Using ARDOP on Teensy TNC (aka TNC-Pi9K6) with LinBPQ on a Raspberry Pi.

1. Introduction.

ARDOP is an open source software TNC, originally written in VB .NET by the Winlink development team to run on Windows. I have ported the code to 'C' and produced versions to run on Linux or a Teensy 3.6 microcontroller. I designed a TNC board (Teensy TNC) with the same size as a Raspberry Pi using the Teensy 3.6 which you can build yourself, or Coastal Chipworks sell a similar device the TNC-Pi9K6 based on my design. As the name suggests this was produced as a 9600 baud packet TNC, but it can be reprogrammed with ARDOP software.

2. Configuration.

This is a minimal configuration for ARDOP, using the Serial port on the Pi Header. There are other options, such as using an i2c interface, using the USB port to use the TNC with hardware other than the Raspberry Pi and adding a Rig control port for frequency control or scanning. See the full ARDOP configuration guide for details.

;

PORT
 ID=ARDOP Serial
 DRIVER=ARDOP
 CONFIG
  SERIAL /dev/serial0 115200
  LOGDIR /dev/shm
  DATETIME
  DEBUGLOG TRUE
  CMDTRACE True
  CWID FALSE
  BUSYWAIT 20
  GRIDSQUARE IO68VL
  MAXCONREQ 5
  ARQBW 2000
  RXLEVEL 0
  TXLEVEL 100
ENDPORT

3. Operation.

As the TNC only supports a single connection (unlike ax.25 packet), an ARDOP port must be allocated to a user before making connects. This is done using the ATTACH command. So if your ARDOP port is BPQ32 port 2, enter

ATTACH 2

Possible responses are:

#BPQ11:GM8BPQ-2} Ok

#BPQ11:GM8BPQ-2} Error - Invalid Port   // Port is not an ARDOP port.

#BPQ11:GM8BPQ-2} Error - Port in use   // Port is in use.

Once attached to a port, you can issue commands to the Virtual TNC. See the documentation for the Virtual TNC for a list of commands. Additionally, the "D" command disconnects and releases the TNC.

ARQ Mode.

Connections are initiated using the C command (not CONNECT as shown in the TNC Documentation).

FEC Mode.

FEC mode is initiated by entering the FEC command after ATTACHing the port.

Once this command is entered, anything typed will be transmitted as an FEC datagram, preceded by the user's callsign, and will be displayed by any other stations in FEC mode. As the protocol is not able to correct all errors, packets may have some corruption.

While in FEC mode any ADROP ID packets will also be displayed.

Use the "D" command to exit FEC mode.

An ID Packet and CWID (if enabled) will be sent every 10 minutes and on leaving FEC mode.