Super Display: An open-source physical display of welcome text in Nigerian languages

Background

The Welcome To Nigeria Challenge was conceived to give Nigeria’s busiest airport a much-needed emotional touch. After the first round, one team was selected by the judges to develop their concept, named Super Display into a full-fledged product. In order to design a physical interface that lists ‘Welcome’ in every Nigerian language, the interface would need to be clearly visible from a distance and may incorporate other signals (such as audio, etc) as it would be displayed in Nigerian international airports or other locations. The product should also have the ability to be updated with new languages.

This documentation provides the instructions for anyone to build a Super Display of their own. It is licensed CC BY-SA 4.0; attribution should be made to the team members as well as Hardware Things.

Team

Table of Contents

1. Bill of Materials
2. Files
3. Build Instructions
   1. Frame Assembly
   2. Display Assembly
   3. Connecting the Electronics
   4. Battery Unit
4. Software Configuration
5. Maintenance
   1. Updating the scrolling text
   2. Changing the graphic display
   3. Battery check
   4. Time and date
   5. Extras
6. Extensions

Bill of Materials

Part No.	Description	Quantity	Buy/Make
WTN-M001	40mm Aluminum Angle bar (1 qt = 18ft)	1.36	Buy
WTN-M002	Fabricated Parts	27	Make (3D Printing)
WTN-M003	Araldite Glue	1	Buy
WTN-M004	Mesh Adhesive Tape	1	Buy
WTN-M005	M2.5 Cross Head 14mm	108	Buy
WTN-M006	M3 Cross Head 8mm	52	Buy
WTN-M007	M4 x32 Anchor Drywall Screw	8	Buy
WTN-M008	M3 Acrylic (Bolt & Nut)	4	Buy
WTN-E001	80mm PWM Fan	2	Buy
WTN-E002	9V 30A SMPS	1	Buy
WTN-E003	P5 RGB matrix display	20	Buy
WTN-E004	Monitoring PCB	1	Fabricate
WTN-E005	300w bulk converter	5	Buy
WTN-E006	18650 battery pack	2	Buy (from local assembler)
WTN-E007	BMS 2S 40A	2	Buy
WTN-E008	5v 2A buck converter	1	Buy
WTN-E009	HD-WF2 Controller	1	Buy
WTN-E010	ESP 32	1	Buy
WTN-E011	DF Mini MP3 Player	1	Buy
WTN-E012	Soldering Lead 60/40 Size	1	Buy
WTN-E013	Complimentary components	sum	Buy
	Pin headers (female and male), Resistors (1k and 10k), Terminal Blocks (2, 6, and 8 pins), Tip 41c transistor.

Files

• Mechanical Design (STEP and Drawings)
• PCB Design (Gerbers)
• Software Assets
• Screen Display (XML)

NOTE: While the product can be built with the PCB file attached above, the current version does not use this. It uses the ESP 32 for its control. We describe how the PCB may be used in the Extensions section.

Build Instructions

Frame Assembly

To make the frame you will need the following aluminium parts (see the mechanical design files), note that the last two are assembly hardware:

Item	Quantity	Dimensions [LxBxH]
S1, S2	1 of each	[324x40x40mm]
T1, T2, T7, T8	1 of each	[802x40x40mm]
T3, T5, T4, T8	1 of each	[800x40x40mm]
J1, J2, J3, J4	1 of each	[40x40x40mm]
Internal Rail	18	[160x20x20mm]
Brace (M1)	3	[324x40x3mm]
LINK	6	[40x22.5x40mm]
M2.5 Cross Head 14mm	108	see BOM
M3 Cross Head 8mm	52	see BOM

Use LINK to fasten T3 to T1, then T5 to T3, then T7 to T5, then T4 to T2, then T6 to T4, and T8 to T6. See Figures 3 and 4 for layout.

Next, Use J1 to fasten S1 to T1, then use J2 to fasten S1 & T2, then use J3 to fasten T7 to S2, then use J4 to fasten T8 to S2, and use M1 to brace T3, T5, T4, & T6 together. See Figure 5 for the layout and Figures 6 and 7 for the assembly process.

NOTES:

1. Fabrication of the display frame will require 24.41ft of 40mm Aluminum angle.
2. Holes in some 3D printed parts may not fit accurately. Print without holes, drill after.
3. The Aluminum angles available locally are in several colloquially named variants. Use parts with 2mm thickness (see Figure 8 below). Thicker ones are heavier, and may overload the mount.

   

Display Assembly

Assembling the display requires 9 bulk to display mounts. Each mount requires three 3D printed parts (see Mechanical Design files for this) as shown below. 2 DP1 parts are requires, while 1 DP2 part is also required.

To assemble one bulk to display mount, join two DP1 parts together and then fit DP2 on, as shown below in Figure 10.

After that, use the assembled mount pieces to fasten the P5 Matrix LED panels together as shown in the Figure 11 animation.

Connecting the Electronics

To make the battery pack you will need the following parts:

Item	Quantity
P5 LED matrix display	20
300w bulk converter	5
4mm wire cable	5 yards

Take the following steps:

1. Mount all the display to the frame while making sure all arrows are pointing in the same direction.
2. Connect the displays on the same row with hub75 connector (white cable).
3. Connect WF2 controller to the first led matrix.
4. Connect each bulk converter to the charger and turn the potentiometer till the output voltage is 5V.
5. Connect 4 led matrix to one 300W bulk converter.
6. Connect the 9V 30A charger to mains power supply.
7. Connect the batteries to the charger.
8. Connect the charger to each bulk convert input port with the 4mm cable(blue and yellow cable).
9. Connect the WF2 controller to one of the bulk converter’s outputs for power.

