Mithotronic

Home of the LEDmePlay. Since 2013.

LEDmePlay



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Introduction

The following sections describe how to build the LEDmePlay with the appearance shown on this site. Feel free to change parts of our design or add extra features, such as additional buttons, a more fancy housing, a smaller LED matrix. Before you start with the reproduction of the LEDmePlay, you need to buy the required electronics parts. The main components are the Arduino Mega 2560, the RGB LED matrix, and a suitable power supply. Additionally, you need some cables to connect everything. Whether you plan to use the same picture frames that we used for the housing is up to you. The joysticks need not be the same as ours. Any C64 compatible joysticks from the Eighties era should work. What about real arcade controllers inside a small arcade cabinet? Here is the parts list. Unless otherwise stated, you can buy these or compatible parts from any electronics specialist shop. We paid an overall price of approximately 120 EUR.

Main components

Arduino Mega 2560
RGB LED matrix 32 * 32, e.g., from Adafruit (www.adafruit.com, PRODUCT ID: 1484) or a compatible matrix with pixel configuration SMD3528 1R1G1B (P6 with the size 192mm * 192mm)
2 * C64/AMIGA-Joysticks (e.g., Competition Pro, Quickjoy, Quickshot)
switching power supply (5V, 4A) with overload protection (In general 2A should be enough, since the 4A are only required if you set all LEDs to white with highest intensity.)


Connections and buttons

potentiometer 4.7KΩ (for volume control)
2 push buttons (reset, pause)
switch (on/off)
2 * 9-pole sub-D male connector (joysticks)
5.5mm female connector (connection to power supply)
5.5mm male connector (internal connection to Arduino)
small speaker (e.g. LSM-50A-8 with 8Ω)
(optional) USB female connector (hexagonal, not the flat type) (connection to computer)
(optional) USB male connector (internal connection to Arduino)


Cable and other small parts

copper strand (for internal connections)
ribbon cable (16-pole)
female connector (multi-contact IDC connector) for ribbon cable
multi-pin connector grid dimension 2.54mm (male)
heat shrink tube
4 * distance sleeve
M3 screws (short ones and a few long ones for the Arduino board)
M3 nuts
M3 snap rings


Housing

2 * picture frames model of size 252mm * 252mm * 45mm (from a Swedish home-center)
small woodscrews
Self adhesive protectors as bases


Overview of all parts before starting with the construction:

LEDmePlay


Preparing the Arduino

Before you start with the construction, we recommend to install the Arduino software on your computer. You will need it to flash the Arduino board with our games and of course if you want to develop your own games. Please check the Arduino homepage where you can find all required information on installation and uploading software (http://www.arduino.org or http://www.arduino.cc). Furthermore, you need libraries for the RGB matrix. These are available on the Adafruit web site. Please check http://learn.adafruit.com/32x16-32x32-rgb-led-matrix/downloads. You need the AdafruitGFXLibraryMaster and the RGBMatrixPanelMaster library which must be copied to your Arduino directory on your computer. The path could be C:\Program Files (x86)\Arduino\libraries. After that it is useful to flash the Arduino with one of the example programs. For instance, try the demo named plasma_32x32 from RGBMatrixPanel directory. The result is simply beautiful. As we use the Arduino Mega 2560 we need to adapt the code of the demo a bit since the original code is for the Arduino UNO board (which uses a different pin assignment). Replace the following lines

#define CLK 8 // MUST be on PORTB!
#define OE 9


by these lines:

#define CLK 50
#define OE 51


After that the program can be uploaded to the Arduino Mega board and you are ready for the later test.

Connect the Arduino Mega with the RGB LED matrix and the power supply

We will now make the connections between the Arduino and the RGB LED matrix. Prior to that you might have to link the two parts of the matrix by power lines which depends on your variant of the matrix. There are different variants in the field like the one shown here on the pictures. If you have this variant, you should have the power lines in the same package as the matrix itself. The upper pins, that correspond to the positive pole, are connected to the red cable as depicted on the right-hand picture. For the alternative variant, this is not required.

Arduino and RGB LED matrix


Rear view of the matrix



We now need to solder the connection cable. Plug the 16-pole ribbon cable into the female connector on the one side (by compressing the clips of the connector) (cf. picture below on the left-hand side). This end is connected with the matrix. The other end of the cable requires some more work. First, you have to strip the cables. Then you have to solder male pin connectors which are plugged into the Arduino.

Ribbon cable with female connector


Ribbon cable with male pin connectors



For the connection, the scheme below is required. Cut the multipin connectors into the required sizes (you will need 4 times length 2, length 4, and a single pin). Please use the heat shrink tube before you solder the pins to the cables. After solding, you can heat them e.g., with a hairdryer. See the finished cable end on the picture above on the right-hand side. Note according to the connection scheme below: Some Arduino boards have a misleading pin labeling. Pin 24 and 25 are in the third row of the double-row connector on the right-hand side. The 2*2 pins above remain unused.

