Introduction: BIGLID - Big LED Interactive Display
Step 1: The Minimalistic Design Prototypes
The design was made in a way to fit the plexiglass sheets dimensions, and because they are huge, we had to choose a light aluminum frame to decrease the weight. The interior grid was built out of PVC that is very light.
Step 2: List of Materials and Costs
List of Materials:
- 1 Plexiglass sheet for font panel 2030x1250x3mm - 80 euros
- 1 Sheet of Aluminum/PVC/Aluminum stack ( Debond ) 2030x1250x3mm - 70 euros
- 2 PVC sheet for matrix grid - 3000x2000x3mm - 100 euros
- 1 sheet alveolar poly-carbonate - 30 euros
- 20x40mm aluminum profile - 4 units with 198cm each - 50 euros
- 4 custom metal Corner brackets - 15 euros
- 2065 LED from waterproof APA102 Led strips - 990 euros
- 2 x 5V 350W Power supplies - 60 euros
- 100 units M5 Nuts - 5 euros
- 100 units M5x10 screws - 10 euros
- 20 meters of Wire - 5 euros
- 2 units of USB cables with FTDI chips - 80 euros
- Microsoft Kinect Sensor - 150 euros
Approximate total material costs : 1640 euros
Step 3: List of Tools
List of Tools:
- Hand Drill and 6mm drill bit (for making holes on the plexiglass and aluminum back cover)
- Soldering iron (soldering the led strips)
- Soldering wire
- Hot glue gun (for isolating and gluing the led strips)
- Aluminum profile saw cutter (to cut the aluminum profile rods)
- Screw driver
- Silicone glue
Step 4: The 20x40mm Aluminum Profile Frame
The frame is made out of a rear panel, a front panel and a Aluminum profile frame. The Aluminum profile frame is built out of 20x40mm and 4 custom made corner brackets.
The size of the 2 vertical aluminum profiles are 124cm each.
The size of the 2 horizontal aluminum profiles are 198cm each.
The corner brackets where made form 90 degree bent 300x40x3mm steel.
- Cut the 2 vertical aluminum profile to length using the saw cutter
- Insert nuts on to the aluminum slot profile grooves in order to attach the front and back panel, as well as the corner brackets.
- Screw the corner brackets in place, make sure the screws a tight.
Step 5: The Panel Back Cover
The back panel cover is made from Debond material that is a thin film of aluminum glued on PVC, the actual layout is Aluminum/PVC/Aluminum. The distentions of the sheet used are 125x203cm.
- Cut the sheet according to the dimensions 2030x1250mm
- Make 6mm holes onto the perimeter of the sheet in order to allow rot the screws to pass. These holes will allow the fixation of the sheet to the Aluminum frame profile.
- Keep the protective plastic until end of the build. (this will avoid unnecessary scratches)
Step 6: Attaching the Back Frame to the Aluminum Frame
- Place and align the rear panel on top of the aluminum frame profile, using M5x10 mm screws, screw the panel in place.
- If necessary, loosen the screws from the aluminum corner bracket to allow for any misalignment from the aluminum frame.
Step 7: The White Bottom Layer Martix Sheet
Before the LED strips go inside the housing, a alveolar poly-carbonate sheet has to be marked with a 3.3cm square grid.
- Using a pencil and a ruler mark a 3.3cm square grid onto the 1980x1210cm. This will total 59 columns and 35 rows.
- Leave the top row absent to make space for the cable management.
Step 8: Attaching the LED Strips in a Matrix Configuration
Now with the grid marked on the white panel , we can now glue the led Strips onto the surface.
- Cut 59 strips of 35 LEDs using scissors.
- Position and align the center of the LED's with the center of the marked squares.
- Using a silicone glue, glue the LED's onto the alveolar poly carbonate sheet.
- During the gluing process make sure all LED's are aligned in longitude and latitude in relation to each other.
Step 9: Wiring the LED Strips Into 2 Matrixes
The total matrix is actually divided in 2 matrices one with a total of 29 columns and the other with 30 columns. This was done because in order to achieve a high refresh rate at 30 FPS per matrix, 30 FPS for M1 and 30 FPS for M2.
