Yes Sir, I can boogie!

I’ve been meaning for ages to get my turtle* project back up and running, and having put the quad siblings to bed for a while, I’ve finally had time.

Turtle

Turtle

By using a B+, I finally have enough GPIO pins to drive the stepper motors directly via 8 pins and mosfets rather than using the 74HC595 serial to parallel latch.  That’s simplified the circuitry and software a lot.  I’ve also turned the turtle into a WAP.  Finally, I’ve swapped batteries from unregulated 2S LiPo to a 2.4A phone charger bank.  This gives just about enough power – the 2.1V battery bank shown in the picture didn’t work – the motors drew enough current to trigger a safety switch in the battery.

I’m hoping to do a tutorial at the next Cotswold Jam, starting at a flashing LED and ending in a robot in 10 easy steps.  In the meantime, just watch her boogie!

Turtle boogie! from Andy Baker on Vimeo.

P.S. For a giggle, watch the original “Yes Sir, I can boobie” on youtube.


*A turtle should really have a pen controlled by a solenoid to leave a trail as it wanders. A more useful implementation for the modern era would be as the base for a laser cutter, or 3D printer: consider attaching the stepper motors to a fixed base at 90° to each other independently manoeuvring a suspended platform around underneath a fixed position laser or molten plastic feeder?  It’s only a different LEGO layout from what the turtles doing now.

In fact, my next project, piPlotter, has just been conceived, using the turtle motors to move a Raspberry Pi 7″ touch screen running a draw application with a stylus touching the screen to draw out the movement.  More of a LEGO project than a RPi project, and a lot more fun as a result.  Oh, and cheap too!