V1BOOST-STEPPER – Unipolar Stepper Motor

BoosterPack for the MSP430 LaunchPad

User’s Guide

Revised July 2012

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CONTENTS 1 Introduction ............................................................................................................................................................... 3

1.1 Overview ............................................................................................................................................................. 3

1.2 Features ............................................................................................................................................................... 3

1.3 Additional Information ....................................................................................................................................... 5

1.4 Contents .............................................................................................................................................................. 5

2 V1BOOST-STEPPER Demo Setup ................................................................................................................................ 6

2.1 Software and Project Setup ................................................................................................................................ 6

2.2 Program MSP430G2553 ...................................................................................................................................... 6

2.3 Hardware Setup .................................................................................................................................................. 7

3 Demo Experience ..................................................................................................................................................... 10

3.1 Unipolar Stepper Motor Demo Project ............................................................................................................ 10

4 Unipolar BoosterPack Hardware ............................................................................................................................. 12

4.1 ULN2003V12 Configuration .............................................................................................................................. 13

4.2 MSP430 LaunchPad Supply ............................................................................................................................... 13

4.3 Unipolar Stepper Motor Power Supply ............................................................................................................ 14

5 Eagle Documentation ............................................................................................................................................... 15

5.1 Eagle Schematic................................................................................................................................................. 15

5.2 PCB Layout......................................................................................................................................................... 16

5.2 Bill of Materials ................................................................................................................................................. 16

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1 INTRODUCTION

1.1 OVERVIEW

The V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack is an extension module for

the MSP-EXP430G2 MSP430 LaunchPad Value Line Development Kit. It is connected to

the MSP-EXP430G2 MSP430 LaunchPad through the 10 Pin headers located at positions

J1 and J2 on the MSP430 LaunchPad

Figure 1: V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack

1.2 FEATURES

The V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack features the new

ULN2003V12 Inductive Load Sink Driver from Texas Instruments. This inductive load sink

drive is compatible with 3V micro-controllers and logic interfaces which make it perfect

for driving inductive loads with a control signal from an MSP430G2553 microcontroller.

The V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack also includes two

uA78M00 Family onboard fixed voltage regulators for powering the unipolar stepper

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motor as well as the MSP-EXP430G2 MSP430 LaunchPad. Details of onboard fixed

voltage regulators are addressed in Section 4.

Connecting the 430BOOST_STEPPER Unipolar Stepper Motor BoosterPack does not limit

your design. It also includes a second row of 10 pin male headers for connecting other

MSP430 BoosterPacks such as the 430BOOST-SENSE1 - Capacitive Touch BoosterPack.

Figure 2: V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack connected to the MSP430

LaunchPad with the Capacitive Touch BoosterPack attached.

Full list of V1BOOST-STEPPER features includes:

ULN2003V12 Inductive Load Sink Driver configured to drive a 6/5 wire unipolar

stepper motor

DC barrel connector provides power to the unipolar stepper motor and MSP430

LaunchPad through two separate fixed voltage regulators

LED indicates power output to unipolar stepper motor

Two STDP slide switches allow users to toggle the power from both regulators

independently, allowing the choice of powering the MSP430 LaunchPad from

either the USB module or external DC power source

Second row of 10 pin male headers for connecting other MSP430 BoosterPacks

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1.3 ADDITIONAL INFORMATION

Refer to the ULN2003V12 Inductive Load Sink Driver datasheet for further design

information. This datasheet can be located through the following link:

http://www.ti.com/product/uln2003v12

Information about both onboard fixed voltage regulators can be located through the

following link:

http://www.ti.com/product/ua78m33

Additional information about the MSP-EXP430G2 MSP430 LaunchPad Value Line

Development Kit can be found on the LaunchPad’s Wiki page located here:

http://processors.wiki.ti.com/index.php/MSP430_LaunchPad_(MSP-EXP430G2)

1.4 CONTENTS

This is a list of what is required to operate the Unipolar Stepper Motor BoosterPack along

with its Demo Project.

V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack

MSP-EXP430G2 MSP430 LaunchPad Value Line Development Kit with MSP430G2553

Microcontroller

430BOOST-SENSE1 - Capacitive Touch BoosterPack

AC – DC Power Adapter (Input 100V – 240V AC 60/50 HZ) (Output 12V DC 1A)

8V Unipolar 6 Wire Stepper Motor

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2 V1BOOST-STEPPER DEMO SETUP

This section will describe setup of the software and hardware used for the demo

provided with the V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack. It is

important to follow these steps to begin developing applications for the MSP430G2553

microcontroller on the Unipolar Stepper Motor BoosterPack

2.1 SOFTWARE AND PROJECT SETUP

To run the Unipolar Stepper Motor BoosterPack Demo, Code Composer Studio version

5.20+ will need to be installed. Installation can be found at the following link:

http://processors.wiki.ti.com/index.php/Download_CCS

This installation will include the USB driver required for programming the MSP430G2553

device. After the installation follow these steps to import the Unipolar Stepper Motor

Boosterpack Demo Project:

1. Run Code Composer Studio V5 and enter an appropriate workspace for the

demo project.

