Hi, does anyone have a small howto on how to connect the matrix to the Arduino? I think i could read from the libraries that not much is needed.. but i fail with power and such stuff.. any ideas?
Look up matrix here:- http://www.arduino.cc/playground/Main/InterfacingWithHardware
thanks for the reply but i already know that page and it is basically good yet doesnt say anything about wiring up the 2416....
Well Florin uses them in his wise clock 2: http://www.timewitharduino.blogspot.com You could contact him and see if there is any basic code he can link you to/send you.
Apart from that, there are examples for the 0832 LED matrix which is where I think Florin got the basics of the code. I thought there was a page on the 2416 but I can't find it.
THanks. Basically i think i could read from the libs how to connect it.. but one thing is strange.. the Arduino 'turns off' when i connect the display, much as if i would shorten 5V and GND though the Power LED just fades away.. i have nothing else connected and in the paper it says it would take 250ma at maximum.. so.. any suggestionss about that?
Check between the gnd and 5v pins with a multimeter and see what resistance you get. If none at all then you might want to check for shorts along all of those lines.
I got resistance there.. so shorts are a no go i think...?
Hmm. Have you tried powering the matrix from an external 5v power supply? As in not through the arduino regulator.
since i lack one i havent tried.. what i did try was using external power on the arduino with about 1A and then feeding the matrix though the 5V line (which should have then more than 500ma, right?)
and then feeding the matrix though the 5V line (which should have then more than 500ma, right?)
No, the arduino regulator can only supply 400mA and the ATmega chip needs some of that (about 5-10mA i think) so if the 2416 needs 500mA then you will need to use an external power supply.
I think that would make sense of the low brightness LED on the arduino as the matrix would steal all the power.
Doesent the voltage regulator on Arduino do a thermal shutdown if it gets too hot (= too much current passing through it) ?
I seem to remember that without heatsinking you can draw only somewhere between 200 and 300 mA.
Hmm, yeah but it obviously depends on the input voltage. At the minimum voltage of about 7V (due to minimum on the regulator and the diode drop) then I would have thought you can probably draw almost the full current without it overheating.
I think the next step is still to try powering it independently with a 5V power supply.
the Arduino 'turns off' when i connect the display
It may reset itself for some reason. I would try decoupling with capacitors (100nF + 100 microF).
I've used the 2416 display both with USB power and with external power to the display. It's brighter with external display power, but it should be fully functional with just USB power to the Arduino. (Assuming you don't have other hardware connected to the Arduino).
You should have 3 digital pins, 5V, and ground connected to the display.
There is a "Chip Select" dip switch on the display that must be set to match the chip select pin you connect to. But you probably knew that.
Strange... I just got my external 5V (1000ma) power and connected it to the display - following configuration:
Pin (Display) 1 to CD, 5 to WR and 7 to Data (corresponding Arduino pins with the latest lib from the playground 4,11,10). 5V is on 16 and GND on 15. This results into the driver Chip getting very very warm, but no lights or anything, no matter what i try. But i must, shame on me, admit that i might have done it wrong. I have a flat cable connected to it and i simply 'think' that the red wire tells me where up and down is and therefore where i have to connect the various pins on the flat wire... could it be that i have to use the 'nose' on the plug as reference and might have done the whole thing mortally wrong?
Have you looked at this thread: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1225239439 ? That's the module you're talking about, right?
Indeed that is it!
I had not seen that page...
Thanks for that link. :)