The DLP™ 3D Printer Reference Design enables faster development of 3D printing applications utilizing
DLP platforms. This guide walks the user through the installation, operation, and recommended use
settings of the DLP 3D Printer Reference Design, as well as building the GUI and microcontroller firmware
from source code.
Related Documentation from Texas Instruments
DLPC350 Datasheet: DLP Digital Controller for the DLP4500 DMD, DLPS029
DLP4500 Datasheet: DLP®0.45 WXGA DMD, DLPS028
User's Guide: DLP®LightCrafter 4500™ Evaluation Module, DLPU011
User's Guide: MSP430x2xx Family, SLAU144
DRV8825 Datasheet: Stepper Motor Controller IC, DRV8825
If You Need Assistance
Refer to the DLP and MEMS TI E2E Community support forums
•Future Technology Devices International Ltd. D2XX Drivers 2.10.00
•Freesteel Z-level Slicer
Note: The DLP 3D Printer Reference Design installation and setup is written for users that are familiar
with navigating through Windows command line prompts and building executable binaries from source
code.
Note: The DLP 3D Printer Reference Design was created with the above listed versions of each software
tool. Using newer versions of the software tools may render the code inoperable, and it shall be up to the
user to make appropriate changes to the source code for compatibility.
Introduction to the DLP®3D Printer Reference Design
1.1The DLP 3D Printer Reference Design is a full hardware design enabling 3-dimensional printing of objects
from cross-sectional images from meshed models. The reference design includes a lightweight GUI,
electrical schematics, cable assembly drawings, and mechanical drawings to create the printer.
1.2Stereolithography
Stereolithography is an additive manufacturing method that employs a photo-curable resin. Exposing the
photo-resin to successive 2-dimensional object cross sections create the 3-dimensional objects a single
layer at a time. The resin, composed of monomers, cross-links when exposed to light of a sufficient energy
level. The cross-linking of the monomers generates a polymer chain, creating a solid material where the
resin was exposed. Stereolithography was traditionally achieved by outlining the object layer with a laser;
DLP technology allows an entire layer to be exposed at once by dynamically masking a broad light source.
1.3How the DLP 3D Printer Reference Design Works
The DLP 3D Printer Reference Design consists of a LightCrafter 4500 evaluation module, a translation
stage driven by a stepper motor, and a microcontroller at its core. The DLP 3D Printer Reference Design
utilizes the DLP Structured Light SDK to perform the printed image creation and layer sequence for
printed objects.
1.3.1DLP Structured Light SDK
A GUI on a host PC allows the user to upload the sliced object images to the DLP 3D Printer for storage
and exposure. The sliced layers are combined into composite images and uploaded to the LightCrafter
4500 along with their exposure sequence. The DLP Structured Light SDK prepares the layer images and
contains development modules for preparing image sequences. The SDK source code is made available
along with the GUI source code in the TIDA-00293 DLP 3D Printer design files package.
1.3.2 Photo-resins
A host of photo-resins are available in the SLA market, offered by a handful of commercial manufacturers.
Each resin has different physical properties lending themselves to specific applications. The DLP 3D
Printer is built with a 420 nm light source, which allows the use of any resin that is curable at this
wavelength or above. The resin used during the development of the DLP 3D Printer was sourced from
www.buy3dink.com
1.3.3DLP LightCrafter™ 4500 Evaluation Module
The DLP 3D Printer Reference Design uses a modified LightCrafter 4500 projector to expose the photoresin. The LightCrafter 4500 is modified with a 420 nm Philips Lumileds Luxeon®UV LED. The projection
optics are also modified to allow the projector to focus at shorter distances, enabling higher resolution
printed objects.
1.3.4 Velmex XSlide™ Translation Stage
The printed objects form on a platform that translates on one axis only. The translation stage lowers the
build platform a precise and accurate distance for each printed layer. This reference design uses the
Velmex XSlide, which accepts NEMA 17 or 23 sized stepper motors and has integrated limit switches. The
stage is highly rigid for it's small size to ensure repeatable positioning of the build platform.