- The LED Strip has 4 connectors (Ground, 5V, Signal and Clock ), using the diagram with M1 (red) and M2 (green) solder the 4 wires together Signal to Signal, Ground to Ground, 5V to 5V and finally Clock to Clock.
- Make sure to isolate the soldering, we used some hot glue to isolate the soldering parts.
- Keep the wires as short as possible to minimize EMF noise interference and signal attenuation.
Step 10: LED Matrix Cell Divisions
Now that the LEDs are in position, we will need to build a square housing of about 3.3cm height. This was done using huge the 3mm PCV sheets.
- Using a laser cutter cut 58 stripes of 1980x33x3mm and 35 stripes of 1200x33x3mm
- The strips need to be cut in a way thy will attach to each other. You can achieve this by using a CNC or a laser cutter. We did it by hand :) once in a life time experience, never to be repeated :)
- Assemble the grid and position it on top of the LED's, we had to remove the water protection from the LED's in order to minimize back-light bleeding.
Step 11: The Front Panel Plexiglass
The Front plexiglass is light frost color.
- Cut the sheet to size 2030x1250x3mm
- Make 6mm holes on the borders of the sheet in order to allow frame fixation using screws and washers.
- Be careful not to scratch the surface as this will be the front of the screen.
NOTE: We should have gone with a darker color the color we chose is a bit transparent for our taste.
Step 12: 5V Power Supply
The 2065 LED need a lot of power , and that is resolved using 2 - 5V 350W power supplies.The power supplies are wired using common ground, and symmetric color power socket wiring. One of the power supplies powers the M1 Matrix and the second power supply powers the M2 Matrix.
Make sure you use high gauge wire for peak 70A.
The housings for the power supply is located in the back of the Display, we used the leftovers from the Aluminum profile to make the housing. The power supplies are glued onto the back panel of the power supply housing using very strong double sided tape.
Step 13: USB Hi-Speed to UART Cables
The Matrix drives the LED directly form the computer using 2 USB cables. With the following characteristics:
USB FT232H cable Features:
Based on the single chip USB Hi-Speed FT232H device
USB 2.0 Hi-Speed (480 Mbits/second) and Full Speed (12 Mbits/second) compatible
Entire USB protocol handled on the chip – no USB-specific firmware programming required
USB type A connector for direct connection to USB host or hubUSB bus powered
Asynchronous UART transfer data rate up to 12 Mbaud
UART interface support for 7 or 8 data bits, 1 or 2 stop bits and odd / even / mark / space / no parity
Fully assisted hardware or X-On / X-Off software handshaking
Transmit and receive LEDs 1 Kbyte receive and transmit buffers for high data throughput
Adjustable receive buffer timeout
Support for USB suspend and resume
Low operating and USB suspend current
Low USB bandwidth consumption
UHCI / OHCI / EHCI host controller compatible-40°C to +85°C operating temperature range
Cable length is 1.8 m (6 feet)
Step 14: Installing Kinect for Windows Developer Toolkit 1.8
In order to Program the Kinect Sensor you will need to install the Kinect for Windows Developer Toolkit v1.8
Make sure you have the kinect transformer plugged on to the wall socket while operating with the Kinect on a Computer.
Step 15: Installing OPENCV 3.1
OpenCV (Open Source Computer Vision Library) is an open source computer vision and machine learning software library. OpenCV was built to provide a common infrastructure for computer vision applications and to accelerate the use of machine perception in the commercial products. Being a BSD-licensed product, OpenCV makes it easy for businesses to utilize and modify the code. [http://opencv.org/about.html]
Download and install opencv3.1 here:
Step 16: Installing Microsoft Visual Studio 2013
The software for the BigLID was developed using C++ using Visual studio 2013. You can download it here:
Step 17: Programing the LED Matrix
Download The BigLID project folder zip file.
The source file trees is as follows:
BigLID.cpp // main funcion is here
Step 18: Steps for Running the Code
Here are the necessary steps for running the demos you have seen in the video:
1 - Connect The Kinect sensor to the computer
2 - Connect the 2 FT232H USB cables
3 - Turn on the 2 power supplies
4 - Run the BigLID exe file.
The application will start by connecting to the Kinect Sensor and than locate the 2 USB FT232H cables. Once these connection have been established the application will start.