I have a new mega board that arrived in the mail to day. along with a big box of simple standard LED lights.
Link corrected. I bought a pack of those for my granddaughter, but don't expect her to make use of them easily. I figure you will be mightily challenged too!
with my new knowledge of Arduino I'm hoping to finally surpass the neighbors display this year. hehe
Maybe, but don't bet on it if their name is Holdman!
i would like to wire an 8 by 8 matrix of LEDs. this would give me 64 individually controlled "points" i can control with my board.
But not direcly.
then i would intend to connect several LEDs in parallel to each individually controlled "point" on the matrix grid.
Not a good idea!
I have wired small LED matrixs before and i am familiar with the necessary programming. My electronics knowledge is far behind my programming knowledge.
OK. If you were wiring them directly to the Arduino, then you have big problems.
If i bypass my mega's voltage regulator and supply 5 volts to its five volts pin with a big regulated power source, is there still a limit to how many LEDs I can power with the pins?
There sure is! You should never be using the on-board voltage regulator anyway if you want to connect stuff to the Arduino. It is OK to power the microcontroller itself and maybe half a dozen LEDs at less than 20 mA each.
aside from the basic matrix wiring pattern i have no clue what kind of kind of circuit i would need if a couple hundred or so LEDs surpass the power limits of the board.
I suggest making up your matrices of exactly 8 by 8 LEDs each and just buy three, four, five or whatever of these kits:
Or these ones
which used to be more expensive but are now actually cheaper and more useful if you wish to stack matrix arrays.
The point is that you do not install the matrix arrays from the kits themselves - or their socket pins, but just solder to the positions on the PCB and you have a durable and reliable assembly to drive your own matrix arrays.
Why did I say three, four or five? Well, you can fully assemble the first one as the matrix with which it comes and practice programming it. Then the others for your current project and maybe some for the next!
would the power consumption be a problem?
Not if you have a decent 5 V supply. Everything runs from 5 V, not some other. (These MAX7219 matrices draw 320 mA each.)
would i need some sort of resistors in my curcut? where would I put them?
These modules include one current programming resistor. The MAX7219 does the rest. Don't even dream of driving them directly from your Arduino and the Mega is useless unless you have some really complex code and need its extra storage beyond a Nano.
Frankly, the only use I can think of for a Mega is with a larger graphic display that requires lots of pins and lots of code.