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Table of Contents
DCC++ (EX)
Introduction
DCC++ is a Command Station based on the Arduino UNO/MEGA and a L298 Motor Shield.
- The DCC refresh stack size is 12, on a MEGA up to 50, with 127 speed steps and 28 functions.
- PT, Programming track
- POM, Programming On the Main. (Write only)
- 32 GCA Interfaces compatible I/O.
- DCC stationary decoder support.
- 2A Booster power.
Features
Extra features provided by the Rocrail implementation:
- Slot management with passive slot purge after 30 seconds idle and speed zero. (Can be changed in the setup.)
- Start of Day directly after establishing a serial connection.
General Setup
Sub-Library
Serial-USB
The baud rate is fixed at 115200.
The only thing to setup is to choose the right virtual serial port.
TCP/IP
A TCP/IP connection can be used if the Arduino features an Ethernet Shield.
The TCP/IP Port is fixed at 2560.
Options
Timeout
Serial read timeout in ms.
Slots
The number of slots is default 12. If using the MEGA it can be increased in the DCC++ sources.
The number of slots must be less or equal to the number of registers set in the DCC++ sources.
Slot Purge Time
The minimal idle time in seconds before a slot ist purged.
Sensor off delay
For pin 22..53 on the MEGA only.
Number of ms to wait before reporting an input as off. (The value should be a multiple of 10.)
The delay timer will be reset if an input gets high within this time.
System Info
Poll the main operations track current. (To show in Rocview's status bar.)
Echo commands
Echo switch commands for Arduino I/O only.
Swap gates
Swap the turnout and straight commands.
Reduce IDs
Reduce the generated switch and output IDs to 16. (0…15) Default is 256.
This option allows usage of an Arduino Uno with more than 45 devices addressed on DCC.
Serial device check
Some Windows configurations will crash at Rocrail server startup if the following option is not set:
I/O Setup
Add
Add a new I/O as defined with Type/Pin/Options.
It will be temporary created in the DCC++ CS.
Modify
Modify the selected I/O with the Type/Pin/Options settings.
It will be temporary modified in the DCC++ CS.
Delete
Delete the selected I/O.
It will be temporary deleted in the DCC++ CS.
Query
Query all defined I/O's in the DCC++ CS.
Save
Save all defined I/O in EEPROM.
Erase
Erase all defined I/O from EEPROM.
A new query is automatically issued.
Options
Output
Option | Bit | Value |
---|---|---|
Invert | 0 | 0 = forward operation (ACTIVE=HIGH / INACTIVE=LOW) 1 = inverted operation (ACTIVE=LOW / INACTIVE=HIGH) |
Restore | 1 | 0 = state of pin restored on power-up to either ACTIVE or INACTIVE depending on state before power-down; state of pin set to INACTIVE when first created 1 = state of pin set on power-up, or when first created, to either ACTIVE of INACTIVE depending on bit 2 |
Initial | 2 | 0 = state of pin set to INACTIVE upon power-up or when first created 1 = state of pin set to ACTIVE upon power-up or when first created |
Input (Sensor)
Option | Bit | Value |
---|---|---|
Pull-up | 0 | 1 = use internal pull-up resistor for the pin 0 = don't use internal pull-up resistor for the pin |
Usually no manual settings are required here. Rocrail automatically defines Arduino pins as input or output pins as soon as the pins of such a DCC++ CS are used for triggering sensors, turnouts or signals. For input pins, the option "Invert / Pull-up" is activated by default, i.e. the internal pull-up resistor is used.
Manual intervention is required, only in the case that other options than the default ones are to be used at startup. It is generally recommended that you first create all objects in the plan with the desired pins. Then Rocrail should be restarted and all commands of objects that use output pins should be executed once; because at startup all used input pins and, when executing a command, all output pins are created from Rocrail in the DCC++ CS temporarily. After that, all used pins are listed at "Query" and the options can be changed directly. At the end don't forget to save!
When changing the option "Invert / Pull-up", the following must also be observed: For outputs, the "Invert" setting here is only valid when starting Rocrail. To ensure that the outputs for turnouts or signals are always used inverted, the value in the field "Parameter" on the "Interface" tab of these objects must be set to "1".
Addressing
Sensors and Outputs are sharing the same address space; Avoid overlapping to prevent unexpected behaviour. |
Switches
Accessory
DCC Accessory.
Switches are addressed by the MADA scheme with decoder address and port. (DCC)
None Accessory
Arduino I/O.
Command | Output |
---|---|
straight | address + 0 |
turnout | address + 1 |
None Accessory Single gate
Arduino I/O.
Command | Output | Pin status |
---|---|---|
straight | address | OFF |
turnout | address | ON |
Sensors
Free Arduino pins can be used as sensor ports.
Outputs
Accessory
Outputs are addressed by the NMRA scheme with decoder address and port.
None Accessory
Free Arduino pins can be used as output ports.
To map the output for DCC the option "As switch" must be activated.
Signals
The accessory flag is used for Output commands.
Aspect numbers
Aspect number and Aspect Value can be used.
The aspect value represents a bit masks used for the four signal addresses.
G-ASH02
Type
Type code | Function |
---|---|
N | No operation |
O | Output |
I | Input |
Options
See: I/O Options
I/O n
The GCA I/O connector selection.
The button layout resembles the PCB layout.
PIN mapping
MEGA PINs | GCA connector | GCA I/O |
---|---|---|
22..36 (even) | I/O 1 | 1..8 |
23..37 (odd ) | I/O 2 | 9..16 |
38..52 (even) | I/O 3 | 17..24 |
39..53 (odd ) | I/O 4 | 25..32 |
The I/O connectors will match all GCA boards like GCA76, GCA77, GCA93, GC94, GCA173 etc
Jumper | Function | Remark |
---|---|---|
JP1 | Use 5V from Arduino board if placed. | Place only if the Arduino is powerless, otherwise it will reset itself. |
Files
Programming Track
The rail power must be set to on before using the Programming Track.
Do not forget to add the required jumper wire on the Motor Shield.
Trouble Shooting
Loco stops at max.speed
Set the number of Decoder steps to 126 instead of 128 on the Interface tab of the loco properties.