Model Train-related Notes (a.k.a. “blog”) -- these are personal notes and musings on the subject of model train control, automation, electronics, or whatever I find interesting.

2019-09-21 - Searchlight Car conversion to LED

Category Train

I’ve just finished this project:

The car itself is a Model Power HO Scale “Safety First #624 Searchlight”. It’s a depressed flat car with a nice & sturdy die cast metal construction. It’s really well done.

Jim got it for Randall and when we tried to use it, somehow trains started crawling when pulling the car.

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2019-06-15 - Cotton Belt 9389

Category Train

Jim gave me this engine, with the sole purpose of changing the horn. How hard can it be?

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2019-06-03 - Jupiter Steam 4-4-0 Engine

Category Train

Jim got this engine for Randall in commemoration of the 150th Anniversary of the Transcontinental Railroad.

My first attempts at doing that video were miserable as the engine would stop constantly at slow speed and I tried a few things to see if I could improve the power pickup.

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2019-01-20 - Mini Wifi Camera and Train Layout Usage

Category Video

I’m continuing my exploration of what we can do using these cheap small mini cameras when it comes to train layouts, and today’s subject is this mini pinhole wifi camera. How well does it work and what can we use it for?

Mini pinhole camera compared to an HO-sized gondola

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2018-12-09 - SQ23 Mini Camera for Cab Rides

Category Video

After trying the SQ12 camera, I moved on to its newer sibling, the SQ23. The goal is to use it to record cab rides. As this one has wifi, a secondary goal is to see if it’s suitable as a “live camera” e.g. to broadcast a ride view to a screen.

Cab ride filmed using SQ23 Camera

This is the SQ23 Camera I got from Amazon (can be found cheaper elsewhere, e.g. on Aliexpress), compared to my  Mobius Action Cam and the SQ12 camera:

From left to right: SQ12, SQ23, Mobius compared to an HO-size engine + gondola

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2018-12-01 - SQ12 Mini Camera for Cab Rides

Category Video

I’ve been doing all my “cab ride” recordings using a Mobius Action Cam. A few months ago I tried the RunCam 2 for comparison.
This time I decided to try one of the SQ “mini” cameras series for a change.

Cab ride filmed using SQ12 Camera

I got this SQ12 from Amazon:

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2018-10-12 - CMRS Touch Panels, continued

Category CMRS

This is a follow up on that proof-of-concept I made at CMRS about touch panels for the mainline.

I'd like to elaborate a few points, with some pros and cons, which I had been thinking about when I started the project. Upfront I want to make it clear I am not advocating for one solution or another. I am offering "food for thoughts", pros and cons, and matter of discussion. Some of the discussion involved industries or city names which are specific to CMRS’ layout. A map of it can be found in the link above.

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2018-10-01 - Cameras, OpenCV, and occupancy detectors

Category Train

A lot of my interests when it comes to model train layouts are all about automation. Automation can mean to make the trains move automatically but it can also mean to automate signaling -- displaying semaphores and search lights according to traffic on the layout. The common denominator for both is block occupancy detection, namely to know where trains are on the layout.

An early prototype of camera-based block detection

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2018-09-15 - NCE AIU01 and Motion Sensor

Category NCE

As previously discussed, on the Randall layout, visitors press a button to trigger the trains’ automated sequence. Soon enough, we added a sign asking people to be nice with that button. The sign has nothing to do with the actual electronics behind nor the automation, not even the button itself. Both the button and the software are sturdy enough to survive any abuse.

And abuse there is. The abuse is simply… social. Kids hammer that button like there’s no tomorrow. Does it make trains run faster or more frequently? Nope. One would hope it would be a good exercise in parenting in teaching kids to be reasonable and treat common property adequately, but alas, no.

Eventually Jim and I had enough of it and I decided we could simply use a motion sensor as trigger instead of a hardware button. Back in March, I built this prototype:

The original design for the motion sensor was to use an ESP32 with an HC-SR501. The ESP32 would be used to send a sensor activation command to JMRI.

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2018-09-02 - Digispark Tiny

Category Arduino

The Digispark Tiny is a probably the most basic and compact Arduino-like I’ve worked with. It’s about the size of an USB A plug. It is powered by an ATTiny85 and offers 1-5 I/Os depending on usage (typically 2-3).

(image source:

Kickstarter Date: 2014.

Example of the Digispark Tiny connected to an USB OTG with a PIR sensor:

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