Automatic railway crossing (with Lego Mindstorms NXT)

[Hanso]

Hi folks,

It is one of my earlier builds that I want to share with you: an automatic railway crossing. The LDD sketch:

The barriers of the crossing are powered by two medium PF motors. I use two PF receivers: one to control the PF motors of the barriers, and one to control the lights. The two PF lights are crosswise connected to the PF receiver. By this means, I am able to get flashing lights and add sound. All of this above is controlled by a Lego Mindstorms NXT and an Hi-Technic HR link (in case you don't know: with the HR link you can translate Mindstorms commands into PF commands).

In the video below you can see and hear the result:

In the video below you can see the result in a small train layout. A PC application controls the two trains (both having a Mindstorms NXT + HiTechnic sensor to control the train) and also the Mindstorms NXT that controls the railway crossing.

Hope you like it.

/Hans

Edited May 17, 2015 by Hanso

[marook]

Looks great.

How does the crossing know when a train is coming? Seems like the one train signal is a bit earlier than the other.. ?!?

[dr_spock]

Nice work. It seems like a somewhat pricey solution with all those Mindstorm Intelligent Bricks.

[Hanso]

The PC application "knows" the train location on the layout. This is done by RFID tags under the rails (Codatex). The Codatex RFID reader reads the unique tag id and passes this information to the PC application. The application is flexible, that is: you can configure that if a specific card id is passed, the barriers have to close and at another card id they open again.

Hope this explanation helps.

/Hans

PS And yes, it is a quite pricey solution. But it is the perfect combination of writing software, playing with Lego and trains ;-)

Edited May 16, 2015 by Hanso

[WholeWheatLego]

I built a similar thing, but instead of using a RFID reader / computer software / IR stuff, I just had the train run over a section of track (one on either side of the crossing) that pushed down on a touch sensor that triggered the gates to go down until both sensors were released.

Sorry, I don't have any picks as my Lego stuff is currently boxed away at the moment.

edit: typo

Edited May 17, 2015 by WholeWheatLego

[qoucijure]

It seems like a somewhat pricey solution with all those Mindstorm Intelligent Bricks.

Edited May 17, 2015 by qoucijure

[Hanso]

Yes, it is pricey. But it is the only way to have the flashing lights and sound, all with standard Lego (okay, I count HiTechnic as true Lego).

/Hans

[Luke_likes_Lego]

So awesome!!

Hanso makes a good point:

PS And yes, it is a quite pricey solution. But it is the perfect combination of writing software, playing with Lego and trains ;-)

he's not just buying a crossing ....it's the whole experience.

Cheers,

LLL

Edited May 20, 2015 by Luke_likes_Lego

[Hanso]

As you state, it is the whole experience. Thanks for the nice compliment.

/Hans

[Hanso]

Added a new video with the automatic railroad crossing at Youtube:

Enjoy,

Hans

Edited June 7, 2016 by Hanso

[Patgeo]

Amasing work Hanso, and quite complicate for the average NXT Builder, but not for you!

You managed to achieve something realy nice and a lifelike resault!

[Hanso]

Amasing work Hanso, and quite complicate for the average NXT Builder, but not for you!

You managed to achieve something realy nice and a lifelike resault!

Thank you Patgeo for the nice words.

Hans