I have a LED Matrix just like this one

but couldn't find the data sheet for it (1855AS) I asked around in my country and one guy told me to try attaching one side to 5v and the other to GND. Some LEDs worked fine and others didn't light up at all. In the end one if not more got burned.

So I'm here asking if anyone can tell me a way to figure out how it works. I would appreciate the help!

  • BTW I don't have an Avometer!
    – ArwaSh
    Apr 2, 2015 at 23:14
  • I think all those 8x8 matrixes are pretty much the same. Here is some datasheet. I wouldn't be surprised if the pinouts are exactly the same. See bottom of page 3, for how these displays are wired inside. Also, you definitely need to use resistors, or the leds will burn out.
    – Gerben
    Apr 3, 2015 at 12:34
  • That's what they told me! But I don't think this one is. Would 220ohm resistors be enough ?
    – ArwaSh
    Apr 3, 2015 at 12:48
  • 220 is a very nice value.
    – Gerben
    Apr 3, 2015 at 12:50

2 Answers 2


As you are testing the correct functionality of LEDs on matrix board, which means the LEDs are multiplexed together. The fastest way to check the pinout is to use a multimeter in continuity test mode and then connect the positive or signal wire ( the red one ) to an fixed pin (usually start with one ) and the with negative or gnd wire ( the black one ) connect it one by one to the all the remaining pins. When you have finished move the signal wire to the next pin and rescan all the pins, repeat all the steps for every pins on the matrix board. I don't recommend you to use directly 5v because it can be dangerous and you can damage the LEDs of the matrix display as there isn't a current limiting resistor.

  • Would it be ok if I used 3.3v and/or a 220ohm resistor and check each pin ? I don't have a multimeter at the moment. And thanks for your help!
    – ArwaSh
    Apr 3, 2015 at 12:43
  • I suggest you to use 3v3 with 220ohm resistor in series.. That will be OK.
    – Harry
    Apr 3, 2015 at 19:01

You could check from where you have bought it. Maybe they have datasheet. I found one similar, but before you must check if everything is the same and then do testing with power. LuckyLight

  • That might take a while, It's a bit far from where I live. And I don't think they'd be helpful.
    – ArwaSh
    Apr 3, 2015 at 12:46
  • What do you mean by that???
    – Martynas
    Apr 3, 2015 at 20:12
  • I mean the shop I got this matrix from is far from where I live and the people who work there won't be very helpful because everyone around here acts like they know everything which they don't. I said I asked around right? And just like that two got in a fight each one of them says he's better than the other. And thanks to them some LEDs got burned from the matrix! I'm sorry for speaking like this .. and thanks for your help ! :)
    – ArwaSh
    Apr 3, 2015 at 20:26
  • Dude... I gave you datasheet. Conect some resistors like 1k ohm and then test. You do not need to ask someone;)
    – Martynas
    Apr 4, 2015 at 15:53
  • With 1k resistor it will shine not so bright but you wont damage leds...
    – Martynas
    Apr 4, 2015 at 15:57

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