uint8_t* pack_bytes(uint8_t* b, uint8_t* e, ...)
pack_bytes takes container class begin(), end() iterators as parameters and writes the data specified by the following parameters into the container as a byte sequence.
The data types given as variadic arguments are as follows.
| Data Type | Bytes | Description |
|---|---|---|
uint8_t | 1 | |
uint16_t | 2 | Stored in big-endian order |
uint32_t | 4 | Stored in big-endian order |
uint8_t[N] | N | Fixed-length array of uint8_t |
std::pair<char*,N> | N | Pair of array and length for char* or uint8_t* arrays. Can be created with make_pair(). |
smplbuf_u8& pack_bytes(smplbuf_u8& c, ...)
pack_bytes takes a container object as a parameter and writes the data specified by the following parameters into the container as a byte sequence. It appends to the end using the container’s .push_back() method.
The data types given as variadic arguments are as follows.
| Data Type | Bytes | Description |
|---|---|---|
uint8_t | 1 | |
uint16_t | 2 | Stored in big-endian order |
uint32_t | 4 | Stored in big-endian order |
uint8_t[N] | N | Fixed-length array of uint8_t |
std::pair<char*,N> | N | Pair of array and length for char* or uint8_t* arrays. Can be created with make_pair(). |
smplbuf_u8? | .size() | smplbuf<> container of uint8_t type. Stores data of container length (.size()). |
Example
auto&& rx = the_twelite.receiver.read();
smplbuf<uint8_t, 128> buf;
mwx::pack_bytes(buf
, uint8_t(rx.get_addr_src_lid()) // src addr (LID)
, uint8_t(0xCC) // cmd id (0xCC, fixed)
, uint8_t(rx.get_psRxDataApp()->u8Seq) // sequence number
, uint32_t(rx.get_addr_src_long()) // src addr (long)
, uint32_t(rx.get_addr_dst()) // dst addr
, uint8_t(rx.get_lqi()) // LQI
, uint16_t(rx.get_length()) // payload length
, rx.get_payload() // payload
);
In this example, attributes and payload of the received packet are re-stored into another buffer buf.
Background
To simplify the description of byte arrays of type uint8_t used for generating data payloads of wireless packets and extracting data.
auto&& rx = the_twelite.receiver.read();
uint8_t data[128];
data[0] = rx.get_addr_src_lid();
data[1] = 0xCC;
data[2] = rx.get_psRxDataApp()->u8Seq;
data[4] = rx.get_addr_src_long() & 0x000000FF;
data[5] = (rx.get_addr_src_long() & 0x0000FF00) >> 8;
data[6] = (rx.get_addr_src_long() & 0x00FF0000) >> 16;
data[7] = (rx.get_addr_src_long() & 0xFF000000) >> 24;
...
The above is the simplest description, but a byte array can be generated using Byte array utils as follows.
auto&& rx = the_twelite.receiver.read();
uint8_t data[128], *q = data;
S_OCTET(q, rx.get_addr_src_lid());
S_OCTET(q, 0xCC);
S_OCTET(q, rx.get_psRxDataApp()->u8Seq);
S_DWORD(q, rx.get_addr_src_long());
S_DWORD(q, rx.get_addr_dst());
S_OCTET(q, rx.get_lqi());
S_WORD(q, rx.get_length());
for (auto x : rx.get_payload()) {
S_OCTET(q, x);
}