Helium for ARM mbed

File content as of revision 7:e6743e01b7cb:

/**
 * Copyright 2017, Helium Systems, Inc.
 * All Rights Reserved. See LICENCE.txt for license information
 */

#ifndef HELIUM_H
#define HELIUM_H

#include "mbed.h"
#include "BufferedSerial.h"
#include "helium-client/helium-client.h"


/**
 * \class Helium
 *
 * \brief Enables communication with the Helium Atom
 *
 * This class offers the basic ability to communicate with the Helium
 * Atom module.
 *
 * \copyright Copyright 2017, Helium Systems, Inc.  All Rights
 * Reserved. See LICENCE.txt for license information
 *
 */
class Helium
{
  public:
    /** Create a Helium instance on a hardware serial port.
     *
     * @param serial The hardware serial port to use
     */
    Helium(PinName tx, PinName rx);

    /** Set communication speed with the Helium Atom.
     *
     * This sets communication speed with the Helium Atom to the given
     * value.
     *
     * @param baud The baud rate to use.
     */
    int baud(enum helium_baud baud);

    /** Get information on the Helium atom
     *
     * Gets basic information about the Helium Atom such as it's MAC
     * address and the current network time, if connected.
     *
     * @param info The information structure to fill out
     */
    int info(struct helium_info * info);

    /** Connect the Helium Atom to the network.
     *
     * This tries to connect the Helium Atom to a nearby Element and
     * the Helium Network. Connections can be quick or slow. A quick
     * connection attempt to re-connect to the network using revious
     * _connection_ state which was retrieved using %sleep. If the
     * quick connect was not requested or if it fails a normal, slower
     * connection attempt is made.
     *
     * Connect is an asynchronous operation. The given are a
     * convenience to attempt a number of retries before returning the
     * current connection state.
     *
     * @param connection A previously retrieved connection structure
     *        that reflects sleep state.
     *
     * @param retries The number of retries to attempt to connect.
     *
     * @return helium_connect_status
     *
     * @see Helium#connect()
     */
    int connect(struct connection * connection, uint32_t retries);

    /** Short form connect to the Helium Network.
     *
     * This is the recommended connect call. It assumes no connection
     * state and tries to connect for up to a 5 seconds.
     *
     */
    int connect()
    {
        return connect(NULL, HELIUM_POLL_RETRIES_5S);
    }

    /** Check if the Atom is connected to the network
     *
     * Checks whether the Atom is connected to the network.
     *
     * @returns true if connected, false if not connected
     */
    bool connected();

    /** Disconnects the Atom from the network and puts it in sleep mode.
     *
     * This disconnects the Helium Atom from the network and puts it
     * in sleep mode. If a connection structure is given, it is filled
     * with sleep state which can be used in a sub-sequent connect
     * call to quick connect to the network.
     *
     * @param connection Sleep connection buffer to fill in.
     *
     * @see Helium::sleep() for the easy version.
     */
    int sleep(struct connection * connection);

    /** Disconnect the Atom and put it to sleep.
     *
     * This is the convenience version of sleep. A subsequent connect
     * call will go through a normal connect cycle.
     *
     */
    int  sleep()
    {
        return sleep(NULL);
    }

  public:
    BufferedSerial<16> serial;
    struct helium_ctx _ctx;

    friend class Channel;
};

/**
 * \class Channel
 *
 * \brief A Channel to an IoT platform.
 *
 * Channels represent a delivery mechanism from the device to a number
 * of supported back-end IoT platforms.
 *
 * To use a channel, make sure you have it set up in your Helium
 * Dashboard and then call Channel#begin with the channel name as you
 * configured it on the Helium Dashboard. This will automatically
 * ensure that the device is securely authenticated and registered
 * with the channel.
 *
 */
class Channel
{
  public:
    /** Construct a channel.
     *
     * @param helium The Helium Atom to communicate with
     */
    Channel(Helium * helium);

    /** Begin communicating over a channel
     *
     * Always call this method before calling Channel#send. Beginning
     * communication will ensure that the device is authenticated and
     * registered with the channel with the given name as configured
     * in the Helium Dashboard.
     *
     * The `result` value will be 0 if the channel was created
     * successfully and non-`0` otherwise.
     *
     * @param name The name of the channel to authenticate with.
     * @param result An out parameter for the result of the request.
     */
    int begin(const char * name, int8_t * result);

    /** Send data to this channel.
     *
     * Send data to a given channel. The given data is sent to the
     * configured channel and the result as returned by the channel is
     * put in the `result` output variable. The result value is `0`
     * for success and non-`0` if an error occurred.
     *
     * @note The maximum number of bytes that can be transmitted is
     * limited to HELIUM_MAX_DATA_SIZE (about 100 bytes).
     *
     * @param data The data bytes to send
     * @param len The number of bytes in data to send
     * @param result An out parameter for the result returned by the channel
     */
    int send(void const * data, size_t len, int8_t * result);

    /** Asynchronous begin method.
     *
     * The Channel#begin(const char *) method is a synchronous version
     * of this method. Sending a request to a channel returns a
     * `token` which can be used in a subsequent call to #poll() to
     * check for results from the remote channel.
     *
     * @param name The name of the channel to authenticate with.
     * @param token The output parameter for the pending result token.
     */
    int begin(const char * name, uint16_t * token);

    /** Asynchornous send method.
     *
     * This is the asynchronous version of the #send(void const *data,
     * size_t int8_t *) method.
     *
     * @param data The data bytes to send
     * @param len The number of bytes in data to send
     * @param token The output parameter for the pending result token
     */
    int send(void const * data, size_t len, uint16_t * token);

    /** Poll for a result token.
     *
     * This polls the Helium Atom for the given number of retries for
     * the result of a given `token`. Use HELIUM_POLL_RETRIES_5S for
     * the recommended number of retries.
     *
     * If succcessful the result will be helium_status_OK and the
     * result value will be set to the result of the original request
     * that the token represents.
     *
     * @param token The token to check for
     * @param result The out parameter for the result of the given request token
     * @param retries The number of times to retry
     */
    int poll(uint16_t token, int8_t * result, uint32_t retries);

  private:
    Helium * _helium;
    int8_t   _channel_id;
};

#endif // HELIUM_H