I did this about a week ago… and just finally got to documenting it.
I bought a pack of “beginner parts” awhile back. One of those parts, was a 7 segment LED display. After checking around the web, and the Netduino forums, I found that the simplest way to do this (and the preferred approach) is to use a shift register.
Well, I checked my parts boxes… and didn’t have one. Specifically, I was looking for a 74HC595. Nope… not a single one (that issue has since been remedied, and I know have several in one of the parts boxes).
So, I decided to wire up the display using just the pins from the Netduino. For this simple project, the 20 pins available on the Netduino are more than sufficient.
One of the things you have to do when wiring direct to the Netduino, is put a resistor on each leg of the LED display. So, I dug through my box, found a pack of resistors, and picked out 8 of the same type. I used a “yellow, brown, black” which I believe is a 41 Ω ± 5% resistor.
I do have control of the decimal point too.
In this project, I also put in a small potentiometer. This will control the speed of the numbers. Every time the display starts over at 0, it reads the pot to see how fast to display.
My son wanted it to display letters too. So, after explaining the limitations of making letters (using graph paper from my trusty Makers Notebook), we figured out we could make a few letters. It now counts from 0 to 9, then A to F.
Here is the video showing it counting at a moderate speed. It’s not the best quality, sorry. I just have a small PowerShot digital camera.
Forklift stacks pallets on the correct shelf, dependent on colour. Video Rating: 4 / 5
Introducing the first robot which uses LEGO NXT components (motors, wheels, …) and which is not driven by the standard NXT “brain” but it is instead driven by Arduino ( www.arduino.cc ). More information: www.arduino.cc www.scribd.com www.scribd.com Comment here: www.arduino.cc
This robot is inspired by tarribas’s project. www.youtube.com LEGO Mindstorms NXT version of ballbot powered by nxtOSEK. lejos-osek.sourceforge.net NXT Ballbot Simulation with MATLAB/Simulink : www.youtube.com You can download NXT Ballbot Simulink models and documents describe the controller algorithm at www.mathworks.com Video Rating: 4 / 5
Fifth in the www.motocube.com line of Ball Lego Ball throwers, this one manages about 30ft. Sadly I don’t have a 30ft large room to test it in, so this is all you get. Video Rating: 4 / 5
This project was built using one LEGO MINDSTORMS NXT (8527) kit, and one LEGO Power Functions Bulldozer (8275) kit, plus two LEGO adapter wires (and one rubber band). Video Rating: 4 / 5
A fully automated/motorized theater inspired by the recent LEGO Pirates theme. A detailed “Behind The Scenes” movie will follow. Stay tuned (…or even better subscribe now)! Visit web.me.com for more pictures. The Pirates and the NXTfied Theater: – One Intelligent NXT Brick – One NXT Rechargeable Battery – Three NXT Servo Motors – One NXT Light Sensor – One NXT IR Link (HiTechnic) – Two Power Functions IR Receivers – Two Power Functions Light Sets – Four Power Functions M-Motors – One Power Functions XL-Motor – Three Power Functions Battery Boxes – Three Power Functions Extension Wires …plus some more LEGO bricks and pieces Special thanks to my wife for the idea of flying seagulls! I have adopted this “NXTfied” expression from my LEGO bro from Canada ( bazmarc/bazmati, www.youtube.com ). Thanks bro!
