Thursday, September 29, 2011

Save as... in LVLM

There's a feature in the NI's LabVIEW for LEGO MINDSTORMS NXT (LVLM) that I'm pretty keen on... it's that when you open LVLM it starts in a cut-down "LVLM" environment that removes many of the more advanced features from the toolbars, etc. and generally simplifies the interface. When you're ready, you just choose the "LabVIEW" environment and you've got access to the full range of LabVIEW features and menu items.

Unfortunately, one of the features that is hidden in the LVLM environment is "Save As..."!! Now, I expect that this was hidden because the LabVIEW "Save As... is indeed pretty darn advanced. For example, one of the options is to rename a file without creating a new copy. Another option allows you to create a new copy of your file, but lets you continue to work on the original copy.

It is, however, quite confusing as a newcomer to have the "Save As..." missing entirely. I'm pleased that a patch is now available that adds a much more familiar version of the "Save As..." to both environments in LVLM...

Windows
http://joule.ni.com/nidu/cds/view/p/id/2551

Mac
http://joule.ni.com/nidu/cds/view/p/id/2553 

Tuesday, September 27, 2011

GPSr comparison - Garmin v LEGO

I took my new GPS unit for a quick test run last week to compare it to my good old faithful Garmin Etrex Vista Cx. I set the NXT+dGPS to log its coordinate every 5 seconds, and the Garmin was left on its defult settings. Both units were positioned in between the driver and front passenger seat of my car. I waited until both units had a satellite fix before I started driving.
  • Yellow - LEGO NXT+dGPS
  • Blue - Garmin Etrex Vista Cx
At the start of the journey, the NXT takes an early lead... (click on the image to see it full size)


But at the end, it's the Garmin that finishes strongest.


Nothing particularly conclusive here, but nice to see that the results are comparable!

Monday, September 26, 2011

RoboCup Junior Australian Open 2011 - Photos and time lapse

RoboCup Junior Australian Open 2011 was held last weekend, the 24-25 September, at the University of Tasmania in Hobart. This was the 12th national RoboCup Junior in Australia, but the first time that it has been held in Tasmania - and it was awesome!!

I have uploaded a bunch of photos to Picasa Web Albums here.


I also produced a couple of time lapse videos using SAM Animation...



Tuesday, September 20, 2011

My new GPS unit...

In addition to playing with LEGO robots, I've been a keen geocacher for over four years. (In case you don't know, geocaching is a GPS-based treasure hunting game/sport/hobby/obsession.) As you might expect, there's always some discussion about the various pros & cons of the various GPS units that are available. With the advent of GPS-enabled smartphones, much of the discussion has been about how these compare with "real" GPS receivers (GPSr).

My first GPS unit, and one that I still use when I want a "real" GPSr, is a Garmin etrex Vista Cx, but these days I rarely cache without my iPhone 3GS (I mainly use the Geosphere app). Typically I go caching with both of these, but now I will have a third option...

This is a LEGO Mindstorms NXT with a Dexter Industries dGPS sensor. There are some guides for using this sensor with NXT-G, but I'm keen to see what I can do with LabVIEW for LEGO Mindstorms (LVLM). As a start, I downloaded the blocks for LVLM, wrote a quick datalogging program, and then went for my usual jog. When I came back home, I imported the data (with a little tweaking) in Google Earth. Unfortunately, I forgot to disable the sleep setting on my NXT brick, so I only got the first 10 minutes. Even so, the yellow line below gives a good indication of what the sensor is capable of doing...


I started on the eastern side of the map, and jogged anticlockwise around the hill. I set the NXT to collect the data every 10 seconds, and I'm impressed with how smooth the results were, over all. The start of the trip is a bit off, but this would be due to me hopping out of the car, and starting the journey without giving the dGPS a chance to settle down. The "wiggle" towards the ends of the log is no worse than what I get on my "real" GPSr from time to time on the same track.

Next, I'm going to do a side-by-side comparison of logging a journey on both my NXT and my Garmin, and then I've got to find a cache using only my new GPS unit!!