Locodoco/Loco Decoder

This Page is part of the Locodoco project. It currently only contains some vague notes about the planned version of the loco decoder.

List of (planned) features

Common on both Versions SUSI interface Support internal 3.3V logic levels (for RFM12b) measurement of rail voltage (= option for DCC integration) measurement of generator voltage (motor speed/load regulation) connector for IR transceiver seperate out/inletlets for each, motor-driver and logic power supply (GoldCaps) 4 GPIO Pins Processor: One out of Atmega8, Atmega168 and friends (all pin compatible devices)

Big version 5V power regulator, 3A 3 servo connectors >= 3A constant Motor current Socket for add-ons (shields) 2 N-Fets for high loads, 4A each, seperate rectifier to GND 4 additioal GPIO Pins Small version 1A Motor current Maximum dimensions: 22x60x10mm

Two Versions

Larger locomotives provide a "massive" amount of space and require some more Amps to drive their engine(s). While the big version of the decoder includes many features, the small version is a rather minimalistic approach.

The hardware design of both versions however is designed to be as flexible as possible, letting the user choose the components to use from a variety of parts. The Processor for example may be an Atmega8, which is rather cheap, or the more expensive Variant Atmega328.

Load regulation

A common feature among digital model railroad systems is load regulation and measurement of the actual speed of the motor. When performing scripted actions like (de)coupling cars on a certain point of the layout, it is essential to know the actual speed of the loco. I've done some experimenting with different circuits and documented the results in a small video.