2. Device features
2.1. MultiPath APRS packets decoding
In PLXDigi device we resigned from hardware packet decoding method. MultiPath
APRS packet decoding algorithm is a digital signal processing based method utilizing
features of modern 32-bit microcontrollers used in our devices.
MultiPath decoding allows to decode received packets simultaneously by two
decoding algorithms, with different digital filters applied to both paths. Packets
distorted by low-frequency components or with imbalanced 1200/2200Hz tones are
prefiltered which increases the probability of correct packet decoding.
2.2. APRS client
PLXDigi allows you to generate APRS data packets with information field defined
by user and send them in a specified interval. In this way, it is possible to send beacons,
objects, weather and telemetry data.
2.3. APRS digipeater
The main purpose of the device is receiving and sending APRS data packets via
amateur radio transceiver. PLXDigi is capable of receiving an APRS packet, decoding the
sender, recipent, path and information field. Then actions are performed in accordance
with the options configured by user:
•
Packet is digipeated via the APRS network,
•
Packet is ignored if it was corrupted.
Device firmware implements the following mechanisms:
•
Checksum Verification - packets with errors are ignored,
•
Anti-flood - packets repeated in a short time interval are not forwarded,
•
Path checking - a decision whether to digipeat a packet or not is made using a
filter stored in configuration data of the device. User defines whether to forward
WIDE1-1, WIDEn-N, SPn-N, or local path packets and the maximum value of N (so
called New-N paradigm),
•
Callsign filter - a simple callsign filter allows you to add stations to black list
(these stations will be ignored) or white list (only these stations will be
digipeated).
2.4. Weather station support
PLXDigi allows you to receive weather data from compatible weather stations
over RS-232 serial interface. Currently supported stations are:
•
LaCrosse/Technoline WS-2300,
•
LaCrosse/Technoline WS-2350,
•
Peet Bros Ultimeter 100,
•
Peet Bros Ultimeter 800,
•
Peet Bros Ultimeter 2000,
•
Peet Bros Ultimeter 2100,
•
Davis Vantage Pro (with RS-232 datalogger),
•
Davis Vantage Pro2 (with RS-232 datalogger),
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