Module sx1250 

The SX1250 front ends a concentrator listens through.

A concentrator has no radio of its own. An SX1250 sits on each chain, and that is what a carrier is tuned to: the concentrator only ever sees an intermediate frequency. Both front ends are reached through the concentrator, on the same SPI device, with the first byte of every frame naming the front end rather than the concentrator.

A front end gives the host no BUSY line to watch, so the wait before a frame is a flat millisecond rather than a pin. The reference does the same.

Nothing here opens a bus. The framing, the register value a carrier becomes, the bands image calibration is run over, and the order a front end is brought up in are all data, so each one can be checked against the reference with no hardware present.

Enums

Standby

Which clock a standby runs on.

Step

A step in bringing a front end up.

Constants

CALIBRATE_ALL

The mask that runs every calibration the chip has.

HEADER_LEN

How many bytes of framing come before a command payload.

IMAGE_CALIBRATE_US

How long image calibration is given to finish, in microseconds.

MODE_STANDBY_RC

The mode a front end reports once it is in standby on its own oscillator.

MODE_STANDBY_XOSC

The mode it reports once it is in standby on the crystal.

OP_CALIBRATE

Runs the calibrations named by a mask.

OP_CALIBRATE_IMAGE

Runs image calibration over a band.

OP_GET_DEVICE_ERRORS

Reads what the chip believes went wrong.

OP_GET_STATUS

Reads the chip status, which carries the mode it is in.

OP_SET_RF_FREQUENCY

Sets the carrier.

OP_SET_RX

Puts the front end in receive.

OP_SET_STANDBY

Selects a standby mode.

OP_WRITE_REGISTER

Writes one of the registers behind the command set.

RX_CONTINUOUS

The timeout that means receive forever.

SETTLE_US

How long a mode change is given to settle, in microseconds.

WAIT_BUSY_US

How long to wait before a frame, in microseconds.

XTAL_HZ

The crystal the front end counts its carrier in, in hertz.

Functions

frequency_bytes

Splits a carrier into the four bytes the frequency command takes.

frequency_value

Turns a carrier into the value the frequency command takes.

header

The two bytes every frame to a front end starts with.

image_band

The pair of bytes image calibration takes for the band a carrier is in.

image_failed

Whether the device errors say image calibration failed.

mode

The mode a status byte reports.

setup

The order a front end is brought up in.

target

Which front end a chain talks to.