RTB_D23

The D23 decoder is a double sided mobile decoder with 8-pol NEM 652 connector. The decoder is designed to integrate into the RTB digital control infrastructure.

See also

• RTB_D12 - custom (Fleischmann V100)
• RTB_D13 - custom (Minitrix coach)
• RTB_D15 - custom (Minitrix V160)
• RTB_D16 - NEM651
• RTB_D20 - NEM651
• RTB_D21 - Next18
• RTB_D22 - Plux16

User Guides

• User Guide - DE
• User Guide - EN

Decoder features,

• NEM 652 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: 19 x 12 mm
• 7-28V track voltage
• heartbeat LED
• adjustable max motor current (default 500mA)
• adjustable max AUX current (default 500mA)
• over temp protection
• Function output: LF/LR (dimmable, 1.4kHz) open drain
• Function output: AUX1 (dimmable, 1.4kHz) open drain via NEM 652 connector
• Function output: AUX2/AUX3/AUX4 open drain via solder pads
• Function output: AUX5/AUX6 logic level (3.3V) or ZBCLK/ZBDAT (3.3V)
• onboard buffer capacitor (2x 100uF/35V)
• <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 0402 parts. Reflow soldering is mandatory whereas handsoldering near to impossible.

PCB

• 6-layer PCB, FR4, 18 x 12 x 0.8mm (double sided)
• CPU: AVR64DD28
• Motor bridge: DRV8231

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: D23F0001.hex

	Description
pcb	Name of matching hardware (D23)
code	Type of code contained (R=rom, B=bootloader, F=flash, U=bld update, P=UPDI factory code)
version	Release version (####)

Firmware files

UPDI

The fuse settings as well as the P-code (D23Pxxxx.hex) has to be installed by using UPDI.
Connecting the decoder via its track pins to a 5V(DC) power supply will boot its CPU. This way, its easy to program the fuses and flash.

Details

Fuse Setting	P-code Install

Images

top	bottom

YouTube

Some YouTubes to see the D23 decoder in action.

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