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RTB_D20

Real-time Bus (RTB) Kicad_Libs Apache License 2.0

The D20 decoder is a double sided mobile decoder with NEM-651 connector. The decoder is designed to integrate into the RTB digital control infrastructure.

See also
User Guides


The decoder has the following features,

  • NEM-651 connector
  • 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
  • Double sided
  • Dimension: 14 x 8 mm
  • 7-20V track voltage
  • heartbeat LED
  • adjustable max motor current (default 300mA)
  • adjustable max AUX current (default 500mA)
  • over temp protection
  • Function output: LF/LR (dimmable, 1.4kHz) open drain
  • Function output: AUX1/AUX2 (dimmable, 1.4kHz) open drain and logic level (3.3V)
  • Function output: AUX3/AUX4 logic level (3.3V)
  • optional external buffer capacitor (max. 1500uF)
  • <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, 0402 and 0201 parts. Reflow soldering is mandatory.

PCB

  • 6-layer PCB, FR4, 14 x 8 x 0.8mm (double sided)
  • CPU: AVR64DD28
  • Motor bridge: DRV8231
  • Connector: NEM-651

Kicad

Schematic | Layout | Gerber

Dependency

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

Firmware

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

Example: D20F0001.hex

Description
pcb Name of matching hardware (D20)
code Type of code contained (R=rom, B=bootloader, F=flash, U=bld update, P=UPDI factory code)
version Release version (####)

Firmware files

Images

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YouTube

Some YouTubes to see the D20 decoder in action.

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