The DS104 Lnet I2C Interface is a versatile LocoNet-compatible I2C interface designed to offer maximum flexibility for model railroad applications. Depending on configuration, the DS104 can operate as:

• Occupancy / sensor decoder
• Relay / switch decoder
• Servo decoder
• LED / signal decoder

It may be one of the few systems — if not the only system — capable of combining all these functions within a single device.

Origin & Philosophy

The modelrailelectronics.com developments originated within a young model railroad club that wanted to build an H0 layout for both 2-rail and 3-rail users, starting with a very limited budget and few members.

Initially, existing DIY products were tested, but based on their experiences, the club decided to design its own products.

Because these designs are DIY-based and the development has no profit motive, the resulting products are very affordable compared to commercially available alternatives.

Modular I2C Expansion

The DS104 features two I2C connectors, allowing any combination of compatible modules to be connected:

• DS201 current detection module
• DS202 mass detection module
• DS203 relay module
• DS204 sensor module (in development)
• DS205 reverse loop module (in development)
• DS206 switch module (in development)
• PCA9685 PWM module

When using the PCA9685 module, both servos and LEDs/signals can be controlled. The DS104 supports standard switch commands for signals as well as more efficient aspect commands, helping reduce the number of LocoNet addresses required per signal (depending on your model railroad software and command station combination).

If your command station does not support a LocoNet bus, you can add connectivity to your computer using our DS101 Lnet USB Interface & Monitor.

DS-Configurator App

Configuration of the DS104 Lnet I2C interface is handled via our DS-Configurator v1.02 app, available for:

• Windows
• Linux
• macOS

The application is multilingual by default and can be set to: English, Dutch, German, French, Spanish, or Italian.

We are currently preparing a user manual for DS-Configurator and welcome reviewers — especially for translation verifications.
Meanwhile you can read more about DS-Configurator on the DS-Configurator page.

DIY concept

All DS projects are supplied as standard DIY kits, including the printed circuit board and all required components. With the proper tools (see the “How To” page) and a bit of practice, these kits can be assembled even by less experienced hobbyists.

If you prefer not to build the kit yourself, fully assembled and tested units are available upon request.

Testing & feedback

Although we continuously test our products, additional real-world feedback is always welcome to further validate the correct functioning of the DS104 sketch and supporting applications.

If you are interested in participating in testing or reviewing, please contact us to discuss the possibilities.

LocoNet® is a registered trademark of Digitrax, Inc.