Helium / helium

An mbed wrapper around the helium-client to communicate with the Helium Atom

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Channel Class Reference
Public Member Functions | Data Fields | Friends

Channel Class Reference

A Channel to an IoT platform. More...

#include <Helium.h>

Public Member Functions

 Channel (Helium *helium)
 Construct a channel.
int begin (const char *name, int8_t *result)
 Begin communicating over a channel.
int send (void const *data, size_t len, int8_t *result)
 Send data to this channel.
int begin (const char *name, uint16_t *token)
 Asynchronous begin method.
int send (void const *data, size_t len, uint16_t *token)
 Asynchornous send method.
int poll_result (uint16_t token, int8_t *result, uint32_t retries=HELIUM_POLL_RETRIES_5S)
 Poll for a result token.
int poll_data (void *data, size_t len, size_t *used, uint32_t retries=HELIUM_POLL_RETRIES_5S)
 Poll for data on a channel.

Data Fields

Helium * helium
 The Helium Atom this channel uses to communicate.

Friends

class Config

Detailed Description

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.

Definition at line 131 of file Helium.h.

Constructor & Destructor Documentation

Channel ( Helium *  helium )

Construct a channel.

Parameters:
heliumThe Helium Atom to communicate with

Definition at line 113 of file Helium.cpp.

Member Function Documentation

int begin ( const char *  name,
int8_t *  result 
)

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.

Parameters:
nameThe name of the channel to authenticate with.
resultAn out parameter for the result of the request.

Definition at line 125 of file Helium.cpp.

int begin ( const char *  name,
uint16_t *  token 
)

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.

Parameters:
nameThe name of the channel to authenticate with.
tokenThe output parameter for the pending result token.

Definition at line 119 of file Helium.cpp.

int poll_data ( void *  data,
size_t  len,
size_t *  used,
uint32_t  retries = HELIUM_POLL_RETRIES_5S 
)

Poll for data on a channel.

This polls the Helium Atom for the given number of retries for any data on the channel.

If successful the result will be helium_status_OK and the given `data` buffer will be filled with the received data. The `used` out parameter will be set to the number of bytes read. Note that the maximum number of bytes that can be sent is set by HELIUM_MAX_DATA_SIZE.

Parameters:
[out]dataThe data buffer to fill with received data
lenThe available length of the data buffer
[out]usedOn success the number of bytes used up in data
retriesThe number of times to retry

Definition at line 169 of file Helium.cpp.

int poll_result ( uint16_t  token,
int8_t *  result,
uint32_t  retries = HELIUM_POLL_RETRIES_5S 
)

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.

Parameters:
tokenThe token to check for
result[out]The result of the given request token
retriesThe number of times to retry

Definition at line 163 of file Helium.cpp.

int send ( void const *  data,
size_t  len,
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).
Parameters:
dataThe data bytes to send
lenThe number of bytes in data to send
resultAn out parameter for the result returned by the channel

Definition at line 151 of file Helium.cpp.

int send ( void const *  data,
size_t  len,
uint16_t *  token 
)

Asynchornous send method.

This is the asynchronous version of the send(void const *data, size_t int8_t *) method.

Parameters:
dataThe data bytes to send
lenThe number of bytes in data to send
tokenThe output parameter for the pending result token

Definition at line 144 of file Helium.cpp.

Field Documentation

Helium* helium

The Helium Atom this channel uses to communicate.

Definition at line 234 of file Helium.h.

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