MSS signal management for turnouts

This is a self designed complex cascade PCB design and software project for my Freemo club I’m a member with. It is a cost effective solution coming in with a price tag of ~$30.

Cost

~$30 each. Block detectors are most likely needed on your local module. We are using ISE detectors.

Hardware build log

07-30-2026

After 2 horrible design errors, a viable version of the PCB is finally functioning to start full software development. Coldwater Junction module will be the development vehicle.

PCB version Log

• v1 2026.07.05 - In testing and software development. Board passes initial electrical checkout.

Software development

Read Inputs

• Read Diverge1 input
• Read all MSS bus inputs
• Read local block detectors
• Read local optical inputs

Processing logic

• Basic response to diverge inputs
• Full logic for MSS inputs
• Add local block detector integration
• Add optical processing

Drive signal masts

• Functions to drive points_upper, points_lower, main, and diverge. Ability to feed in clear, advance, approach, and occupied to all masts