Common cathode or anode?
Brightness? (mcd/color)
Forward Voltage?
Resistors included in circuit?
What kind of connection output does it have? (pin header, ribbon cable, etc)
Are the LEDs diffused?
We would release an Arduino like board for directly control of these dot matrix, it will include various interfaces for casacading, adjusted circuit, and library ready to go. seeedstudio.com/blog/?page_id=187
Well, I got the RGB matrix (#220324377200) and I have an Arduino Duemilanove and I have some 74hc595 chips. My problem is I have no idea what each of the pins on the matrix are for. I have looked at the data sheet. Perhaps a more experienced person could figure this out at a glance, but I’m sorta new to this. Is there a schematic somewhere that I have missed? I would guess that 8 on each side are used to address the cells, but what are the other 8 for?
Thanks for that. I’m looking at it now and trying to figure out how to use this with a Mega. This schematic is just for a “raw” mega168 board yeah? Not necessarily the arduino?
it should be near the same thing. you just have to be mindful of the inputs that the schematic is using, then make sure your using the right ones in your code.
What’s important for you is the right part of the schematic.
The shift register’s serial input (SER) is wired to the arduino’s MOSI line, clock (SRCLK) is wired to the arduino’s SCK line, the latch (RCLK) is wired to the arduino’s SS line, display enable (G) is wired to a digital output of the arduino board. In my code I used pin 9.
MOSI: duemlanove: 11 / MEGA: 51
SCK: duemilanove: 13 / MEGA: 52
SS : duemilanove: 10 / MEGA: 53
enable: duemilanove: 9 / MEGA: (use any digital output line + change the #define in the code)
The code compiles on 168/328/1280 chips without modifications for register names. As I don’t have a MEGA board I can’t test though.
Don’t forget to use a 10k pullup for the (G) line, this keeps the LEDs off if you upload new code. Also wire the (SRCLR) line to +5V. That line is active-low and clears the data, which you don’t want
Thanks for taking the time to post all of this. I actually purchased 4 of these so will be 16 X 16. As soon as I get the 8 x 8 controllable.
Also I’m trying to make an Adobe Air app to produce the animations to make it easy. I’ll try to make it as “dynamic” as possible to to maximize it’s usefulness. Unless somebody knows of something already out there?
Thanks for all the great info, especially the tutorial at instructables.com. I now realize that I should have posted a link to your blog and not directly to the schematic.
I got together 16 74hc595 shift registers to power my 4 8x8 matrix’s. But now I’m wondering how I can push enough current to power all 768 LEDs ((16x16)x3(RGB).
I found a post on instructables where they mentioned using this part instead:
whats the need to power them all at once? you could simulate that by just cycling through them faster than the eye can notice. that way you can stay under the large power requirements and not have to have extra hardware to turn them all on at once.