Figure 12 also shows the electronic connection when completed.

Battery Unit

The battery is made of 96 2200mAh 18650 lithium ion cells made into two battery packs (48 cells each) 6 by 8 configuration. Each battery pack is connected to 40 Amps 2s BMS. The battery packs are charged with a 9V 30 Amps power supply. To make the battery pack you need the following:

Item	Quantity
18650 2200mAh lithium ion cells	96
18650 combination bracket	96
0.15x8mm nickel strip	10 meters
Insulating pad
Spot welder
40A 2s BMS	2
4mm wire cable

Take the following steps to make the battery pack:

1. Interlock the 18650 combination bracket to form two 6 by 8 boxes.

2. Arrange 48 cells on each box as shown below.

3. Connect the battery together (2s 24p) with the spot welder and the nickel stripe (see Figure 14).

   

4. Connect the battery packs to the bms according to the diagram below.

   

   
   

5. Cut the insulating pad and attach to the battery packs top and bottom.

Software Configuration

The HD 2020 software (see tutorial for more guidance) is used to design and program the screen display. The software has many features which enable graphics, animated characters, time and date settings, countdowns, U disk export and more.

New display and program files (first level content)

Method: Click File -> New Display, and the setting dialog box pops up.

The control card already has the correct parameters (normal display text), create a new display screen, click OK, and complete the establishment of a display screen and a program. If the control card does not have the correct parameters (i.e., the text is not displayed normally), select the device, select the color, set the width, height, and gray level; then click to enter the hardware setting interface and set the display point method of the display, that is, commonly used smart settings such as: network cable, serial cable, or Wi-Fi for intelligent settings. Wi-Fi was used for Super Display.

Create a new partition (second-level content, each program can be set up with 20 partitions)

Method: After selecting the program, click on the graphic, text, time, timing, counting, temperature and humidity, animated characters, Chinese calendar, etc. to create different types of partitions.

Communication settings (Wi-Fi card)

When the Wi-Fi card is connected, first connect the Wi-Fi signal sent by the control card (requires a computer with a wireless network card, if using a desktop computer, be sure to purchase a wireless network card; generally a laptop with a wireless network card is preferred).

When connecting to a Wi-Fi signal, the default password is “88888888”. If you connect with the HD 2020 software, you need to enter the password of “88888888”, Click Connect, and the default password can also be modified. Once Wi-Fi is connected, the device can be found in the software. The information window will appear on the online bar of the control card and other information.

Maintenance

Updating the scrolling text

The text can be updated via wifi (mobile or PC) or physical flash drive. The app required for the mobile control is called LedArt, this application has the ability to switch programs, change text, increase and decrease brightness of the super display wirelessly. The app required for PC control is the HD2020, the app gives the user the ability to fully control the display both wirelessly and through a flashdrive.

Changing the text and graphic display

For text-only content display, we use text areas to meet the requirements. The text supports left rotation, right rotation, and reverse. The table was customized, borders, and background were added.

The steps to change the text are:

• Create a display screen.
• Click the text, the text area appears (coordinates, width, and height can be set freely).

To change the language:

• Click the text area.
• Add language text.

To change the graphics on the display the new design can be uploaded wirelessly or via usb through the PC application. There was an instance where we wanted to display pictures instead of text. We took the following steps:

• Create a display screen.
• Click the picture and text, the picture and text area (coordinates, width, and height can be set freely), add the picture to be displayed in the blue icon (see Figure 21).
• Graphics were made by third party apps, like Corel Draw and Photoshop.

Battery check

A custom PCB extension is available to wirelessly monitor the battery voltage and current consumption in real time. The board has 5 voltage sensors (voltage divider) that measures the voltage at each bulk converter and the battery and displayed on a localhost web server, the pcb is controlled by an ESP 32 microcontroller. To access the webserver connect the ESP 32 to your computer and open a serial port, copy the link and paste in your browser to view the life data.

Time and date

The LED controller used is the WF2 LED controller which has the ability to display current time and date (CMOS) and this can be included in programs sent via the mobile or PC application. The time display on the display is similar to text and graphics. The steps are as follows:

• Create a display screen.
• Click the time, the time zone appears, the setting is relatively simple, and the location can be set, as shown in the Figure TK.

Extras

1. Time setting: Set the time on the control card, which can be the current time of the system, or it can be the elapsed or future time.
2. Brightness setting: divided into manual, automatic adjustment (requires additional sensor), three types of adjustment by time.
3. Timer power on / off: Set the startup time and shutdown time of the control card.
4. Startup screen: Enable the startup screen, click OK after loading the file, or export the file to a USB flash drive.
5. Firmware update: used to upgrade the control card.
6. Power-on prompt: Used to remove the power-on prompt of the control card, you can set not to display / show all / firmware version / control card & memory size.
7. Screen control: used to control the on / off / play / pause of the display.

Extensions

Electronics

An extension for the super display includes 5 voltage sensors to measure the voltage at bulk converters, current sensor to measure the display’s total current consumption, a PIR sensor to measure human proximity, an mp3 module and a speaker to send a verbal message, a temperature sensor to measure the device temperature and a 4 DC fans for cooling. The entire board is powered by an esp32 microcontroller and all measured data is displayed on a localhost webpage.

Mechanical

To use the electronic extension above, you’d need the elec. to disp. mount (see Mechanical Design files). Each mount requires three 3D printed parts.