a representation of the EventService
+  * @param _ble The instance of a BLE device that we're running on.
+  * @param _messageBus An instance of an EventModel which events will be mirrored from.
+  */
+MicroBitEventService::MicroBitEventService(BLEDevice &_ble, EventModel &_messageBus) :
+        ble(_ble),messageBus(_messageBus)
+{
+    GattCharacteristic  microBitEventCharacteristic(MicroBitEventServiceMicroBitEventCharacteristicUUID, (uint8_t *)&microBitEventBuffer, 0, sizeof(EventServiceEvent),
+    GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
+
+    GattCharacteristic  clientEventCharacteristic(MicroBitEventServiceClientEventCharacteristicUUID, (uint8_t *)&clientEventBuffer, 0, sizeof(EventServiceEvent),
+    GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE);
+
+    GattCharacteristic  clientRequirementsCharacteristic(MicroBitEventServiceClientRequirementsCharacteristicUUID, (uint8_t *)&clientRequirementsBuffer, 0, sizeof(EventServiceEvent), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE);
+
+    microBitRequirementsCharacteristic = new GattCharacteristic(MicroBitEventServiceMicroBitRequirementsCharacteristicUUID, (uint8_t *)&microBitRequirementsBuffer, 0, sizeof(EventServiceEvent), GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);
+
+    microBitRequirementsCharacteristic->setReadAuthorizationCallback(this, &MicroBitEventService::onRequirementsRead);
+
+    clientEventBuffer.type = 0x00;
+    clientEventBuffer.reason = 0x00;
+
+    microBitEventBuffer = microBitRequirementsBuffer = clientRequirementsBuffer = clientEventBuffer;
+
+    messageBusListenerOffset = 0;
+
+    // Set default security requirements
+    microBitEventCharacteristic.requireSecurity(SecurityManager::MICROBIT_BLE_SECURITY_LEVEL);
+    clientEventCharacteristic.requireSecurity(SecurityManager::MICROBIT_BLE_SECURITY_LEVEL);
+    clientRequirementsCharacteristic.requireSecurity(SecurityManager::MICROBIT_BLE_SECURITY_LEVEL);
+    microBitRequirementsCharacteristic->requireSecurity(SecurityManager::MICROBIT_BLE_SECURITY_LEVEL);
+
+    GattCharacteristic *characteristics[] = {&microBitEventCharacteristic, &clientEventCharacteristic, &clientRequirementsCharacteristic, microBitRequirementsCharacteristic};
+    GattService         service(MicroBitEventServiceUUID, characteristics, sizeof(characteristics) / sizeof(GattCharacteristic *));
+
+    ble.addService(service);
+
+    microBitEventCharacteristicHandle = microBitEventCharacteristic.getValueHandle();
+    clientEventCharacteristicHandle = clientEventCharacteristic.getValueHandle();
+    clientRequirementsCharacteristicHandle = clientRequirementsCharacteristic.getValueHandle();
+
+    ble.onDataWritten(this, &MicroBitEventService::onDataWritten);
+
+    fiber_add_idle_component(this);
+}
+
+
+/**
+  * Callback. Invoked when any of our attributes are written via BLE.
+  */
+void MicroBitEventService::onDataWritten(const GattWriteCallbackParams *params)
+{
+    int len = params->len;
+    EventServiceEvent *e = (EventServiceEvent *)params->data;
+
+    if (params->handle == clientEventCharacteristicHandle) {
+
+        // Read and fire all events...
+        while (len >= 4)
+        {
+            MicroBitEvent evt(e->type, e->reason);
+            len-=4;
+            e++;
+        }
+        return;
+    }
+
+    if (params->handle == clientRequirementsCharacteristicHandle) {
+        // Read and register for all the events given...
+        while (len >= 4)
+        {
+            messageBus.listen(e->type, e->reason, this, &MicroBitEventService::onMicroBitEvent, MESSAGE_BUS_LISTENER_IMMEDIATE);
+
+            len-=4;
+            e++;
+        }
+        return;
+    }
+}
+
+/**
+  * Callback. Invoked when any events are sent on the microBit message bus.
+  */
+void MicroBitEventService::onMicroBitEvent(MicroBitEvent evt)
+{
+    EventServiceEvent *e = &microBitEventBuffer;
+
+    if (ble.getGapState().connected) {
+        e->type = evt.source;
+        e->reason = evt.value;
+
+        ble.gattServer().notify(microBitEventCharacteristicHandle, (const uint8_t *)e, sizeof(EventServiceEvent));
+    }
+}
+
+/**
+  * Periodic callback from MicroBit scheduler.
+  * If we're no longer connected, remove any registered Message Bus listeners.
+  */
+void MicroBitEventService::idleTick()
+{
+    if (!ble.getGapState().connected && messageBusListenerOffset >0) {
+        messageBusListenerOffset = 0;
+        messageBus.ignore(MICROBIT_ID_ANY, MICROBIT_EVT_ANY, this, &MicroBitEventService::onMicroBitEvent);
+    }
+}
+
+/**
+  * Read callback on microBitRequirements characteristic.
+  *
+  * Used to iterate through the events that the code on this micro:bit is interested in.
+  */
+void MicroBitEventService::onRequirementsRead(GattReadAuthCallbackParams *params)
+{
+    if (params->handle == microBitRequirementsCharacteristic->getValueHandle())
+    {
+        // Walk through the lsit of message bus listeners.
+        // We send one at a time, and our client can keep reading from this characterisitic until we return an emtpy value.
+        MicroBitListener *l = messageBus.elementAt(messageBusListenerOffset++);
+
+        if (l != NULL)
+        {
+            microBitRequirementsBuffer.type = l->id;
+            microBitRequirementsBuffer.reason = l->value;
+            ble.gattServer().write(microBitRequirementsCharacteristic->getValueHandle(), (uint8_t *)&microBitRequirementsBuffer, sizeof(EventServiceEvent));
+        } else {
+            ble.gattServer().write(microBitRequirementsCharacteristic->getValueHandle(), (uint8_t *)&microBitRequirementsBuffer, 0);
+        }
+    }
+}
+
+const uint8_t  MicroBitEventServiceUUID[] = {
+    0xe9,0x5d,0x93,0xaf,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};
+
+const uint8_t  MicroBitEventServiceMicroBitEventCharacteristicUUID[] = {
+    0xe9,0x5d,0x97,0x75,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};
+
+const uint8_t  MicroBitEventServiceClientEventCharacteristicUUID[] = {
+    0xe9,0x5d,0x54,0x04,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};
+
+const uint8_t  MicroBitEventServiceMicroBitRequirementsCharacteristicUUID[] = {
+    0xe9,0x5d,0xb8,0x4c,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};
+
+const uint8_t  MicroBitEventServiceClientRequirementsCharacteristicUUID[] = {
+    0xe9,0x5d,0x23,0xc4,0x25,0x1d,0x47,0x0a,0xa0,0x62,0xfa,0x19,0x22,0xdf,0xa9,0xa8
+};