Instructables

Rgb matrix, looking for some advice/guidance.?

Hi, its been quite some time since Ive been here. And I still have the same two projects in mind. However, the project im more focused on, is a 32x16 RGB led matrix. Made up of four sections. Im following the project by the two guys over at solderlab.se. They arent very active and speak a different language so their english explanations arent as thorough as Im looking for so I figure id ask the people here :)

So, the main questions I have:
1. What kind of material can I use to put the leds on? its like they use thick cardboard or wood. they drill all four holes per led so the legs go through. I want one big board instead of two. 
2. What spacing would be good to make it look uniform, yet give enough space to solder? 
3. How can I make the 4 controller boards to run it? - They sell them, but they arent cheap. And they dont deliver or sell to the US. So Ill have to make them somehow. I can provide images/part list of what they used. 
4. What type of solder/soldering iron would I need? Obviously various temp. But what temps would be safe? 
5. What power supply can I use?

Ok so, any other info:
-They used common anode LED's 
-They connect the boards together via ethernet cable. 
-They connect the led's together in four sections of 8x16, The anode is connected on each of the 8 rows. And the anodes on all the led's are connected on the 16 rows. If that doesnt make sense, the anodes are connected vertically, and all the cathodes are connected horizontally.
-They connect the 48 cathode wires to ribbon cable, that goes to the controller board, same with the anode wires.  
-They connect the boards to a Usb to UART connector
-Lastly, Part list of one controller board: 
HEXFET IRF7314 x4
TLC5940NT x 3
28 Pin IC-Socket 300mil x 4
Resistor SMD 0,25W 1% 10K x 10
Resistor SMD 0,25W 1% 2K2 x 8
Resistor SMD 0,25W 1% 2K x 3
Resistor SMD 0,25W 1% 220R x 2
Resisitor SMD 0,25W 1% 1K x 3
AtMega 328P x 1
74HC138 SMD x 1
Ceramic Capacitor 22pF, 20% x 2
Oscillator 16,0 MHz x 1
Pinheader 2x8 Pitch 2.54mm x 4
Jumper x 3
Pinheader 1x2 Pitch 2,54mm x 7
Modular Jack x 2
Ceramic Capacitor 100N, 20% x 5
Electrolytic Capacitor 680uF x 1
LED 5mm blue x 1
LED 5mm green x 1
Screw terminal 5.08mm x 1

If theres ANY more info required please ask. It said to be as detailed as possible.

rickharris1 year ago
I am not sure I visualise what your building but I guess it is a large board with a rectangle of LEDs on a 32 x 16 grid.

In the past I have fixed LEDS of many kinds by drilling a suitable sized hole - 5 mm for a 5 mm LED this allows the LED body to be pushed into the hole holding it firmly.

The legs then stick out the back for soldering. I cut then shorter to save having to insulate them.

It depends on what sort of controller you need.

There are many micro processors out there these days PIC up to an old lap top. Some PICs can be programmed in basic if your not into C++ or other more complex languages. You will need to arrange for suitable driver transistors for the LEDs.

A small 25 watt soldering iron should do you fine. As for safety you need to lean to solder quickly and effectively. This only comes with practice.

the LEDS will withstand a reasonable amount of heat or you can use a crocodile clip as a heat sink if you feel nervous.


As for a Power Supply It needs to be big enough to provide the current the LEDS will need.+ 25% in most situations. You will ahve to work out what that means.

Of course it should be a current limited PSU for the LEDS or you will burn them out.

'earl (author)  rickharris1 year ago
Alright, I can add images to better help you get a picture of what Im doing. They sell the boards, however they dont ship to the US. They can be seen here:
http://my.agile-hardware.de/de/leiterplatte-fuer-matrix-controller-boards

They are 11 Euros, And theres a slight chance that when I have the money I can get a friend in the UK to buy 4 of them and ship them to me.

Then I need to get ALL the parts and solder them on. Any good examples of a real good soldering station I could get? I have a small radioshack soldering iron but Ive wanted a station anyway. Im not a PRO at soldering, but Ive made quite a few projects so far.

Im not TOO sure what resistors etc Ill need for the boards, the list is for what they used but I may need some help with the voltages of the LED's I get. Also, they said in most cases a small 5V power supply will work.

as far as a board I think the best option is foam board, and I need to put the pins through only because the way im making the matrix is by putting white ping pong balls over the top of each led, to diffuse the light. However im not sure how sturdy a large piece of foam board is, let alone where to get it.

And im going to add images from a project that will show what I mean.
The first image is a picture of the board with all LED's installed. Not too sure what he used/what its made of.
Second image is a part of the board with one controller on it, so you can see how the led's are connected.
3rd image is 1/4th of the board lit up
4th image is of the front, ping pong balls installed.

Alright. any more questions ask away. And thanks for answering :D
board 1.jpg533277_312458182163774_2080471320_n.jpg1.4th board.jpglight up.jpg