Shipping delays - Our trackers are all assembled domestically, but we depend on various components from overseas suppliers and the Covid-19 outbreak is causing major disruptions for certain parts. Shipments are still trickling in and we're finding alternate suppliers, but delays of at least a few weeks should be expected.

The preliminary user's manual is now available for download. The USB driver INF file for Windows 8 and below can be found here

New Features

The Tracker4 is the successor to the OpenTracker and Tracker2 / Tracker3 series, and it represents a near-total software rewrite and a huge increase in memory and processor power.

Like its predecessors, the T4 is an APRS tracker, digipeater, and KISS TNC, and keeps all of the Tracker3's software features. Major new features include:

  • WiFi networking - supports 802.11b/g/n
  • Browser-based configuration, no special configuration software required
  • Telnet server for remote network access
  • Internal GPS receiver
  • Complete BASIC interpreter for easy scripting
  • RS-485 port with Modbus RTU support for interfacing with sensors, relays, and other devices
  • DTMF decoding and encoding, usable with macros and scripts
  • WAV file recording and playback capability
An external magnetic mount GPS antenna and WiFi antenna are included.

Pre-order notes

Some planned features, beyond those listed above, may not be complete when trackers start shipping. Those updates will be released as they're completed, and software updates can be downloaded and installed with a single click.

The connector layout on the production tracker will differ from what's shown here. The new revision replaces the 14-pin terminal block with a 10-pin terminal block and has the extra RS-232 port on a DE9 connector.

The Tracker4 is being developed in parallel with the new ADS-SR2 repeater controller and shares much of the same software. The tracker is in fact currently usable as a simplex voice repeater and includes many of the features of the existing ADS-SR1 repeater. The repeater functions may not stay in the final release of the tracker software, or those functions may become optional add-ons, but pre-order customers will keep at least those repeater functions that are already included.

Radio Cables

Radio cables are sold separately. We stock cables to connect the Tracker4 to many common radio types. Scroll down to the Tracker Cables in the Radio Cables category for a listing.

Cable compatibility guide

File system

20 MB of internal flash storage is available on the device for storing GPS tracks, telemetry readings, BASIC scripts, WAV files, and the like.


The Tracker4 has a mini USB type B connector and shows up as both a serial device and mass storage device. No special drivers are required for use with OS X, Linux, and Windows 10. Windows versions prior to 10 will need an INF file installed.


The Tracker4's WiFi module can function in access point, WiFi Direct, or client mode. Client mode is typically used to connect to an existing network, while AP and Direct modes can be used to connect with PCs and mobile devices away from fixed infrastructure.

Modbus RTU

The Modbus RTU protocol has been widely used in industry for decades and is supported by thousands of devices, including everything from simple relay boards for under $10 to high-end telemetry equipment. The RS-485 bus is capable of very long cable runs and has excellent immunity to electrical noise.

BASIC Scripting

Improved scripting support makes the Tracker4 extremely flexible and adaptable. The tiny scripting system in the T2/T3 series was useful for simple tasks, but tedious to use for more complicated tasks. The Tracker4 includes a BASIC interpreter based on an enhanced version of uBASIC with added string and floating point support, as well as additional commands for easy manipulation of APRS data and telemetry.

Modbus RTU and Dallas 1-Wire devices can both be accessed by the scripting system, allowing simple, easy-to-write scripts to perform a wide variety of automation and data transformation tasks.

Price each$139.00$124.00