My DCC-EX Prototype

[travis_farmer]

i have laid out my plans many times, and then changed them quite rapidly, so i will try to keep a running blog here of progress and ideas.

at present, my prototype runs off of a MEGA 2560 Core, development board. i use a Arduino Motor Shield, and a IBT-2 for the programming and main tracks. interface connection is via Ethernet, through a W5500 module, i think. power supply is a 16Vdc PSU for track voltage, and a buck converter for dropping the 16Vdc down to 5Vdc for the MCU power, and other logic and modules.
i have a 5U rack-mount steel project enclosure that i will house everything into. the main MCU, logic PCBs, and modules will mount on a piece of wood, via some plastic L-standoffs. it is my plan to get some sheet PVC and mount it on the front and back of the enclosure, after cutting out a large hole in both the back and front steel panels. that will aid in cutting holes for various connectors and such.

 

[travis_farmer]

so, my prototype is at a stage where i can alter it to make it electrically safe, without messing up too much.
track power will be provided by a RV PM3-? charger, adjusted to 15Vdc, fixed. this will pass into the enclosure with some sort of terminals. inside the enclosure, i will use a 12v-40v to 5v dc to dc converter to get VCC power. i will have fuses for various circuits, as well. master fuses for track power (one each for main and prog drivers), and 5v power, with sub-fuses for some 5v circuits.
this will eliminate the open power supply that is not super safe.

I have the PVC panel for the front panel, i just have to finalize some of the design before i cut any holes in the panel.

i have 3 screw terminals i can use for main and prog outputs, as well as the master power input, and i will need to properly label them. i will also need a hole to mount the 2004 LCD in place.

with there being zero AC line voltage inside the enclosure, it should be safer, and less likely to pickup interference.

i may use some of the 10awg wire (red + black bonded pair) to supply power to the enclosure, as well as carry it within the enclosure, where needed.

so i need to pickup the PM3-? charger, some fuse holders and fuses. sometime when i have some money available.

 

[travis_farmer]

I snapped a pic of my DCC-EX CS prototype. Mega2560 CORE main MCU board (bottom left), 2004 LCD (bottom right), Arduino motor shield for programing track (center right), IBT_2 motor driver for main track (upper right), and the W5500 Ethernet module (upper left).