Arduino Repeater Controller

Overview

The Arduino Repeater Controller (ARC) is meant to be a set of 1 to 7 boards that can be used for a repeater controller for up to 4 different repeaters. The repeaters may be configured as 4 completely independent repeaters managed by one Arduino, or as a linked repeater system, via the Multiplex Shield.

Each Interface Shield connects to one radio. In addition to the minimum necessary lines to connect to the radio, a few additional I/O are provided to allow fan control, input sensing, and voltage or current measurements.

A Voice Shield allows the controller to talk, although the audio can only be routed to one Interface Shield at a time.

The Telemetry Shield has a number of analog and digital inputs, and can also monitor various Interface Shields (or perhaps request parameters from the main controller that the Interface Shields have passed down). This would send AX.25 packets out on to the APRS network that contain various health information about the system. It may be possible to provide control and programming of the ARC, but some sort of security would be required. The Telemetry Shield can also announce data via CW or with voice (if the Voice Shield is present).

The Multiplexor Shield takes audio from 1 to 4 of the Interface Shields, and allows it be routed to another. This would allow IS #1 to be linked to IS #3 (perhaps connecting the 2M repeater to the 6M repeater), and IS #2 to be linked to IS #4 (70cm to 10M). The Multiplexor Shield is also required if the Voice Shield and/or Telemetry Shield is used.

Architecture

The Arduino talks to each ARC shield through an I2C bus. Each IS presents an identical interface at a different address. I2C registers exist for querying inputs (CAS, buffered input lines, analog inputs), setting outputs (PTT, open-collector outputs), setting audio levels, etc.

Interface Shield

• Features

• DTMF encode/decode
• PL encode/decode
• Digital level controls (no knobs!)
• 3 buffered inputs
• 3 open-collector outputs
• 3 A/D inputs
• DB-15 interface to radio
• Private intra-board audio bus
• On-board micro for signal consolidation to I2C

• Interface lines to/from radio

• RX audio + ground
• TX audio + ground
• CAS
• PTT

Multiplexor Shield

• Features

Voice Shield

• Features

Telemetry Shield

• Features

• AX25 packet format
• 1-Wire bus for DS-1820's
• Voice (?)
• Can directly connect to telemetry radio
• Remote control via AX-25(?)

• Security issues
• More complicated protocol

Intra-Board Bus (IBB)

• RX1-4 Audio
• TX1-4 Audio
• Voice Audio
• Telemetry Audio
• I2C Bus