Wye Points Control

This is the cover page for the Wye Points Control project.

Introduction

A model train layout includes the following track known as a WYE,

Currently the four points are controlled via Macros in the NCE Controller. If for example the train wishes to go from the track known as Silos to Pommy Land the macro should set point 61 to Straight, point 60 to Turn (left) and point 63 to Right. (Note the control for 60 physically operates two points)

Project Objectives

The project objectives were to duplicate the NCE Macro operation using small mimic panels (6 required associated with each track). A micro controller takes the information and generates the required macro which is fed to the NCE Bus via an RS485 link.

The project modules

The project modules are:
Wye_Control_Buttons that includes 4 micro switches that request the path of the train via selecting the pointsNCE_Bus_Interface that monitors the RS485 bus.Wye Control Leds: A library that controls the LEDS on the mimic panel to indicate the chosen/active routes.
In this project Wye_Control_Buttons will request a macro that determines the points/turnouts to be set. NCE_Bus_Interface will past that request to the NCE Controller. Wye Control Leds will indicate what macro is selected.

The Code:

The final code must (i) include the required libraries: That is

#include <NCE_Bus_Interface.h>#include <Wye_Buttons.h>#include <Wye_LEDs.h>

(ii) Create objects of the three classes
NCE_Bus_Interface bus(6);Wye_Buttons but(4,8,A0,A1,A2,A3,A4,A5);Wye_LED led(2,10,9,3,7,6,5);
(iii) Add definitions for the desired macros. For example if the train is to go from the Mainline to Hardware Lane the macro is 183. There will be 24 definitions in total. These numbers are defined as part of the target system
#define MAIN_HARD_MACRO 183#define MAIN_SID_MACRO 184#define MAIN_ASH_MACRO 174#define MAIN_POMMY_MACRO 164
#define SILO_HARD_MACRO 181.................................................
(iv) The setup routine must initialise all the objects, set a default display (all LEDs off) and if desired initialise the serial port to allow debug or status messages
void setup(){  Serial.begin(115200);   Serial.println("\n-Macro Control-");  bus.begin();  but.begin( );  led.begin();  led.dump_LED(0xF0);}
(v) In the program loop the code reads the input buttons. If these change it requests a macro and activates the matching LED. This is performed using a switch function. There are 24 combinations in total
void loop()  {      bus.do_my_address();      int static save_req;    int request = but.read_buttons();    if (request == save_req) return;    save_req = request;    Serial.println(request,HEX);        switch (request){            case MAIN_HARD_REQ : bus.setMacro(MAIN_HARD_MACRO);                            led.dump_LED(MAIN_HARD_LED);                           break;      case MAIN_SID_REQ : bus.setMacro(MAIN_SID_MACRO);                            led.dump_LED(MAIN_SID_LED);                           break;      case MAIN_ASH_REQ : bus.setMacro(MAIN_ASH_MACRO);                            led.dump_LED(MAIN_ASH_LED);                           break;      case MAIN_POMMY_REQ : bus.setMacro(MAIN_POMMY_MACRO);                            led.dump_LED(MAIN_POMMY_LED);                           break;
       case SILO_HARD_REQ : bus.setMacro(SILO_HARD_MACRO);                            led.dump_LED(SILO_HARD_LED);                           break;                           ............            } }

Full Code

#include <NCE_Bus_Interface.h>#include <Wye_Buttons.h>#include <Wye_LEDs.h>
NCE_Bus_Interface bus(6);Wye_Buttons but(4,8,A0,A1,A2,A3,A4,A5);Wye_LED led(2,10,9,3,7,6,5);
#define MAIN_HARD_MACRO 183#define MAIN_SID_MACRO 184#define MAIN_ASH_MACRO 174#define MAIN_POMMY_MACRO 164
#define SILO_HARD_MACRO 181#define SILO_SID_MACRO 182#define SILO_ASH_MACRO 173#define SILO_POMMY_MACRO 163
#define HARD_MAIN_MACRO 183#define HARD_SILO_MACRO 181#define HARD_ASH_MACRO 171#define HARD_POMMY_MACRO 161
#define SID_MAIN_MACRO 184#define SID_SILO_MACRO 182#define SID_ASH_MACRO 172#define SID_POMMY_MACRO 162
#define ASH_MAIN_MACRO 174#define ASH_SILO_MACRO 173#define ASH_HARD_MACRO 171#define ASH_SID_MACRO 172
#define POMMY_MAIN_MACRO 164#define POMMY_SILO_MACRO 163#define POMMY_HARD_MACRO 161#define POMMY_SID_MACRO 162