DLPU025–September 2014Introduction to the DLP®3D Printer Reference Design
The DLP 3D Printer mechanical assembly is constructed from 0.25" thick aluminum plates to make the
structure as rigid as possible. The structure's role is to hold the orientation of the build platform/translation
stage, photo-resin vat, and projector tightly, in relation to each other, to reduce dimensional errors in the
printed objects. The mechanical assembly features an easily removable photo-resin vat.
1.3.6DLP 3D Printer Microcontroller
The DLP 3D Printer has to synchronize motor control along with exposure of the object layers, as well as
supply an interface with a front panel LCD screen and user buttons. An MSP430F2410 controls the
operation of the DLP 3D Printer onboard a stand-alone capable BeagleBone Black MSTP Cape. The
MSTP cape contains the microcontroller and a DRV8825 stepper motor control IC. The
MSP430/DRV8825 combination is capable of driving bipolar and unipolar stepper motors with phase
voltages between 8.2 V to 45 V. The DRV8825 can output up to 2.5 A of current at 24 V. The MSTP cape
must be modified by the addition of connections between the microcontroller and header pins. The
connections that must be added are highlighted in red in the cape schematic in the TIDA-00293 design file
package.
1.3.7 Front Panel User Interface
Users can interface with the DLP 3D Printer through a front panel once the print has been started. A 4-line
LCD screen with 20 characters per line displays information to the user such as the number of print layers
and the current layer in the print sequence. The LCD screen is controlled by the MSP430 through an
HD44780 controller. The front panel also has two buttons allowing users to interact with the printer, either
by responding to LCD prompts or pausing -- and even cancelling -- the print sequence.
www.ti.com
1.3.8DLP 3D Printer Graphical User Interface
Object layer images are uploaded to the DLP 3D Printer hardware utilizing a GUI. Object layer images
must be 912 × 1140 resolution due to the native resolution of the LightCrafter 4500. The images are
processed by the DLP Structured Light SDK into a firmware file containing the sequence of layer images.
The GUI takes a basic set of parameters from the user including: LED current setting, layer exposure time,
z-layer step resolution, resin settling time, and the directory where object layer images are kept.
1.3.9 Object Layer Images
Object layer images can be made by hand using a drawing utility, or created by slicing STL file models.
STL files are the de facto standard input file for 3D printers, and are readily available in multiple online
libraries. STL files can be sliced using the Freesteel slicer utility found here:
http://www.freesteel.co.uk/wpblog/slicer/. The output image file format recommended is BMP. The output
images should have a 16:10 aspect ratio as output from the slicer, but be resized to 912 × 1140. Resizing
the images will change the aspect ratio, but the diamond array of the DLP4500 DMD will return the image
to the proper 16:10 aspect ratio once projected. Object features should be colored white and the
background should be black. Any white pixels in the object layer images will be printed in the resin.
The object layer images must be isolated in a file directory and stored in alpha-numeric order. Freesteel
slicer will handle this for the user if a static output file name is supplied. No other files should be kept in
the directory with the layer images.
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Introduction to the DLP®3D Printer Reference DesignDLPU025–September 2014
2.1Before using the DLP 3D Printer Reference Design GUI, a few software dependencies and the reference
design software itself, must be installed. The host PC communicates with the DLP 3D Printer controller
through a USB to Serial adaptor by FTDI. The FTDI drivers must be installed before the GUI will run
properly. Please read the following sections for more detailed instructions.
2.2Future Technology Devices International D2XX Driver Installation
The TTL-232R-3V3 device by FTDI allows a USB port on a Windows computer to communicate with TTL
devices. The drivers are not automatically installed by Windows. Follow the procedure below to install the
proper drivers.
