Back in the day of NXT’s etc, I spent most of my time programming the pBrick in RobotC, being a iOS developer(ObjectiveC), it felt right for me. However Lejos always kept popping up with some awesome features. Move forward to today and the EV3, for my needs (Mobile connectivity, vision processing) Lejos is the clear winning platform to take your EV3 to the next level. I find it a lot easier now especially since I do Android development as Lejos is in Java.
Lejos 0.9.1 brings some super exciting features to the table, but don’t take my word for it, please check out Lejos 0.9.1
So here is a prototype of my latest project, the LEGO Wheelchair which is capable of moving a 90KG person around a room using just LEGO Mindstorms, LEGO Technic and Rotacaster multi-directional wheels. This is still a prototype and under constant development however I really wanted to let people see what I have been up to.
My wife giving version 0.8 a test drive.
Me having an initial go on version 0.5.
The lastest version uses 6 LEGO Mindstorms NXT’s for moving and 1 NXT(master) for controling the direction. Each of the driving NXT’s has 2 NXT motors attached to it and 2 touch sensors used to control direction. The master NXT has 4 touch sensors connected (forward, back, left and right) and 2 motors to switch on the drive touch sensors. It is programmed in RobotC.
One of the next things on the list is to add remote control to the wheelchair using an Android device. The chair is controlled via 1 NXT, this will be very straight forward to control via bluettooth.
At the start of June there is a small LEGO railway show at the Buckinghamshire Railway Centre. The first year I went I did a display of LEGO pneumatic engines which I really enjoyed building. This year I have decided to bite the bullet and do something train related! Dont worry, I am not going to the dark side.
Below is a simple train demo which uses the LEGO Mindstorms NXT to control 2 9volt trains. I actually really enjoyed creating this, all I need to do now is actually make some trains!
This has been programmed in RobotC and uses 2 light sensors and 2 touch sensors to detect and stop the train. NXT motor port A powers the main track loop. NXT motor port B and C power the part of the track that comes off the points as they are isolated. So if NXT motor port A & B are on, train 1 will move. If NXT motor port A & C are on, train 2 moves.
Please let me know if you would like further information.
As you may be aware I have been building a Robot called Wheeler out of old parts (old grey and RCX 9V motors etc). I was hoping to have it finished over the Christmas break but had hit a small issue with driving the wheels with the new weight of the body. Anyway what I managed to get up and running is the top half of Wheeer and the controller which is a Android phone (Dell Streak).
Mindsensors RCX Multiplexer
I was utterly impressed with the Mindsensors.com RCX Multiplexer and using Xanders driver suite (check BotBench) how fast I was up and running. I wish there was a way to run the RCX Multiplexer off the NXT power supply but thats a small thing compared to how useful it is. I wish I had 3 more of them so that I could control 16 RCX motors!
Android NXT Remote Control
So to try and work out how to control the NXT via Android, I stumbled across the NXT Remote Control project which is free to download. This uses Lego’s Direct Commands to control the 3 motor ports on the NXT. This means it bypasses your own code and you have no control over it. However, what I managed to do is reduce it down to a very simple program that sends messages to the NXT which you can deal with in your own program. In RobotC, it sends messages that are compatible with the MessageParam command and so you can send a message ID and 2 params to the NXT and deal with them in RobotC anyway you want to.
Code will be available soon once I have tidied it up 🙂