Hi Mr Bob,

We have decided to stop the barcode work. Our idea is to make a vehicle to go down stairs like a slinkie. We hope you like this idea that we are creating.


From Miki, Lydia, Katiya, MBPS2

More bar code stuff

Hi Miki, Lydia and Katiya,

I hope you enjoyed Show Day. I had a little time to play around with making a bar code reader.

The first important key to success is to have a good bar code to start with. Here are two sheets, one colour and one black and white. For best results print them on a colour printer.



Here are some two programs demonstrating the core mechanic. After you have tried them out on your robot, try recreating them from scratch.

My motors are set to power 5 and the colour sensor is about 10 mm off the ground, at exactly a 90 degree angle.


Once you have mastered the core, you get to choose what to do next. There are lots of possibilities:

  1. Change the program to count lines.
  2. Change the program to count thin and thick lines.
  3. Add grocery items to the black and white bar code reader
  4. Play around with the numbers in the program to make it work more reliably.
  5. Try and get the code to work a different way than the way I have done it.
  6. Try triggering the timer using absolute levels instead of change of levels that I used.
  7. Experiment with the height of the sensor to see what works best
  8. Try reading the black and white lines with the sensor set to colour.
  9. Figure out a way to have more than 5 items using colour bar codes.
  10. Make the display on your cash register robot look better than my examples.
  11. Make the items scroll upwards on the cash register screen once a new item is scanned.
  12. Display ones and zeros on the screen – 1 for thick line, zero for thin line — like this: 0110101 (hint: try using the text block)
  13. Anything else you can think of.

I will post some links to YouTube videos below… you might get some ideas and be inspired!

Have fun,



Changed our idea

To Belliot


We have changed our idea to do a zombie dog that has two front legs and no hind legs. We will figure out how to make it move slowly and to make it groan while its staggering. We will use purple fabric put together to make our robot fit into it with out using glue, nails or sticky tape. If you could give us ideas on how to do this, it would be great.

Thanks, Isaiah

New robot from Boat Harbour

Hi everyone,

Here are some pictures of her team’s robot that Bo sent me by e-mail. It is a solidly built robot that will be able to do many challenges …… I am pleased to see you building, I am pleased to hear from you. I look forward to some videos.

Bob (Mr. E)

Barcode part 2

HI Mr E,

Today we recreated the program that we made last session and we were trying to figure out how to make different beeps on different lines. We can’t figure out how to do it but we had the idea of having a ‘if than do this’ block but we couldn’t find it. We are wondering if you have any suggestions on what to do. We were thinking that we need it to do the command ‘if number printed on screen is less than 22 then play beep’ to recognise the thin lines and more than 22 but less than 150 for the thick and to play a different beep.


From Miki, Lydia and Katiya.