Connections between the LED matrix and the Arduino Mega

Pole 1: R1 digital 24 (1st pin of the 1st length 2 multipin connector)
Pole 2: G1 digital 25 (2nd pin of the 1st length 2 multipin connector)
Pole 3: B1 digital 26 (1st pin of the 2nd length 2 multipin connector)
Pole 4: GND not used
Pole 5: R2 digital 27 (2nd pin of the 2nd length 2 multipin connector)
Pole 6: G2 digital 28 (1st pin of the 3rd length 2 multipin connector)
Pole 7: B2 digital 29 (2nd pin of the 3rd length 2 multipin connector)
Pole 8: GND not used
Pole 9: A analog 0 (1st pin of the length 4 multipin connector)
Pole 10: B analog 1 (2nd pin of the length 4 multipin connector)
Pole 11: C analog 2 (3rd pin of the length 4 multipin connector)
Pole 12: D analog 3 (4th pin of the length 4 multipin connector)
Pole 13: CLK digital 50 (1st pin of the 4th length 2 multipin connector)
Pole 14: LAT (STB) digital 10 (single pin)
Pole 15: OE digital 51 (2nd pin of the 4th length 2 multipin connector)
Pole 16: GND not used


Next is the Y-cable from the power supply to the Arduino and the LED matrix (cf. left-hand picture). You need a female connector that fits your power supply. Before you start soldering, consider the polarity. The thick red cable on the matrix shall connect the positive poles. The Arduino is connected via another male connector that fits into the power jack. Note that the inner pin of the Arduino jack demands the positive pole. Optionally, you can install an on/off switch between the female connector and the power cables that lead to LED matrix and Arduino. Now we are ready for the first test. Make sure that your power adapter is set to 5V and that the polarity is correct. Connect the ribbon cable to the matrix and to the Arduino pins as described above. Then power the matrix and the Arduino with your newly created power cable (cf. right-hand picture).

Power adapter


Preparation for the first test



Ensure that everything has been wired correctly, then switch on the power. After a few seconds the Arduino should start to execute the program. You should see something on the RGB LED matrix. Congratulations - this was the most challenging part!

LEDmePlay



Soldering the remaining connectors

Our games support standard C64/AMIGA joysticks with one fire button. For this, you need 9-pole sub-D male connectors. The 9-pole connectors need to be soldered to 6-pin male multipin connectors that lead to the Arduino (please see the pin assignment below for the two joysticks). Furthermore, you need to connect the reset and the pause push buttons. The audio pin is soldered directly to the speaker. Looping-in the potentiometer in-between makes the volume adjustable. Please note that you need to link several wires to the Arduino's ground pin (GND): the other pin of the speaker, the second pins of the push buttons and the pin 8 of the sub-D connectors. The following overview shows the pin assignment for the joysticks, the buttons and the speaker.

Other connections

audiopin digital 2 (connected with the potentiometer)
joystick 1 up: sub-D male pin 1 digital 30
joystick 1 down: sub-D male pin 2 digital 32
joystick 1 left: sub-D male pin 3 digital 34
joystick 1 right: sub-D male pin 4 digital 36
joystick 1 fire: sub-D male pin 6 digital 38
Joystick 1: sub-D male pin 8 GND
joystick 1 fire 2 (optional): sub-D male pin 9 digital 40
joystick 2 up: sub-D male pin 1 digital 31
joystick 2 down: sub-D male pin 2 digital 33
joystick 2 left: sub-D male pin 3 digital 35
joystick 2 right: sub-D male pin 4 digital 37
joystick 2 fire: sub-D male pin 6 digital 39
Joystick 2: sub-D male pin 8 GND
joystick 2 fire 2 (optional): sub-D male pin 9 digital 41
reset push button digital 42
pause push button digital 43


The pictures below help to assign the pins of the sub-D mal connector. Pin 5 is never used. Pin 9, which is optional, is, as well, not used on the picture. After soldering you are ready to play. Please check our games section.

sub-D male soldered cables


sub-D male ordering of soldering tags



Housing

If everything was successful, you can construct a housing. Thereby, the possibilities are endless. We use two picture frames available at a Swedish home-center which are screwed together. The first one contains only the LED matrix which is fixed to the rear panel. That one must be tooled with a saw before, in order to have a rectangular hole for the cables (cf. left-hand picture below). The glass pane of the second frame is removed. The two frames are screwed together at their inner sides using small metal or wooden plates. These are held in place by wood screws (cf. middle of right-hand picture below). The rear panel of the second frame carries the Arduino micro controller board, the speaker, and the connectors. The rear panel can be kept in place by the clamps of the frame when closed. The easiest way to maintain a USB connection to your computer would be to saw a small opening into the rear panel as a cable outlet. There you can plug an extension cable if required. If you have another idea for a housing, please let us know.

Prepared for the first test


Screwed frames


LEDmePlay


Rear view