Module channel

Expand description

Pointing a concentrator at the channels it listens on.

A concentrator that has been reset, identified and given firmware still hears nothing. Its receivers have not been told which intermediate frequencies to listen on, which radio each takes its samples from, which spreading factors to look for, or that they may run at all. This is what closes that gap.

There are ten receivers. Eight take any spreading factor and share a bandwidth fixed in hardware at 125 kHz. One more is fixed to a single spreading factor and bandwidth, which is what a network calls its service channel. The last hears frequency shift keying.

Every frequency here is an offset from the carrier a front end is tuned to, not a carrier of its own, which is why a plan is described relative to the radio it sits on.

Nothing here opens a bus. The order is data, so it can be checked against the reference with no hardware present.

Structs§

Fsk: The receiver that hears frequency shift keying rather than LoRa.
Implicit: What a receiver is told when the packets it hears carry no header of their own.
Listener: One of the receivers that takes any spreading factor.
Plan: What a concentrator is to listen for.
Service: The receiver fixed to one spreading factor, which is what a network calls its service channel.

Enums§

Step: A step in pointing a concentrator at its channels.

Constants§

DFT_PEAK_AUTOMATIC: Peak selection left to the receiver.
FSK_BANDWIDTH_CODE: How wide the FSK receiver listens, which is the setting for a 125 kHz channel.
FSK_CLOCK_HZ: The clock the FSK bit rate is counted against, in hertz.
FSK_DEFAULT_BITRATE: The bit rate a LoRaWAN network runs its frequency shift keying channel at.
FSK_MAX_PAYLOAD: The longest packet the FSK receiver takes.
FSK_RSSI_SAMPLES: How many samples the FSK receiver measures a signal level over.
FSK_SYNC_WORD: The sync word that channel looks for.
FSK_SYNC_WORD_LEN: How many bytes of it there are.
FSK_TIMEOUT: How long it waits for one, as the receiver counts it.
FSK_TOLERANCE: How far the bit timing may drift before a packet is given up on.
FSK_WHITENING: Keeping the bits from settling at one level, which a LoRaWAN FSK channel whitens.
MAX_OFFSET_HZ: How far from the carrier a channel can sit, in hertz.
MAX_SPREADING_FACTOR: The highest.
MIN_SPREADING_FACTOR: The lowest spreading factor a receiver can be asked for.
MULTI_BANDWIDTH_HZ: The bandwidth every multi-spreading-factor receiver runs at, in hertz.
MULTI_CHANNELS: How many receivers take any spreading factor.
PREAMBLE_SYMBOLS: How many preamble symbols a receiver waits for.
RSSI_DEFAULT: What the channel power reading starts from.
RSSI_FILTER_ALPHA: How heavily that reading is filtered.
RX_BANDWIDTH_HZ: How much spectrum one radio hears in total, in hertz.
SERVICE_PEAK_COUNT: How many peaks the fixed-rate receiver counts before it believes a preamble.
SERVICE_PEAK_TO_NOISE: How far above the noise a peak has to be for the fixed-rate receiver to take it.
SERVICE_PREAMBLE_SYMBOLS: How many preamble symbols the fixed-rate receiver expects at the usual spreading factors.
SERVICE_PREAMBLE_SYMBOLS_FAST: How many it expects at the two fastest, which is what end device drivers send there.
SERVICE_SECOND_PEAK_COUNT: How many peaks it counts on the second pass.
TIMING_LINEAR: Fine timing that follows the drift in a straight line.
TRACKING_AUTOMATIC: Frequency tracking left to the receiver.
TRACKING_OFF: Frequency tracking switched off.

Functions§

drift: How fast a frequency error turns into a timing one, as a mantissa and a shift.
every_spreading_factor: Every spreading factor, as the mask the chip takes.
low_rate_optimize: Whether a rate is slow enough to need the low data rate optimization.
offset_bytes: Splits a channel offset into the two bytes its registers take.
offset_value: Turns an offset from the carrier into the value a channel register takes.
reachable: Whether a channel offset is one the radio can actually hear.
steps: The order a concentrator is pointed at its channels in.

Module channel

Module channel Copy item path

Structs§

Enums§

Constants§

Functions§

Module channel