A couple of years ago I started a thread on the forum which eventually led to a project to use an Arduino Mega to control Atlas switches on my layout.
The goals of my project were as follows:
- Control Atlas switches from both toggle switches on a control panel and from insulated rail sections (for non-derail operation).
- Prevent switch coil damage from continuous power when train is going through an insulated rail section.
- Control indicator LEDs that show the position of the switch and remember the position even when power is turned off to the layout.
I just finished version 3 of my project and I wanted to share a couple of pictures of my progress.
Here is a picture that shows the boards that can control 16 switches and 32 indicator LEDs (16 switches x 2 positions). The top right board is a shield that fits on top of the Arduino. It has 32 inputs coming from the toggles/insulated rails and 32 outputs going to the relay boards that control the switches. It also has 3 wires going to another board (top left) with shift registers to control the 32 LEDs. The bottom 4 boards are relays that send power to the Atlas switch coils.
Here is a picture of version 2, which could only handle 12 switches per Arduino. As you can see, I have eliminated quite a bit of wiring.
I've been very happy with the results. The 2nd version has been working without a problem on my layout for about a year, which is why I decided to go ahead with the 3rd version.