void setup(){  Serial.begin(115200);   Serial.println("\n-Macro Control-");  bus.begin();  but.begin( );  led.begin();  led.dump_LED(0xF0);}void loop()  {      bus.do_my_address();      int static save_req;    int request = but.read_buttons();    if (request == save_req) return;    save_req = request;    Serial.println(request,HEX);        switch (request){            case MAIN_HARD_REQ : bus.setMacro(MAIN_HARD_MACRO);                            led.dump_LED(MAIN_HARD_LED);                           break;      case MAIN_SID_REQ : bus.setMacro(MAIN_SID_MACRO);                            led.dump_LED(MAIN_SID_LED);                           break;      case MAIN_ASH_REQ : bus.setMacro(MAIN_ASH_MACRO);                            led.dump_LED(MAIN_ASH_LED);                           break;      case MAIN_POMMY_REQ : bus.setMacro(MAIN_POMMY_MACRO);                            led.dump_LED(MAIN_POMMY_LED);                           break;
       case SILO_HARD_REQ : bus.setMacro(SILO_HARD_MACRO);                            led.dump_LED(SILO_HARD_LED);                           break;      case SILO_SID_REQ : bus.setMacro(SILO_SID_MACRO);                            led.dump_LED(SILO_SID_LED);                           break;      case SILO_ASH_REQ : bus.setMacro(SILO_ASH_MACRO);                            led.dump_LED(SILO_ASH_LED);                           break;      case SILO_POMMY_REQ : bus.setMacro(SILO_POMMY_MACRO);                            led.dump_LED(SILO_POMMY_LED);                           break;                                case HARD_MAIN_REQ : bus.setMacro(HARD_MAIN_MACRO);                            led.dump_LED(HARD_MAIN_LED);                           break;        case HARD_SILO_REQ : bus.setMacro(HARD_SILO_MACRO);                            led.dump_LED(HARD_SILO_LED);                           break;          case HARD_ASH_REQ : bus.setMacro(HARD_ASH_MACRO);                            led.dump_LED(HARD_ASH_LED);                          break;     case HARD_POMMY_REQ : bus.setMacro(HARD_POMMY_MACRO);                            led.dump_LED(HARD_POMMY_LED);                          break;
     case SID_MAIN_REQ : bus.setMacro(SID_MAIN_MACRO);                            led.dump_LED(SID_MAIN_LED);                           break;        case SID_SILO_REQ : bus.setMacro(SID_SILO_MACRO);                            led.dump_LED(SID_SILO_LED);                           break;          case SID_ASH_REQ : bus.setMacro(SID_ASH_MACRO);                            led.dump_LED(SID_ASH_LED);                          break;     case SID_POMMY_REQ : bus.setMacro(SID_POMMY_MACRO);                            led.dump_LED(SID_POMMY_LED);                          break;                                    case ASH_MAIN_REQ : bus.setMacro(ASH_MAIN_MACRO);                            led.dump_LED(ASH_MAIN_LED);                           break;       case ASH_SILO_REQ : bus.setMacro(ASH_SILO_MACRO);                            led.dump_LED(ASH_SILO_LED);                           break;     case ASH_HARD_REQ : bus.setMacro(ASH_HARD_MACRO);                            led.dump_LED(ASH_HARD_LED);                           break;                                 case ASH_SID_REQ : bus.setMacro(ASH_SID_MACRO);                            led.dump_LED(ASH_SID_LED);                           break;        case POMMY_MAIN_REQ : bus.setMacro(POMMY_MAIN_MACRO);                            led.dump_LED(POMMY_MAIN_LED);                           break;       case POMMY_SILO_REQ : bus.setMacro(POMMY_SILO_MACRO);                            led.dump_LED(POMMY_SILO_LED);                           break;     case POMMY_HARD_REQ : bus.setMacro(POMMY_HARD_MACRO);                            led.dump_LED(POMMY_HARD_LED);                           break;                                 case POMMY_SID_REQ : bus.setMacro(POMMY_SID_MACRO);                            led.dump_LED(POMMY_SID_LED);                           break;                            } }

Testing

The final code was tested on the model railway layout described previously.
By observation the points all followed the button/requests. However, there was a significant delay as illustrated by the following trace.
In the trace the 64 is one button request and 61 a second. The Send messages are part of the NCE_Bus_Interface Class.
07:37:36.090 -> RS485 Available07:37:36.090 -> 6407:37:37.966 -> Send 5C07:37:39.935 -> Send 5107:37:41.904 -> Send 5607:37:43.919 -> Send 5107:37:45.888 -> Send 4007:37:54.466 -> 6107:37:56.388 -> Send 5C07:37:58.357 -> Send 5107:38:00.326 -> Send 5607:38:02.295 -> Send 5407:38:04.311 -> Send 40
By observation there is almost 2 seconds between the "64" request being received and the Send 5C request to the NCE controller. There follows a approximately two second gap between each subsequent transfer. This equates to a 10 second delay before the complete request is transferred to the NCE Controller. These delays are built into the NCE_Bus_Interface Class and can be reduced significantly.
Where the delay was a real issue was that the LED changed state immediately the request was made not when the action was taken. There are a set of Signals that move with the points so these verify when the track is ready.
The delay in NCE_Bus_Interface will be adjusted to reach a more satisfactory compromise. No one expected the points to move immediately but a 10 second delay was considered unsatisfactory. See Step 15 in NCE_Bus_Interface_Development where the delay could easily be reduced from 20 to 8 which would reduce the response time to 4 seconds.