2. Download the existing demo project located on the V1BOOST-STEPPER project

page at: http://e2e.ti.com/group/msp430launchpad/w/default.aspx

3. In the menu bar for Code Composer Studio, click on the projects tab and import

existing CCS project. Browse to find the downloaded project from step 2.

2.2 PROGRAM MSP430G2553

The following steps will properly program the demo project onto the MSP430G2553

device.

1. Insert the MSP430G2553 device into the 20 Pin socket on the MSP430

LaunchPad.

2. Ensure that the J3 header on the MSP430 LaunchPad has all the jumpers

connected.

3. Connect the MSP430 LaunchPad to the computer through USB

4. With the Demo project open in Code Composer Studio, run the debugger. This

will program the MSP430G2553 device.

5. Terminate the debugger.

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2.3 HARDWARE SETUP

The Unipolar Stepper Motor BoosterPack uses an external supply to power the MSP430

LaunchPad and the unipolar stepper motor. WARNING: Improper setup of hardware for

the Unipolar Stepper Motor BoosterPack could result in damage to the BoosterPack,

MSP430 LaunchPad, or other attached boosterPacks. Follow the steps below to

configure the MSP430 LaunchPad, Unipolar Stepper Motor BoosterPack, and Capacitive

Touch BoosterPack for the Demo project.

1. Disconnect the jumpers on header J3 and J5 of the MSP430 LaunchPad.

2. Install the Unipolar Stepper Motor BoosterPack onto the MSP430 LaunchPad’s

10 pin male headers. If male headers are not installed on the LaunchPad, they

will need to be soldered on before continuing. When the Unipolar Stepper

Motor BoosterPack is installed, the DC barrel connector needs to be pointed in

the same direction as the USB port on the MSP430 LaunchPad. Please refer to

Figure 2.

3. Install the Capacitive Touch BoosterPack on top of the Unipolar Stepper Motor

BoosterPack as shown in Figure 2. The capacitive touch BoosterPack is oriented

in the same direction it would be relative to the LaunchPad for the Capacitive

Touch User Experience.

4. Install External DC Power Supply provided with Unipolar Stepper Motor

BoosterPack. This supply is an AC to DC power adapter that requires a 100 –

240V AC 60/50 Hz input.

5. Turn on the slide switches for powering the unipolar stepper motor and the

MSP430 LaunchPad. The on position for the slide switches is the furthest

position away from the external DC power Supply connector.

6. Install the 6 wire unipolar stepper motor into the 6 pin female header located on

the bottom of the Unipolar Stepper Motor BoosterPack. Figure 3 shows the

configuration of the unipolar stepper motor’s windings and supply taps.

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Figure 3: Configuration of Stepper Motor 6 Pin Header.

The 6 wire unipolar stepper motor should be connected according to Figure 3 and 4.

The center taps of both windings are attached to the unipolar stepper motors supply

Figure 4: Unipolar Stepper Motor Connection to 6 Pin Header.

The Final setup of the Unipolar Stepper Motor BoosterPack Demo project is shown in

Figure 5.

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Figure 5: Unipolar Stepper Motor BoosterPack Hardware Setup. Unipolar Stepper

Motor is plugged into rear header on V1BOOST-STEPPER Motor BoosterPack.

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3 DEMO EXPERIENCE

Demo Experience outlined in this section assumes all software and hardware setup was

done in section 2. This demo experience section will describe the operation of the

Unipolar Stepper Motor BoosterPack Demo Project.

3.1 UNIPOLAR STEPPER MOTOR DEMO PROJECT

The Unipolar Stepper Motor BoosterPack Demo Project demonstrates the operation of the V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack in conjunction with the 430BOOST-SENSE1 Capacitive Touch BoosterPack.

Once the power is activated to the MSP430 LaunchPad, baseline capacitive measurements are taken by the MSP430G2553. The demo then will wait in Full-Step Mode for the user to manipulate the motor by the capacitive touch. Movements around the capacitive wheel will correspond to varying degrees of movement by the motor. LEDs bordering the capacitive touch BoosterPack will light up and change positions in sequence with the progress of the stepper motor.

Figure 6: LED pattern while demo is in Full Step Mode.

