Short Project Description


Short Project Description


The concept of graphical programming enables teenagers and even younger children with creative access to computers. Scratch, a project of the Lifelong Kindergarten Group at the MIT Media Lab, provides not only the tool, but creates also a very inspiring environment for children, teachers and parents alike.
But sometimes creativity goes beyond creating "only" a program - physical interaction, tangible results become essential.

On the other hand, the Arduino project is quite famous and I'm impressed how well documented these microcontroller boards are, how easy they are to come by and how many slightly modified clones are around - all of them (Arduinos and clones) with a reasonable price tag. So it seems a good idea bringing Scratch and Arduino together.

This blog describes the advances step by step of setting up a robot controlled by an Arduino and easily programmed through a graphical enviroment. This project might be interesting to hobbyists, teachers, educators and parents (like me).

To allow for a maximum of creativity and flexibility the robot will use LEGO Technic / Education as the mechanical robotics platform.

Sunday 13 October 2013

Getting things started

Enough of grey theory! As the birthday of my son drew nearer, it was due time to get a move on. So I ordered necessary parts to implement an Arduino controlled LEGO Technic /  Education robot programmed with S4A for the sake of easy installation combined with a workshop materials well thought through.

Here's my shopping list for anyone who wants to tackle a similar project:
  1. First the heart of the robot: I ordered the ITeaduino BT to take advantage of directly attaching analogue and ditigal sensors to the electronic brick compatible connectors as well as to connect wirelessly to the Arduino clone via Blueetooth
  2. A small size breadboard and an Arduino + breadboard holder for desktop experimenting, an additional mini breadboard to mount directly to the robot, jumper wires, a battery case + rechargable NiMH batteries (6xAA) to provide power for a wireless robot and some electronic parts for first steps into "physical" computing
    • 3 red LEDs, 3 yellow LEDs and 3 green ones
    • 1 RGB LED
    • 10 resistors 220 Ohm
    • 5 resistors 10 kOhm
    • 1 potentiometer 4,7 kOhm lin.
    • 1 LDR (light dependent resistor) 5 kOhm (@1000 lx)
    • 3 push buttons
    • 1 shift register (SIPO) 74HC595
  3. To provide "real world" feedback I decided to order different distance sensors:
  4. As mechanical components a LEGO Eduction set 9632 and a LEGO Technic set 9390 are already available plus some other LEGO Technic parts of unknown provenience.To provide a "case" for the Arduino, an integration of servo motors as previously described and gears, I ordered some additional parts directly from LEGO
    • 4 Flat Panels - LEGO part no. 4621555
    • 4 Beam R. Frame 5X11 Ø4.85 - LEGO part no. 4540797
    • 4 Beam Frame 5X7 Ø 4.85 - LEGO part no. 4539880
    • 4 Gear Wheel T=24 - LEGO part no. 4211565
    • 4 Double Conical Wheel Z36 - LEGO part no. 4255563
    • 20 Connector Peg w. Friction - LEGO part no. 4121715

  5. Originally I thaught a standard servo would fit for integration into the LEGO rectangular frame (#4540797), but as the servo's axis has to fit into LEGO's grid dimension, I couldn't find a standard servo fulfilling this boundary condition. So I decided to go for mini servo fitted with an insert into this frame. To provide continuous rotation this type of servo motor has to be "hacked" as described several times on the internet; any particularities hacking this specimen I will describe in a later posting.

All in all, this list adds up to about 130 EUR - including delivery costs.

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