KDM

Thank you so much for your help! Your program worked perfectly. I see now what I was doing wrong. Thank you again for your time in helping me with this program.

I'm not sure if I have a A or B block or how to get it? I have NXT 2.0.

I see what you are saying. How do you get the program to check if either of the switches is activated? I've tried posting a picture of what I've done so far but it didn't work. The way I wrote it was, the first switch lowers the bridge. Upon release of the second switch the bride goes back up. The problem I'm having is when the train comes back from the other direction. The switch comands between the two branches of comands get mixed up. If I could get it to read one branch at a time, it would solve my problem. It seems to read both at the same time. I'm sure it's an easy fix, if you know what you are doing. Thanks for your help.

Thanks for responding guys! The idea was for the bridge to stay up. As the train comes to the bridge, the bridge lowers and the train goes over the bridge. Once the train goes over the last pressure switch, it goes back up again. I'll try and post a picture of the program I've written. Any ideas to help out, will be greatly appreciated. I tried posting a picture of the program I wrote but it says the file was too big to upload. Not sure how to get that to work?

I'm a beginner at nxt programming. I built a train drawbridge for my lego city. I thought, I would try and use the nxt technology to make the bridge go up and down as the train crossed over the bridge. I put a pressure switch at each end of the bridge. One to tell the bridge to go up and one to tell the bridge to go down. It seems so simple but has become so frustrating. If train comes from one direction each time no problem. But if the train comes from the other direction the commands get confused. I did two series of commands, each by themselves work just fine. If I put them together, since I'm using the same switches, the program gets confused. I hope someone can help me with my problem.

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