Sensor Less 3d Printed Robot
Tyree (he wears a tie and he has tires) actually smiles after he bumps into something (see video). Using an Arduino motor shield, he detects obstacles using the “more current into the motor means something is in the way” principle.
Tyree started out as a sketch and morphed into a real object thanks to Autodesk’s 123d software and a MakerBot Replicator 3d printer. Without the 3d tools, you can still learn how to make an active smile, tail wag, and sensor less control.
Step 1: Parts
Here’s the major parts:
Arduino Motor Shield
Gear motors (12 volt, 40 rpm) Jameco #253518
Tail motor Jameco #2128219
Smile solenoid Jameco #149762
DPDT 5 volt relay Jameco #139977
Two 1K resistors
Three 9 volt batteries and battery snaps
Seven AA batteries and holders
Heat Shrinkable Tubing
Body–For printable part list:
Time to start assembling the guts. Program the Arduino and build the circuitry on the breadboard.
I started with a Randofo tutorial and used code by dougstrickland as the basis for this operation. A couple of things need to be noted. Motor current increases when the motors first start turning and when they encounter resistance (a wall). I measure the current after the motors have had a second to get going–otherwise, I’ll alway detect high current and get into trouble. If you operate on carpet, the “analogRead” values may need to be higher since more work is required from the motors.
For more detail: Sensor Less 3d Printed Robot
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