HRFReliableDatagram Class Reference

Class for sending addressed, acknowledged, retransmitted datagrams. More...

#include <HRFReliableDatagram.h>

Inheritance diagram for HRFReliableDatagram:

Public Member Functions
	HRFReliableDatagram (HardwareSerial *serial=&Serial, uint8_t thisAddress=0)
virtual void	setTimeout (long timeout)
virtual void	setRetries (uint8_t retries)
virtual uint8_t	sendtoWait (uint8_t address, uint8_t *buf, uint8_t len)
virtual uint8_t	recvfromAck (uint8_t *buf, uint8_t *len, uint8_t *from=NULL, uint8_t *to=NULL)
Public Member Functions inherited from HRFDatagram
	HRFDatagram (HardwareSerial *serial=&Serial, uint8_t thisAddress=0)
virtual void	setThisAddress (uint8_t thisAddress)
virtual uint8_t	sendto (uint8_t address, uint8_t *buf, uint8_t len)
virtual uint8_t	recvfrom (uint8_t *buf, uint8_t *len, uint8_t *from=NULL, uint8_t *to=NULL, uint8_t promiscuous=0)
virtual uint8_t	recv (uint8_t *buf, uint8_t *len)
Public Member Functions inherited from HRFMessage
	HRFMessage (HardwareSerial *serial=&Serial)
virtual uint8_t	send (uint8_t *buf, uint8_t len)
virtual uint8_t	available ()
virtual uint8_t	rx_bad (void)
virtual uint8_t	rx_good (void)
virtual void	waitAvailable (void)

Additional Inherited Members
Protected Attributes inherited from HRFDatagram
uint8_t	_thisAddress
	The address of this node. Defaults to 0.

Detailed Description

Class for sending addressed, acknowledged, retransmitted datagrams.

Extends HRFDatagram to define addressed, reliable datagrams with acknowledgement and retransmission. Based on HRFDatagram, adds flags and sequence numbers. HRFReliableDatagram is reliable in the sense that messages are acknowledged, and unacknowledged messages are retransmitted until acknowledged or the retries are exhausted. When addressed messages are collected by the application (recvfromAck), an acknowledgement is automatically sent. When addressed messages are sent (by sendtoWait), it will wait for an ack, and retransmit after timeout until an ack is received or retries are exhausted ReliableDatagrams have format LEN DEST SRC FLAG/SQN payload FCS-LO FCS-HI Low 7 bits of FLAG/SQN is the sequence number. Most significant bit is the ACK flag.

Part of the Arduino HopeRF library for operating with HopeRF HM-TR transceivers (see http://www.hoperf.com)

Constructor & Destructor Documentation

HRFReliableDatagram::HRFReliableDatagram	(	HardwareSerial *	serial = &Serial,
		uint8_t	thisAddress = 0
	)

Parameters

[in]	serial	The instance of HardwareSerial to use for IO. Defaults to &Serial,
[in]	thisAddress	The address to assign to this node. Defaults to 0

Member Function Documentation

uint8_t HRFReliableDatagram::recvfromAck ( uint8_t *  buf, uint8_t *  len, uint8_t *  from = NULL, uint8_t *  to = NULL  )

virtual

If there is a valid message available for this node, send an acknowledgement to the SRC address (blocking until this is complete), then copy the message to buf and return true else return false. If a message is copied, *len is set to the length.. If from is not NULL, the SRC address is placed in *from. If to is not NULL, the DEST address is placed in *to. This is the preferred function for getting messages addressed to this node. If the message is not a broadcast, acknowledge to the sender before returning.

Parameters

[in]	buf	Location to copy the received message
[in]	len	Available space in buf. Set to the actual number of octets copied.
[in]	from	If present and not NULL, the referenced uint8_t will be set to the SRC address
[in]	to	If present and not NULL, the referenced uint8_t will be set to the DEST address

References HRFDatagram::recvfrom(), and HRFDatagram::sendto().

uint8_t HRFReliableDatagram::sendtoWait ( uint8_t  address, uint8_t *  buf, uint8_t  len  )

virtual

Send the message and waits for an ack. Returns true if an acknowledgement is received. Synchronous: any message other than the desired ACK received while waiting is discarded. Blocks until an ACK is received or all retries are exhausted (ie up to retries*timeout milliseconds).

Parameters

[in]	address	The address to send the message to.
[in]	buf	Pointer to the binary message to send
[in]	len	Number of octets to send

Returns

true if the message was transmitted and an acknowledgement is received.

false if the message is too long (>HRF_MAX_DATAGRAM_PAYLOAD).

References HRFDatagram::_thisAddress, HRFDatagram::recvfrom(), and HRFDatagram::sendto().

void HRFReliableDatagram::setRetries ( uint8_t  retries )

virtual

Sets the max number of retries. Defaults to 3. If set to 0, the message will only be sent once. sendtoWait will give up if there is no ack received after all transmissions time out. param[in] retries The maximum number a retries.

void HRFReliableDatagram::setTimeout ( long  timeout )

virtual

Sets the retransmit timeout. If sendtoWait is waiting for an ack longer than this time (in milliseconds), it will retransmit the message. Defaults to 1000ms. The timeout is measured from the beginning of transmission of the message. It must be longer than the transmit time of the request plus the transmit time of the acknowledgement (6 octets) plus the latency of the receiver.

Parameters

[in]

timeout

The new timeout period in milliseconds

---

The documentation for this class was generated from the following files:

• HRFReliableDatagram.h
• HRFReliableDatagram.cpp