LibrePilot/flight/OpenPilot/Modules/Telemetry/telemetry.c

/**
 ******************************************************************************
 *
 * @file       telemetry.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      Telemetry module, handles telemetry and UAVObject updates
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <stdlib.h> // for malloc
#include "telemetry.h"
#include "uavtalk.h"
#include "uavobjectmanager.h"
#include "eventdispatcher.h"
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "semphr.h"

// Private constants
#define MAX_QUEUE_SIZE 20
#define STACK_SIZE 100
#define TASK_PRIORITY 100
#define REQ_TIMEOUT_MS 500
#define MAX_RETRIES 2

// Private types

// Private variables
xQueueHandle queue;
xTaskHandle telemetryTaskHandle;

// Private functions
void telemetryTask();
void receiveTask();
void periodicEventHandler(UAVObjEvent* ev);
int32_t transmitData(uint8_t* data, int32_t length);
void registerObject(UAVObjHandle obj);
void updateObject(UAVObjHandle obj);
int32_t addObject(UAVObjHandle obj);
int32_t setUpdatePeriod(UAVObjHandle obj, int32_t updatePeriodMs);

/**
* Initialize the telemetry module
* \return -1 if initialization failed
* \return 0 on success
*/
int32_t TelemetryInitialize()
{
	// Create object queue
	queue = xQueueCreate(MAX_QUEUE_SIZE, sizeof(UAVObjEvent));

	// TODO: Get telemetry settings object

	// TODO: Initialize communication ports

	// Initialize UAVTalk
	UAVTalkInitialize(&transmitData);

	// Process all registered objects and connect queue for updates
	UAVObjIterate(&registerObject);

	// Start telemetry task
	xTaskCreate( telemetryTask, (signed char*)"Telemetry", STACK_SIZE, NULL, TASK_PRIORITY, &telemetryTaskHandle );

	return 0;
}

/**
* Register a new object, adds object to local list and connects the queue depending on the object's
* telemetry settings.
* \param[in] obj Object to connect
*/
void registerObject(UAVObjHandle obj)
{
	// Setup object for periodic updates
	addObject(obj);

	// Setup object for telemetry updates
	updateObject(obj);
}

/**
 * Update object's queue connections and timer, depending on object's settings
 * \param[in] obj Object to updates
 */
void updateObject(UAVObjHandle obj)
{
	UAVObjMetadata metadata;
	int32_t eventMask;

	// Get metadata
	UAVObjGetMetadata(obj, &metadata);

	// Setup object depending on update mode
	if (metadata.telemetryUpdateMode == UPDATEMODE_PERIODIC)
	{
		// Set update period
		setUpdatePeriod(obj, metadata.telemetryUpdatePeriod);
		// Connect queue
		eventMask = EV_UPDATED_MANUAL|EV_UPDATE_REQ;
		if (UAVObjIsMetaobject(obj))
		{
			eventMask |= EV_UNPACKED; // we also need to act on remote updates (unpack events)
		}
		UAVObjConnectQueue(obj, queue, eventMask);
	}
	else if (metadata.telemetryUpdateMode == UPDATEMODE_ONCHANGE)
	{
		// Set update period
		setUpdatePeriod(obj, 0);
		// Connect queue
		eventMask = EV_UPDATED|EV_UPDATED_MANUAL|EV_UPDATE_REQ;
		if (UAVObjIsMetaobject(obj))
		{
			eventMask |= EV_UNPACKED; // we also need to act on remote updates (unpack events)
		}
		UAVObjConnectQueue(obj, queue, eventMask);
	}
	else if (metadata.telemetryUpdateMode == UPDATEMODE_MANUAL)
	{
		// Set update period
		setUpdatePeriod(obj, 0);
		// Connect queue
		eventMask = EV_UPDATED_MANUAL|EV_UPDATE_REQ;
		if (UAVObjIsMetaobject(obj))
		{
			eventMask |= EV_UNPACKED; // we also need to act on remote updates (unpack events)
		}
		UAVObjConnectQueue(obj, queue, eventMask);
	}
	else if (metadata.telemetryUpdateMode == UPDATEMODE_NEVER)
	{
		// Set update period
		setUpdatePeriod(obj, 0);
		// Disconnect queue
		UAVObjDisconnectQueue(obj, queue);
	}
}

/**
 * Telemetry task. Processes queue events and periodic updates. It does not return.
 */
void telemetryTask()
{
	UAVObjEvent ev;
	UAVObjMetadata metadata;
	int32_t retries;
	int32_t success;


	// Loop forever
	while (1)
	{
		// Wait for queue message
		if ( xQueueReceive(queue, &ev, portMAX_DELAY) == pdTRUE )
		{
			// Get object metadata
			UAVObjGetMetadata(ev.obj, &metadata);
			// Act on event
			if (ev.event == EV_UPDATED || ev.event == EV_UPDATED_MANUAL)
			{
				// Send update to GCS (with retries)
				retries = 0;
				while (retries < MAX_RETRIES && success == -1)
				{
					success = UAVTalkSendObject(ev.obj, ev.instId, metadata.ackRequired, REQ_TIMEOUT_MS); // call blocks until ack is received or timeout
					++retries;
				}
			}
			else if (ev.event == EV_UPDATE_REQ)
			{
				// Request object update from GCS (with retries)
				retries = 0;
				while (retries < MAX_RETRIES && success == -1)
				{
					success = UAVTalkSendObjectRequest(ev.obj, ev.instId, REQ_TIMEOUT_MS); // call blocks until update is received or timeout
					++retries;
				}
			}
			// If this is a metadata object then make necessary telemetry updates
			if (UAVObjIsMetaobject(ev.obj))
			{
				updateObject(UAVObjGetLinkedObj(ev.obj)); // linked object will be the actual object the metadata are for
			}
		}

		// TODO: Check for received data (from the modem or USB) and pass them to UAVTalk for decoding
		// UAVTalkProcessInputStream(data);
	}
}

/**
 * Transmit data buffer to the modem or USB port.
 * \param[in] data Data buffer to send
 * \param[in] length Length of buffer
 */
int32_t transmitData(uint8_t* data, int32_t length)
{
	// TODO: Send data to communication port
	return 0;
}

/**
 * Event handler for periodic object updates (called by the event dispatcher)
 */
void periodicEventHandler(UAVObjEvent* ev)
{
	// Push event to the telemetry queue
	xQueueSend(queue, ev, 0); // do not wait if queue is full
}

/**
 * Setup object for periodic updates.
 * \param[in] obj The object to update
 * \return 0 Success
 * \return -1 Failure
 */
int32_t addObject(UAVObjHandle obj)
{
	UAVObjEvent ev;

	// Add object for periodic updates
	ev.obj = obj;
	ev.instId = UAVOBJ_ALL_INSTANCES;
	ev.event = EV_UPDATED_MANUAL;
	return EventPeriodicCreate(&ev, &periodicEventHandler, 0);
}

/**
 * Set update period of object (it must be already setup for periodic updates)
 * \param[in] obj The object to update
 * \param[in] updatePeriodMs The update period in ms, if zero then periodic updates are disabled
 * \return 0 Success
 * \return -1 Failure
 */
int32_t setUpdatePeriod(UAVObjHandle obj, int32_t updatePeriodMs)
{
	UAVObjEvent ev;

	// Add object for periodic updates
	ev.obj = obj;
	ev.instId = UAVOBJ_ALL_INSTANCES;
	ev.event = EV_UPDATED_MANUAL;
	return EventPeriodicUpdate(&ev, &periodicEventHandler, updatePeriodMs);
}