Module spi 

The SPI transactions the SX1302 answers.

Every transfer starts with a target byte, because the concentrator sits in front of the radios and passes a transfer through to whichever the first byte names. After that comes a command byte carrying the access bit and the top seven bits of the address, then the low eight bits, then the data.

A read costs two bytes more than a write: the chip needs a byte to turn the bus around, so the host clocks out a dummy and reads the answer in the last byte it receives.

These functions build the bytes and read them back. They touch no bus, so a caller can check a frame against the datasheet, or replay one captured from a working gateway, without any hardware present.

Constants

BURST_CHUNK

The most bytes one burst carries before the host starts another.

BURST_READ_HEADER_LEN

How many bytes the header of a burst read takes, before the data.

BURST_WRITE_HEADER_LEN

How many bytes the header of a burst write takes, before the data.

CLOCK_HZ

The clock the concentrator is driven at, in hertz.

READ_ACCESS

The access bit for a read, which is the absence of the write bit.

READ_LEN

How many bytes a single-byte read transfer takes.

TARGET_CONCENTRATOR

The concentrator itself, rather than a radio behind it.

TARGET_RADIO_A

The radio on the first chain, reached through the concentrator.

TARGET_RADIO_B

The radio on the second chain.

WRITE_ACCESS

The access bit for a write, the top bit of the command byte.

WRITE_LEN

How many bytes a single-byte write transfer takes.

Functions

burst_read_header

Builds the header that precedes the data of a burst read.

burst_write_header

Builds the header that precedes the data of a burst write.

chunks

Walks a long transfer as the chunks it actually goes out in.

field

Reads the bits a register holds out of the byte it lives in.

read

Builds the transfer that reads one byte from a register.

read_value

Takes the byte a read transfer brought back.

with_field

Puts a value into the bits a register holds, leaving the rest of the byte alone.

write

Builds the transfer that writes one byte to a register.