Unboxing TI’s DLP LightCrafter
Together with his engineering team, Kuten has studied the pico projector (DLP3000-C300REF) offered by Texas Instruments.
They came up with an analysis of the supplied package, its circuitry, the startup demo, and now they share their first impressions with photos and screenshots of the different operational modes, together with a software assembly description (Linux + rootfs) and their own evaluation.
Read Kuten’s unboxing report below:
There are a number of technologies employed in modern pico projectors: DLP (Digital Light Processing); LCoS (Liquid crystal on silicon) and LCD. We will not discuss the last two, but will dwell in greater detail on DLP, which is the technology our device uses.
DLP is based on DMD, digital micromirror device, a chipset, which has on its surface several hundred thousand micromirrors put together in a single pixel array.
Each of the mirrors can deflect in both directions from its initial position at a slight angle (10-12 degrees), which enables ONOFF. Light hitting the mirror will be directed to the optics or sideways (usually to the cooling system). To display halftones, the mirror goes from “on” to “off” at high speed, using pulse width modulation.
Red, green and blue LEDs are used as emitters.
Package contents
The device itself was located in a small box. There were no cables and software. All things had to be supplied individually, but it is no problem if you have the Internet and standard cables.
The package had the following contents:
Trigger Input/Output
Mini USB
Power Connector
Mini HDMI
UART
Power Socket
I2C
FPGA SPI Flash Programming Interface
MSP430/DLPC300 Flash Programming Interface
On/Off Button
Input Selection Button (DM365/Internal Test Pattern/HDMI input)
Ethernet PHY
Fan
Camera
Focus Control
Boot Mode Selection Switch
Micro SD card
DLP LightCrafter (DLP3000-C300REF) Reference Design: Technical Features
RGB LED light engine with 20L light output.
High speed patterns using the native DLP3000 resolution (608×684).
Up to 4000 Hz binary pattern rate.
Up to 120 Hz 8-bit grayscale pattern rate.
Display images or video up to WVGA resolution (854 x 480).
Configurable I/O trigger for synchronizing with cameras, sensors, etc.
DM365 embedded processor running embedded Linux.
128MB NAND flash memory for pattern and sequence storage.
USB, Mini HDMI, UART interfaces.
USB-based API and host GUI.
Compact size: 117mm x 65mm x 23mm.
The device is a “sandwich” of two boards on a metal base. Next to it, there is an optical module with an emitter connected to the boards with flexible cables. The metal base also serves as a heat sink. The product’s structure is reliable and practical. All the necessary connectors are located along the perimeter and on top. Basically, it is the way it should be for devices like this.
Circuitry
The EVM module includes a CPU board, a driver board and a light emitter. DM365 is the multimedia processor TMS320DM365 based on the DaVinci technology by Texas Instruments. It is used for launching Embedded Linux. FPGA is Altera Cyclone IV FPGA; it controls the mixing of video channels (HDMI or DM365), the switching of LEDs and internal buffers for fast display of patterns. DLPC300 is a DMD controller. MSP430 controls power and LED drivers.
Connection
Power can be supplied directly to the computer USB (preferably from a separate power supply) through connection to the jack on the DC_IN lower board.
The debug UART is connected to Minijack 2.5, but, for the lack of it, we just soldered in to it (red wires in the yellow cambric). MiniUSB is a standard cable. HDMI through MiniHDMI/HDMI.
Bring up
Texas Instruments provides a cross-platform graphic EVM utility, which displays images and video from a camera / HDMI, as well as helps update embedded software.
There is also an example of a command line provided by API.
Operational modes
Internal patterns:
Static image:
HDMI video:
Software assembly (Linux + rootfs) for Micro SD boot
The manufacturer has taken care of trouble-free assembly and software startup for your device. It offers a good BSP, which helps obtain workable binary images in a short time.
First you have to download and install Linux DVSDK using the following link. It must be version 4.02 which is equipped DM365 support. The manuals say that the host must necessarily be ubuntu 10.04. But we still had trouble transferring the installed SDK to ubuntu 12.04.
Next, under the link, we should find DLP LightCrafter DM365 DVSDK (version 4.0), download and install it. Out of the Changes subfolder with installed files, you have to copy and replace the files with the previously installed Linux DVSDK files.
The assembly is performed with the Sourcery toolchain for ARM by Mentor Graphics. You can download and install it by clicking the link. It is important to remember to add to the $PATH description the path to the toolchain prefix.
The assembly is done in steps using the commands make, make all and make components. U-boot, uImage and rootfs images are created to be used with a SD card.
To install all this on an SD card, you can use the ready-to-use script, mksdboot_lcr.sh, located in the bin folder.
After the completion of the script, you have to insert the card into the connector and move the switch closer to the connector.
The loading takes some more time.
Conclusions
A new platform for developing Texas Instruments pico projectors under the LightCrafter brand use a digital light processor (DLP) based on the МЕМС technology with almost half a million of micromirrors to generate an image. RGB LEDs are used as a light source which can emit up to 20 lumen of light. However, if you use active cooling and thermal management, you can obtain over 50 lumens, so you can use LightCrafter in various conditions.
DLP LightCrafter can be employed as a portable projector with an HDMI input, as well as a platform for projecting structured light patterns and complex lighting with the possibility of changing the operating wavelength (from ultraviolet to almost infrared light).
The option of projecting structured light patterns makes it possible to use LightCrafter for instant characterization and recognition of 3D objects without touching them. 3D scanning is based on projecting a moving strip of light to the objects, as well as subsequent analysis of measurement of the deformation of the reflected band using a 3D shape reconstruction algorithm.
This function can be used in contactless fingerprint scanners to identify people. Besides its use for biometric, facial, dental and medical scans, DLP can be used in various applications ranging from industrial control systems to a variety of scientific instruments. By using additional FPGA, you can increase the frequency of outputting light patterns up to 4,000 per second.
3D scanning implementation needs an external camera and software that implements the required 3D processing algorithm. The configurable platform gate input / output helps synchronize camera frame capture (for the camera and other peripherals) with projected light pattern frames.
Developers can create, store and display the projected image using a programming interface (API) via USB or a user-friendly graphical user interface (GUI).
The powerful digital processor TMS320DM365 and ARM core-based Linux make it possible to develop a fully functional embedded system. Therefore, the use of DLP LightCrafter in new developments helps cut the design cycle, as well as achieve a small form factor and a low cost of the final product.
Visit Promwad at www.promwad.com
About the author:
Ivan Kuten is a technical expert at Promwad Innovation Company (Minsk / Moscow), an independent electronics design house in Eastern Europe – www.promwad.com – You can reach him at info@promwad.com
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