Should the user touch the middle button for several seconds, the motor will toggle

between full and half step modes. Half step mode provides a somewhat lower speed,

but is smoother. Half step mode can be differentiated from full step by the LEDs that

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activate. Should half step mode be on, only the right-hand side lights will be activate

while full step will toggle the left- hand side.

Figure 6: LED pattern while demo is in Half Step Mode.

As a power saving feature, the motor will be turned off after a period of inactivity and all

LEDs on the Capacitive Touchpad will power down. This greatly reduces the overall

power consumption of the system. It should be noted that power saving mode will allow

the drive shaft to spin freely and should be disabled when the stepper is supporting a

load. Press the middle button on the capacitive touch to wake the demo from sleep

mode.

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4 UNIPOLAR BOOSTERPACK HARDWARE

The V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack board consists of three

main hardware subsystems.

ULN2003V12 Inductive Load Driver configured to drive 6 wire unipolar stepper

motor

UA78M33 Fixed Voltage Regulator used to supply MSP430 LaunchPad through

external power supply

UA78M08 Fixed Voltage Regulator used to supply 8V unipolar stepper motor

This section outlines these hardware features

Figure 8: Unipolar Stepper Motor BoosterPack Topview

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4.1 ULN2003V12 CONFIGURATION

The ULN2003V12 is a 16 pin device. It has 7 channels each containing a free-wheeling

diode for driving inductive loads. The ULN2003V12 is configured to the pins of the

MSP430G2553 Microcontroller as shown in Figure 9.

Figure 9: ULN2003V12 Configuration to Microcontroller Pinout and Unipolar Stepper

Motor.

Port 1 pins 4-7 are used to control the unipolar stepper motor. Channels 1-4 of the

ULN2003 Inductive Load Driver are used for stepper motor operation.

4.2 MSP430 LAUNCHPAD SUPPLY

The UA78M33 Fixed voltage regulator supplies the MSP430 Launchpad with a constant

voltage of 3.3V. Refer to the MSP430 LaunchPad Users guide for further information

about supplying the MSP430 LaunchPad with an external power source. The input

voltage comes from a external 12V 1A AC to DC power adapter. This is regulated to 3.3V

at the output of the regulator. A 0.1uF ceramic capacitor is placed across the output of

the voltage regulator to improve its transient response. A STDP slide switch is included.

This allows the user the ability to supply the MSP430 Launchpad through the Unipolar

Stepper Motor BoosterPack or through the USB connection on the LaunchPad.

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4.3 UNIPOLAR STEPPER MOTOR POWER SUPPLY

The unipolar stepper motor is supplied by a UA7808 Fixed Voltage Regulator. A STDP

slide switch allows the user to turn the power supply off and on. The output of the

regulator includes the same capacitor that was in the MSP430 LaunchPad Supply

regulator and also includes a LED indicator circuit as a visual indication that the supply is

on. It is possible to solder on different regulators for different sized stepper motors. If

this is done, the regulator, stepper motor, and ULN2003V12 datasheets will need to be

consulted to verify they are operating in approved ranges.

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5 EAGLE DOCUMENTATION

PCB Layout was created with CadSoft Eagle Version 6.2.0. Schematic, PCB Layout, and Bill of

Materials is addressed in this section.

5.1 EAGLE SCHEMATIC

Figure 10: V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack Schematic

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5.2 PCB LAYOUT

Figure 10: V1BOOST-STEPPER Unipolar Stepper Motor BoosterPack PCB Layout

5.2 BILL OF MATERIALS

Quantity Part Number Description

2 929400E-01-36-ND CONN HEADER .100 SNGL STR 36POS

2 S5602-ND CONN FEMALE 10POS .1" SMD TIN

1 S5442-ND CONN FEMALE 6POS .100" R/A TIN

2 CKN1779CT-ND SWITCH SLIDE SPDT .4VA SMD

2 490-1532-1-ND CAP CER 0.1UF 16V 10% X7R 0603

1 ULN2003V12 20V Inductive Load Driver SOIC

1 RHM1.2KBGCT-ND RES 1.2K OHM 1/2W 5% 2010 SMD

1 CP-102A-ND CONN JACK POWER 2.1MM PCB

1 uA78M08 IC POS VOLT REG FX 8V SOT223-4

1 uA78M33 IC POS VOLT REG FX 3.3V SOT223-4

1 * 5mm LED

1 ** Unipolar Stepper Motor 8V

1 SF-789 AC DC Power Adapter Input 100-240V Output 12V

* LED is used in series with 1.2K ohm resistor to indicate motor power supply is ON.

** Unipolar steppermotor should load ULN2003V12 according to specifications listed on its datasheet.