This project is no longer supported by me.

It is kept here for those that have already purchased them.

If you are looking for a full featured dual solenoid DCC turnout decoder then use this one:

https://www.pcbway.com/project/shareproject/RT_DCC_Pulse_8_High_Power_Turnout_Decoder_with_capacitor_discharge_unit_ae884dd9.html

It provides control for dual solenoid turnouts up to 5A current draw.

Unless you want to connect this to a DCC-EX command station directly by I2C I recommend that you use either of these instead.

https://www.pcbway.com/project/shareproject/RT_DCC_Pulse_8_Turnout_Decoder_with_capacitor_discharge_unit_26697a2a.html

https://www.pcbway.com/project/shareproject/RT_DCC_Pulse_8_High_Power_Turnout_Decoder_with_capacitor_discharge_unit_ae884dd9.html

Both of the above combine the DCC controller and CDU into one board.

I no longer provide support for this board.

Model Railroad dual solenoid turnout driver.

This board is designed to drive dual solenoid turnouts such as the Marklin M track 5117, 5202, 5137, 5214, 5207 or 5128 on a model train layout. With or without a capacitor discharge unit (CDU).

The board can also be used to control any item that draws up to 500mA, eg. Solenoid Signals, turntable motors, level crossing gates.

The maximum current for any one output is 500mA, this is limited by the ULN2803 darlington drivers.

The RT CDUP 4 SMT is an add on to for an Arduino Mega (or Uno) Command Station running DCC-EX from dcc-ex.com. It provides control of up to 8 dual solenoid items, eg turnouts, signals, level crossings.

This connects to the Command Station via I2C, which allows you to place the driver board(s) closer to the turnouts and thus reduces the amount of wiring between the Command Station and the turnouts.

The Command Station interfaces with the MCP23017 module on the driver board using the extended GPIO pins as vpins in EX-RAIL.

Within DCC-EX EX-RAIL automation the solenoid turnouts can be detailed by use of the macro on the following page.

It is possible to have up to eight (8) of these boards connected to the Command Station by changing the I2C address of each board using the jumper pins.

#define SOLENOID_PULSE 5 //5 mSec // should be less than 50mSec

#define SOLENOID_TURNOUT(id,pc,pt,desc,ali,shadow)\

ALIAS(ali,id)\

PIN_TURNOUT(id,0,desc)\

PIN_TURNOUT(shadow,0,HIDDEN)\

DONE\

ONCLOSE(id)\

SET(pc)\

DELAY(SOLENOID_PULSE)\

RESET(pc)\

CLOSE(shadow)\

DONE\

ONTHROW(id)\

SET(pt)\

DELAY(SOLENOID_PULSE)\

RESET(pt)\

THROW(shadow)\

DONE

The macro is then invoked as would be done for a pin turnout.

SOLENOID_TURNOUT(id, vpin_close, vpin_throw, description, alias, shadow_id)

As an example this is one from my layout located on vpins 164 and 165.

SOLENOID_TURNOUT(1000, 164, 165, "Entry to parking track 1", TRN_PARK_1_ENTRY, 1001)

This then gives you an alias TRN_PARK_1_ENTRY which can be used in THROW or CLOSE commands. Eg

THROW( TRN_PARK_1_ENTRY) or CLOSE( TRN_PARK_1_ENTRY)

More detailed description with images in description.pdf

Full construction instructions in details.pdf

References:

DCC-EX https://dcc-ex.com

EX-RAIL https://dcc-ex.com/ex-rail/

Solenoid Turnout macro by DavidMorph

https://discord.com/channels/713189617066836079/873794422993727568/1004923697586511954

RT CDUP 4 SMT pcb on PCBway

https://pcbway.com/project/shareproject/DCC_EX_Solenoid_Turnout_Driver_with_Capacitor_Discharge_Unit_8274534c.html

MCP23017 I2C Serial Interface - 16 bit I/O Expander Module example

https://ebay.com.au/itm/265734933121

https://www.aliexpress.com/item/32865063393.html

Youtube video of breadboard setup responding to a sensor input:

https://youtu.be/xnNRjlcMYPA

Youtube video of breadboard setup running as part of a script:

https://youtu.be/8_sHfRMoq30