Introduction

This project uses an infrared distance module, a stepper motor, a stepper motor linear slide, and an arduino nano to get detailed 3D scans of an object. The stepper motor is used to turn a rotating disk upon which the target object sits, while a stepper motor linear actuator slides the IR sensor along the vertical axis, getting the distance from the sensor of each point on the object. The entire aparatus is driven with an Arduino Nano and an A4988 stepper motor driver.

Components

Operation

circuit diagram

The brains of the operation is an Arduino Uno. The better choice would have been an Arduino Nano, with its smaller size and portability, but bad soldering skills got in the way of its use in this project.ar
Pins 2-5 are connected to the IN4, IN3, IN2 and IN1 pins on the 28BYJ-48 driver board, respectively. Pins 6 and 7 are connected to the STEP and DIR (step and direction) pins of the A4988 driver, which is used to control the linear actuator. Finally, the A0 pin is hooked up to the output of the SHARP GP2Y0A21SK0F.

The SHARP GP2Y0A21SK0F is instrumental to the operation of the scanner. It uses the relative luminosity of the IR light reflected off an object to determine its distance. We may exploit this in order to get a set of vertices that correspond to the object we are scanning.


The A4988 is neccessary to drive the linear actuator. There is no standard driver for the actuator that I ended up using, so I had to use a universal one (the A4988), although this does mean some snipping and soldering.


A 28BYJ-48 stepper motor and driver are used to rotate the pedestal upon which the target objects are placed. The spinning motion allows the IR sensor to get distance values for each point along the object being scanned.


A 12V 2 phase linear slide rail from Amazon allows the SHARP IR sensor to move along the Z axis, moving the sensor up and down. The downside is that the slide rail requires an external power source to function correctly, and will get quite hot after extensive use.