My Homebrew D24 is a single-sided DIY mobile decoder featuring a NEM-651 connector. While it shares the exact same dimensions as the D16, it offers additional AUX channels and supports WS28xx LED connections. It is fully designed for integration into the RTB digital control ecosystem.
User Guides
- User Guide - DE
- User Guide - EN
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
- Single sided
- Dimension: 17 x 11 mm
- 7-20V track voltage
- heartbeat LED
- adjustable max motor current (default 300mA)
- adjustable max AUX current (default 500mA)
- over temp protection
- Function output: LV/LR/AUX1/AUX2 (dimmable, 1.4kHz) open drain
- Function output: AUX3/AUX4/AUX5/AUX6/AUX7 logic level (5V)
- AUX3/AUX4 can be configured to drive WS28xx chips
- optional external buffer capacitor (max. 1500uF)
- <10mA idle power consumption
- Firmware update over main tracks via DCC-R protocol
The current PCB layout uses SMD footprints with 0.5mm pitch and mainly 0402 parts. Reflow soldering is recommended, handsoldering will be difficult.
Note: The '5V zone' silk text can be misleading as the above test point is not 5V source but rather the UPDI interface.
- 6-layer PCB, FR4, 17 x 11 x 0.8mm (single sided)
- CPU: AVR64DA32
- Motor bridge: DRV8231
- Connector: NEM-651
Filename structure: { pcb }{ code }{ version }.hex
Example: D16F0001.hex
| Description | |
|---|---|
| pcb | Name of matching hardware (D24) |
| code | Type of code contained (R=rom, B=bootloader, F=flash, U=bld update, P=UPDI factory code) |
| version | Release version (####) |
| top | bottom |
|---|---|
 |
 |
Some YouTubes to see the D24 decoder in action.
This project is intended for hobby use only and is distributed in accordance with the Apache License 2.0 agreement.