Technology

Holonomic LEGO Mindstorms Robot

Posted by on Aug 27, 2017 in LEGO, Project, Technology | 2 comments

A holonomic robot uses omni-directional wheels to drive and turn in any direction on the spot. Agilis is an example of an early LEGO holonomic robot. My model is much simpler and robust. Essential to all holonomic robots are the use of omni-directional wheel, such as the the ones from Rotacaster. I am using a compass sensor to allow the robot to be remote controlled on an absolute grid using Connexion’s Space Navigator. This 3D input devices can be mapped to the unique movements and rotations of a holonomic robot.

Read More

Tutorial on how to install and setup JInput on Mac OS X using Eclipse

Posted by on Aug 14, 2017 in Documentation, Technology | 0 comments

Using mouse, keyboard, joysticks and other input devices in your Java software is much easier using JInput. Unfortunately, the documentation on how to install and setup the software is short and difficult to follow. I was struggling for days getting it to work with Eclipse on Mac OS X 10.12.6. My first approach was to use Maven to install JInput. The excellent M2Eclipse plugin provides good support for Maven. Unfortunately, the pre-configured Maven Repository does not include JInput. I was unable to configure Maven/Eclipse to connect to The Central Repository to download JInput from there. Okay, I am not a fulltime Jave programmer and maybe it would become clear to me eventually. In the meantime I got it to work manually. I hope that this tutorial will help you in your project. I used Mac OS X and I cannot guarantee it will work on any other platform.

Read More

Easy LEGO Mindstorms Spirograph

Posted by on Jul 18, 2017 in Design, LEGO, Technology | 0 comments

Ever since I created the Spirograph Automaton I remained interested in drawing machines. For this years Christchurch Brick Show I wanted a more compact, easier to build version of the Spirograph. This time I used three motors instead of just one. Controlling the speed of both arms and the table was very easy this way. The Spirograph worked reliably throughout the whole show. The MinuteBot baseplate makes the construction even easier. The building instruction are available for LEGO Digital Designer. More information is available at Rebrickable.

Read More

Health Mate App Has Many Problems Since Nokia Took Over From Withings

Posted by on Jun 27, 2017 in Design, Technology | 80 comments

I like my Withings products and the the associated Health Mate App has been a pleasure to work with in the past. Recently Nokia took over Withings and also rebranded the whole product range. They also gave the Health Mate App a complete new design. What really upsets me is that they did not manage to come even close to the functionality that Withings’ original Health Mate app offered. I received the following reply from Nokia after asking them where my swim tracking data had gone:

Below you will find a list of known issues that we are in the process of fixing:

  • Health Mate isn’t sending data to Apple Health
  • Historical weight data not displayed in app
  • Navigation and UI issues with weight data graphs
  • Temperature and CO2 widgets missing
  • Luminosity, Noise, and Temperature data not displayed for Aura users
  • Normal ranges for Weight, BMI, Body Composition not appearing in the app
  • Swim data missing from the app
  • Inability to BMI widget to Dashboard
  • Inability to set or edit alarms on the Aura
  • Inability to log food or access the Nutrition screens
  • Inability to link Health Mate to MyFitnessPal
  • Inability to edit your Profile (email address, height)
  • Inability to set or change a Reminder
  • Inability to link to MyFitnessPal

Note that this is the bugs they are currently working on, after they already released a bug fix on June 23rd (version 3.0.2). Why do they release an incomplete and buggy app? Yes, it looks fancy, but how about focusing on the functionality first? This is not a good sign for Withings products. I really hope that Nokia does not ruin their beautiful products.

UPDATE: 8 August 2017

My Health Mate App updated automatically and Nokia put up a rather apologetic message. I can’t test if all the functionality they promised now really works, but at least some connection to Runkeeper is now working. My Swimming data usually is displayed twice, which remains a bit of a bummer.

Nokia apologises

Read More

Tutorial on how to install and run Java on Lego Mindstorms EV3 using Eclipse on Mac OS X

Posted by on Jun 4, 2017 in Documentation, Technology | 0 comments

We will be installing Java and the Eclipse Integrated Development Environment (IDE). This will allow us to develop your LEGO Minstorms EV3 software in Java and running it on the EV3 using LeJoS. Please let me know in the comments if you encounter any problems. I will try to keep this tutorial up to date.

You will need:

This tutorial will only get you started and you might want to dive much deeper into Java development for the EV3. These books might be useful for you:

My personal favourite for building amazing mechanism is Sariel’s book:

Read More

LEGO Compatible Medium Sized Thrust Ball Bearing

Posted by on May 24, 2017 in Design, Featured, LEGO, Technology | 0 comments

LEGO Compatible Medium Sized Thrust Ball Bearing

LEGO’s turn table has considerable friction and rotating a model at an exhibition for a whole day would ruin it. A thrust ball bearing is necessary to decrease the friction. I previously 3D printed a large bearing for my Unikitty. For this year’s exhibition I needed a smaller thrust ball bearing so I designed a new medium sized ball bearing. It includes liftarms to hold a worm wheel which results in a rotation ratio of 1:78. You can download the model from A360 and GrabCAD.

Read More