RTB_D12

My Homebrew D12 decoder is a drop in replacement for the original analog FLM (#7230) PCB. The decoder is designed to integrate into the RTB digital control infrastructure.

See also

• RTB_D13 - custom (Minitrix coach)
• RTB_D15 - custom (Minitrix V160)
• RTB_D16 - NEM651
• RTB_D20 - NEM651
• RTB_D21 - Next18
• RTB_D22 - Plux16
• RTB_D23 - NEM652

User Guides

• User Guide - DE
• User Guide - EN

Decoder features

• Fleischmann V100 PCB decoder
• DCC
  • DCC-A automatic logon
  • DCC-R protocol extension
  • Service Mode Programming
• Railcom
  • Channel 1/2
  • POM, xPOM
  • DYN: Speed, QoS, Track-voltage, Motor-current, AUX-current, Temp, Distance travelled
• 7-18V track voltage
• heartbeat LED
• adjustable max motor current (default 250mA)
• adjustable max AUX current (default 250mA)
• over temp protection
• Function output: LF/LR (dimmable, 1.4kHz), LED on PCB
• Function output: AUX1/AUX2 (dimmable, 1.4kHz) logic level (3.3V)
• Function output: AUX3/AUX4 open drain
• Function output: AUX5 cabin light, LED on PCB
• buffer capacitor 2x330uF
• <10mA idle power consumption
• Firmware update over main tracks via DCC-R protocol

Hardware

The current PCB layout uses SMD footprints with 0.5mm pitch and mainly 0603 parts. Reflow soldering is recommended whereas handsoldering will be difficult.

PCB

• 4-layer PCB, FR4, 0.8mm
• CPU: AVR64DA32
• Motor bridge: DRV8231
• Inrush limiter: R/D combination

Kicad

Schematic | Layout

The BOM is tailored to JLCPCB part#.

Dependency

:yellow_circle: Requires my Kicad project library RTB_SamacSys in the same directory tree.

Firmware

Filename structure: { pcb }{ code }{ version }.hex

Example: D12F0001.hex

	Description
pcb	Name of matching hardware (D12)
code	Type of code contained (R=rom, B=bootloader, F=flash, U=bld update, P=UPDI factory code)
version	Release version (####)

Firmware files

Images

YouTube

See the D12 decoder in action.

This project is intended for hobby use only and is distributed in accordance with the Apache License 2.0 agreement.