-
Notifications
You must be signed in to change notification settings - Fork 1
/
RHDatagram.h
162 lines (137 loc) · 7.41 KB
/
RHDatagram.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
// RHDatagram.h
// Author: Mike McCauley (mikem@airspayce.com)
// Copyright (C) 2011 Mike McCauley
// $Id: RHDatagram.h,v 1.14 2015/08/12 23:18:51 mikem Exp $
#ifndef RHDatagram_h
#define RHDatagram_h
#include <RHGenericDriver.h>
// This is the maximum possible message size for radios supported by RadioHead.
// Not all radios support this length, and many are much smaller
#define RH_MAX_MESSAGE_LEN 255
/////////////////////////////////////////////////////////////////////
/// \class RHDatagram RHDatagram.h <RHDatagram.h>
/// \brief Manager class for addressed, unreliable messages
///
/// Every RHDatagram node has an 8 bit address (defaults to 0).
/// Addresses (DEST and SRC) are 8 bit integers with an address of RH_BROADCAST_ADDRESS (0xff)
/// reserved for broadcast.
///
/// \par Media Access Strategy
///
/// RHDatagram and the underlying drivers always transmit as soon as sendto() is called.
///
/// \par Message Lengths
///
/// Not all Radio drivers supported by RadioHead can handle the same message lengths. Some radios can handle
/// up to 255 octets, and some as few as 28. If you attempt to send a message that is too long for
/// the underlying driver, sendTo() will return false and will not transmit the message.
/// It is the programmers responsibility to make
/// sure that messages passed to sendto() do not exceed the capability of the radio. You can use the
/// *_MAX_MESSAGE_LENGTH definitions or driver->maxMessageLength() to help.
///
/// \par Headers
///
/// Each message sent and received by a RadioHead driver includes 4 headers:<br>
/// \b TO The node address that the message is being sent to (broadcast RH_BROADCAST_ADDRESS (255) is permitted)<br>
/// \b FROM The node address of the sending node<br>
/// \b ID A message ID, distinct (over short time scales) for each message sent by a particilar node<br>
/// \b FLAGS A bitmask of flags. The most significant 4 bits are reserved for use by RadioHead. The least
/// significant 4 bits are reserved for applications.<br>
///
class RHDatagram
{
public:
/// Constructor.
/// \param[in] driver The RadioHead driver to use to transport messages.
/// \param[in] thisAddress The address to assign to this node. Defaults to 0
RHDatagram(RHGenericDriver& driver, uint8_t thisAddress = 0);
/// Initialise this instance and the
/// driver connected to it.
bool init();
/// Sets the address of this node. Defaults to 0.
/// This will be used to set the FROM address of all messages sent by this node.
/// In a conventional multinode system, all nodes will have a unique address
/// (which you could store in EEPROM).
/// \param[in] thisAddress The address of this node
void setThisAddress(uint8_t thisAddress);
/// Sends a message to the node(s) with the given address
/// RH_BROADCAST_ADDRESS is a valid address which will cause the message
/// to be accepted by all RHDatagram nodes within range.
/// \param[in] buf Pointer to the binary message to send
/// \param[in] len Number of octets to send (> 0)
/// \param[in] address The address to send the message to.
/// \return true if the message not too loing fot eh driver, and the message was transmitted.
bool sendto(uint8_t* buf, uint8_t len, uint8_t address);
/// Turns the receiver on if it not already on.
/// If there is a valid message available for this node, copy it to buf and return true
/// The SRC address is placed in *from if present and not NULL.
/// The DEST address is placed in *to if present and not NULL.
/// If a message is copied, *len is set to the length.
/// You should be sure to call this function frequently enough to not miss any messages
/// It is recommended that you call it in your main loop.
/// \param[in] buf Location to copy the received message
/// \param[in,out] len Pointer to available space in buf. Set to the actual number of octets copied.
/// \param[in] from If present and not NULL, the referenced uint8_t will be set to the FROM address
/// \param[in] to If present and not NULL, the referenced uint8_t will be set to the TO address
/// \param[in] id If present and not NULL, the referenced uint8_t will be set to the ID
/// \param[in] flags If present and not NULL, the referenced uint8_t will be set to the FLAGS
/// (not just those addressed to this node).
/// \return true if a valid message was copied to buf
bool recvfrom(uint8_t* buf, uint8_t* len, uint8_t* from = NULL, uint8_t* to = NULL, uint8_t* id = NULL, uint8_t* flags = NULL);
/// Tests whether a new message is available
/// from the Driver.
/// On most drivers, this will also put the Driver into RHModeRx mode until
/// a message is actually received bythe transport, when it will be returned to RHModeIdle.
/// This can be called multiple times in a timeout loop.
/// \return true if a new, complete, error-free uncollected message is available to be retreived by recv()
bool available();
/// Starts the Driver receiver and blocks until a valid received
/// message is available.
void waitAvailable();
/// Blocks until the transmitter
/// is no longer transmitting.
bool waitPacketSent();
/// Blocks until the transmitter is no longer transmitting.
/// or until the timeout occuers, whichever happens first
/// \param[in] timeout Maximum time to wait in milliseconds.
/// \return true if the radio completed transmission within the timeout period. False if it timed out.
bool waitPacketSent(uint16_t timeout);
/// Starts the Driver receiver and blocks until a received message is available or a timeout
/// \param[in] timeout Maximum time to wait in milliseconds.
/// \return true if a message is available
bool waitAvailableTimeout(uint16_t timeout);
/// Sets the TO header to be sent in all subsequent messages
/// \param[in] to The new TO header value
void setHeaderTo(uint8_t to);
/// Sets the FROM header to be sent in all subsequent messages
/// \param[in] from The new FROM header value
void setHeaderFrom(uint8_t from);
/// Sets the ID header to be sent in all subsequent messages
/// \param[in] id The new ID header value
void setHeaderId(uint8_t id);
/// Sets and clears bits in the FLAGS header to be sent in all subsequent messages
/// \param[in] set bitmask of bits to be set
/// \param[in] clear bitmask of flags to clear
void setHeaderFlags(uint8_t set, uint8_t clear = RH_FLAGS_NONE);
/// Returns the TO header of the last received message
/// \return The TO header of the most recently received message.
uint8_t headerTo();
/// Returns the FROM header of the last received message
/// \return The FROM header of the most recently received message.
uint8_t headerFrom();
/// Returns the ID header of the last received message
/// \return The ID header of the most recently received message.
uint8_t headerId();
/// Returns the FLAGS header of the last received message
/// \return The FLAGS header of the most recently received message.
uint8_t headerFlags();
/// Returns the address of this node.
/// \return The address of this node
uint8_t thisAddress();
protected:
/// The Driver we are to use
RHGenericDriver& _driver;
/// The address of this node
uint8_t _thisAddress;
};
#endif