IMPORTANT Edit: A huge thanks to @Bill SCHONFELDER who has carefully put the calibration procedure through its paces. Bill spotted a problem that I had not come across which has now been corrected. The Blockly code has been updated, the GUI did not need changing.

Please remember that this code is for Windows based machines only and will not run correctly on an emulator on the Mac. For Linux or Mac OSX you will need to build the application from the source code using Processing. All of the files are available for you to do this in the single zip file attached.

Thank you Bill!!

OK. You have carefully followed the instructions on how to build Otto and have made sure that all the servos are centralised (set at 90 degrees) before you attach the horns. You are now at the very exciting moment where you check to see how Otto moves and dances and so you upload your first simple Blockly code.

:( What happened? Why did the legs and feet move out of position? Otto doesn’t look right and doesn’t move smoothly.

Do not be disappointed and do not worry! This is completely normal and happens in every Otto build. This is the stage where you need to adjust the central positions of the servos using a simple process called calibration. This will only need to be done once and then the correct positions will be remembered every time you turn on your Otto.

If you are unsure... (More)