Week 13 Output Device

by Moritz Begle

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Posted on May 12, 2013 at 15:00 PM

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Stepper Motors

The aim of this class assignment was to create a output device and program it The tuturials and general informations can be found "here"

Working towards my final project I decided to order 3 Nema 17 Stepper Motor (cookinghacks) to move my camera dolly in 3 axis. MY goal of this week is to make a single steppermotor work and combine all three of them with an input device in the networking class.

Bipolar vs. Unipolar

A Unipolar Stepper Motor is driven by powering all the lines and iterating which of the four drive channels is grounded. The motor will align itself towards the grounded channel statically until it is switched high and the next channel is grounded. 5-lead stepper motors are also unipolar, they just have one power line instead of two.

A bipolar motor has two windings, and thus four leads. Each winding can carry a positive current, a negative current or no current. This is indicated in Table 1 by a ‘+’, a ‘–‘ or a blank.

Nema 17 Stepper Motor

This little motor packs a powerful punch at 76 oz of torque! With a 4 conductor servo connector.

Shaft Size: 5mm

Torque: 76 oz-in

Step Angle: 1.8

DC 1.68 A/Phase

30" Covered Leads

4 Port Connector Standard

hello.stepper.bipolar.44.

Eagle

Based on the hellostepper44 i was drawing the circuit in Eagle. As the A 4953 Bridge was not in the library available I used a 8 SOIC Mosfet instead. The 5V regulator had a flipped pin order in the board view which had to be rearranged manually according to datasheet of the regulator. For some reason i couldn`t manage to make the 5v 1A regulator work so I switched to the SMD version.

Programmed: Arduino -> Fab ISP External powersource: 12V After testing a lof of basic sketches trying to make the steppermotor run we went back to the original sketch of Neil which can be found "here" & with the help of Guillem Camprodon & Francisco Sanchez we finally managed to make the steppermotor work. The the arduino file can be found "here"

Programmed: Arduino -> Fab ISP

External powersource: 12V

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