Attention

The Library in this code (VarSpeedServo) is no longer available on GitHub and is not supported by the creator, therefore the referenced code will not work. I’ll be updating this project with new code shortly. Sorry for the inconvenience

 

This project is a turnout control using Arduino in a simple configuration using push buttons, servos, LEDs, and relays. If you do not want a completely automated system, this may be the tools you will need for your model railroad.

Designed for any sized model railroad where you want to operate the turnouts on your own with push buttons. This can also be used with toggle switches with a slight modification to the code.

All components used in this project can be purchased through Amazon with the exception of the push button module which is a DFRobot product. A stand alone push button can also be used with the addition of a resistor. More information on this can be seen on another project in the Fritzing diagram for the PCA9685

Items Can be purchased through the Amazon Store page from the link at the bottom of the Page

A Test Sketch is provided to test all components individually before assembling the entire project. This is especially important for the Servos and The Relays.

With the Servo, you want to make sure your settings for the travel is correct and know weather you are driving the Hi or Low range for your straight position. In my example, I set all turnouts straight.

With the Relays, you want to insure you route the power for your frog correctly. Remember, the Relays are actuated with a LOW signal from the microcontroller. This is important, if you are aligning your turnout straight at startup, you’ll want to connect your frog lead to the common terminal and your feed wire to the NC terminal that is aligned with the straight section of your points. The NO terminal will go to the curved point feeder. Double check these connections for each relay individually before applying power to your track. You can use a multi meter or continuity checker for this test.

The Uno/Nano board does not have headers installed to be used as a shield for the Uno. Headers will need to be soldered to the underside of the board (not included).

A Nano has 2 additional analog input pins. All the other pins are identical to the Uno. A0 through A5 on both the Uno & Nano can also be designated as OUTPUT. This could give you additional pins for more outputs if needed, You can also leave these as analog inputs and use sensors for additional functionality.

If the push button module is not being used, and you prefer to use a stand alone PB, you will need a PULLDOWN resistor attached to Ground for this to operate properly. The Module has the necessary components already installed.