1. Go to the FTDI D2XX driver download site, located at http://www.ftdichip.com/Drivers/D2XX.htm and
download the 32-bit Windows, as shown in Figure 2-1.
2. Extract the downloaded .zip file into a convenient folder, as shown in Figure 2-2.
DLPU025–September 2014Installing the DLP®3D Printer Reference Design
Future Technology Devices International D2XX Driver Installation
3. After extraction of the driver files, click the Windows button and open Devices and Printers, as shown
in Figure 2-3.
Figure 2-3. Devices and Printers In The Windows Start Bar
4. Find the device labeled TTL232R-3V3 in the list of devices attached to the computer. Right click the
device, and select Properties, as shown in Figure 2-4.
www.ti.com
Figure 2-4. TTL-232R-3V3 Properties Menu
5. Enter the Hardware tab and click the Properties button, shown in Figure 2-5.
10
Installing the DLP®3D Printer Reference DesignDLPU025–September 2014
Future Technology Devices International D2XX Driver Installation
Figure 2-7. Update Driver Option
8. Click the Browse my computer option, shown in Figure 2-8.
www.ti.com
Figure 2-8. Browse Computer For Driver Files
9. Click the Browse button that is highlighted in Figure 2-9. Select the folder containing the extracted
driver files from step 2, then click the OK button, as shown in Figure 2-9.
12
Installing the DLP®3D Printer Reference DesignDLPU025–September 2014
11. Windows will select the proper drivers from the extracted files and install them. The FTDI D2XX driver
installation is complete. Close all associated windows.
2.3Downloading the DLP 3D Printer Reference Design
Compiled binaries for the DLP 3D Printer Reference Design are offered for convenience if the user does
not want to build them from source. The binaries are distributed along with the source code in a single
executable file which can be downloaded from the Texas Instruments Reference Design site. The source
code and pre-built program are distributed with the TI Design files in a .zip package.
2.4Installing the DLP 3D Printer Reference Design
1. Decompress the "tidc***.zip" file in a convenient location.
2. Install the DLP 3D Printer Reference Design by executing the file "TIDA00293-***-windowsinstaller.exe," as shown in Figure 2-11.
DLPU025–September 2014Installing the DLP®3D Printer Reference Design
5. Select an installation path where the reference design software will be located. Click the Next button,
Installing the DLP 3D Printer Reference Design
Figure 2-13. DLP 3D Printer Reference Design License Agreement Screen
as shown in Figure 2-14. Click the Next button to continue installing the software. Warning: Do not
include any spaces in the installation path for the reference design. Spaces will cause errors if the
software is built from source as described in Chapter 4!
Figure 2-14. DLP 3D Printer Reference Design Installation Path Selection
6. The installer is ready to install, click the Next button to start the process, as shown in Figure 2-15.
DLPU025–September 2014Installing the DLP®3D Printer Reference Design
3.1The DLP 3D Printer Reference Design application allows users to upload images that represent the cross-
sectional layers of a 3-dimensional object. The layers can be generated in a few methods including by
hand, automatically through a CAD utility, or a specific slicing tool designed for cutting a 3-dimensional
model into layers. Freesteel Slicer was used and can be found here:
http://www.freesteel.co.uk/wpblog/slicer/.
3.2Programming The MSTP Cape
This section demonstrates how the DLP 3D Printer firmware is uploaded to the MSP430 on the MSTP
Cape. This method requires an MSP-FET430UIF JTAG debugging tool and Code Composer Studio v4 or
later.
1. Connect the MSP-FET430UIF ribbon cable to J5 of the BeagleBone MSTP cape.
2. Connect the MSP-FET430UIF USB connector to the PC loaded with Code Composer Studio v4 or
later.
3. Run Code Composer Studio.
4. Click the File tab in the menu bar, then click Import... as shown in Figure 3-1.
DLPU025–September 2014Using the DLP®3D Printer Reference Design