8 MAX72XX is the limit

I reached the limit on how many MAX7219's can be chained together. That's 8. Good article here, so I'll have to use another 3 outputs on the arduino for my 5th matrix. Photos soon.

External Power

So I did some reading and some internet searching, and think I have at least part of the power issue figured out. I purchased a 7805 +5VDC Voltage Regulator, wired up my 1/2 size breadboard as my external power supply and added an led to that board and to 3 others down the line as a visual to see if power is being routed properly. Now with just the ground from the Arduino going into the circuit I can get everything operating properly. So the next test will be to get a Voltage Regulator with a higher current rating and a heat sink to get up to the current I need to drive all of the leds. 2 internet posts that helped a bunch. *ITP Physical Computing & *http://pixelriot.com/pmatp/node/285

Also http://www.tkk.fi/Misc/Electronics/circuits/psu_5v.html

4 and counting

We're up to 4 8x8 2 color matrixes. Hopefully move to 5 tomorrow. Then it's time to really start focusing on the power supply.

Wiring things properly helps

So my knowledge of how breadboards work or lack there-of may of been stopping me from adding more matrixes to my test system. I now have 3 working, although one only can show green as I'm waiting for more Max7219s. They should be here tomorrow, so hopefully I can get 5 (the amount I've purchased so far) matrixes up and running. I still need to figure out the solar system for the 3 signs on hill and how to add extra power after the arduino runs of of forward current to drive the matrixes. Hopefully I can find that threshold.

If anyone out there in internet land can help me with these calculations I would be greatly appreciatative. Here are the datasheets for all of the parts. AT Mega 328(Arduino), XBee, 8x8 Led, Max 7219.

Cutting the cord

Well one of them. We're now offcially wireless. I got 2 xbees talking to each other and was able to move my 2 matrixes across the room. This article here helped a lot with setting up the xbees. Next step will be power. Preferably we'd run on solar power (I can get one matrix running & xbee if I plug straight into the solar panel) still working on wiring up the battery and running off of that.

Of note I didn't have to change my arduino code at all, just plugged one xbee straight into the iobridge, GND->GND, 5V->5V, Rx->Tx & Tx ->Rx. The other xbee went to the arduino, 3.3v ->3v, GND->GND, Rx ->Tx & Tx ->Rx. Simple as that. Photos shortly, gotta charge my camera.