Configuration options

If you already have a FastCLock EX‑FastClock has a number of couple of configuration options which allow you to connect your own clock to a EX‑CommandStation.

The various configuration options are outlined below

Connecting your own FastClock

Connecting via Serial

Connecting via Serial is the simplest option if available.

• Run a dupont cable from the TX pin on the arduino to a RX pin on the EX-CommandStation. It is not usually necessary to run a cable from RX to the TX on the EX-CommandStation as the FastClock is not receiving data back.

• Find the Serial defines in the config.h file (or copy config.example.h to config.h if you dont have one), locate the following lines:

  //#define SERIAL1_COMMANDS
  //#define SERIAL2_COMMANDS
  //#define SERIAL3_COMMANDS
  

  and uncomment the appropriate one for the serial port you are using.

• Add the following code to your Setup() function:

Serial.begin(115200);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}

• Include the following routine within your code:

  void SendTime(byte hour, byte mins, byte speed) {
  
    int itime = (hour * 60) + mins;
    char buffer[20];
    sprintf(buffer, "<JC %d %d>", itime, speed);
    Serial.println(buffer);
  

• Each time the time changes call the SendTime routine as follows:

  SendTime(HH, MM, clockSpeed);
  

  where HH = the hour, MM = minutes and clockSpeed = the fast speed (e.g. at spped 4, 15 seconds represents a minute).

Connecting via I2C

Connecting via I²C involves a HAL driver file to the EX‑CommandStation as well as adding some code to the existing FastClock code. Follow the following steps:

• In the EX‑CommandStation code copy the file myHal.cpp_example.txt to myHal.cpp.

• Edit the file myHal.cpp and uncomment the following line near the beginning of the file

  //  #include "IO_EXFastClock.h"  // FastClock driver
  

• Uncomment the following line near the end of the file

  //  EXFastClock::create(0x55);
  

  0x55 (decimal 85) is the default address but needs to match that in the FastClock code (see below).

• Using Dupont connectors connect SDA/SCL/Gnd on the clock to SDA/SCL/Gnd on the EX‑CommandStation

• Include the following code in your FastClock code:

  Near the top of the sketch:

  #include <Wire.h>
  

  Within your Setup():

  Wire.begin(I2CAddress);
  Wire.onRequest(TransmitTime);
  

  Add the following function within the sketch

  void TransmitTime() {
      // send the data over I2C
      // send the time as <mmmm> as two bytes followed by clockspeed
      int timetosend = (HH * 60) + MM;
      byte TimeArray[2];
  
      TimeArray[0] = (timetosend >> 8);
      TimeArray[1] = timetosend & 0xFF;
      Wire.write(TimeArray, 2);
      Wire.write(clockSpeed);
  }
  

  In the function above HH is the time as hours (24hr. clock) and MM is the minutes.

• The CommandStation-EX will now poll the FastClock to request the time. The frequency at which it does so is influenced by the clock speed (i.e. on a slow clock speed it polls less often).

Next Steps

Now that you know how to connect your existing FastCLock, click the ‘Next’ button see how you use EX‑FastClock.