I thought I'd share a little project I'm currently working on:

At the beginning of the year, I received several parts from various driver’s cabs, including three Hasler speedometers that still work perfectly. I want to make two of them operational so that they can work with various simulators like Train Driver 2, Train Sim World, etc. The most complicated part is first converting the speedometer so that it can be digitally addressed at all.

The speedometer:


The speedometer is originally driven by a 35V 35W motor, which is not suitable for being controlled by a PC (it is possible, but cumbersome). The motor itself drives a shaft in the speedometer, which transitions into the mechanics of the speedometer and translates the speed.


I have now replaced the motor with a 12V geared motor, which can be more easily controlled with an Arduino and a motor driver:

Current status:

I have the speedometer working so that I can control it digitally and also pass on speeds. Now I still need a small companion software that can be started while playing, which takes the speed from the simulator and passes it to the speedometer. Reading the speed from TSW or TS Classic is relatively simple, but unfortunately, it's different with Train Driver 2. There is theoretically a COM interface that could output the speed, but unfortunately, it is currently defective, see https://git.ttsk.ngo/td2dev/simulator/-/issues/3480. Now I will try to do it with a desktop OCR solution that "recognizes" the speed on the screen. It's not ideal, but I can't think of another idea at the moment. Does anyone have any ideas? Plan B would be to read the Hasler tapes live from the game, but that's as unattractive as the OCR solution. I hope the API works again soon.

As soon as the software is running, I will mount the speedometer on a nice desktop stand and hide the electronics to make it look good. I will also convert a second speedometer accordingly and who knows, maybe I will sell the second one, but I'm not sure yet

I've already looked at your project, it's really impressive what you've done

It's a real shame that there's no clean API for projects like this. Of course I realize that only a few players need it, but it's a great way to implement great projects if you have the right data. As already mentioned, OCR is only a temporary solution because otherwise I don't know how to get the data easily. It works quite well in TD2 so far, even if you move the camera or are outside, you hardly get any incorrect data. Simrail still needs more fine-tuning. Of course, it would be nice if we had data on which switch is in which position, what the brake pressure is, etc. so that more instruments could be controlled accordingly. @Devs please give us a clean interface

PS this was published today
How was this implemented i wonder?