I'm, rather optimistically, looking to build an arduino based Daft Punk table:
From what I have read around the forums / lessons the Max72xx LED Driver is the way to go with this (although I bow to any superior suggestions that anyone might have). What I am thinking about is:
Step one: Scaled down 'proof of concept' 5x5 single LEDs breadboard setup to get some of the code in place.
Step two: Build the basic model (no optional extras). The main question I have is about getting the power to the LEDs. With a 5x5 grid and using a number of high brightness LEDs in each square (the setup in the above link used 8 per square) I'm guessing the arduino probably isn't going to be able to provide the juice for 200+ high brightness LEDs, so an external power supply is probably going to come into play. What I can't get straight in my head is how it would all fit together, any ideas would be greatly appreciated.
Step three: the luxury package, Zigbee connection, SD card reader etc. Not even beginning to think about that yet!
ok, fallen at the first hurdle.... trying to order the max7219 on digikey and there seems to be a number of different options. Am I right in thinking it is the MAX7219CNG+-ND that I should be going for?
personally speaking, for a beginer, the least amount of components possible is going to be the best option for you, so i'd go with the max7219, since its widely supported on the forums and there are several libraries available for you as well on the playground.
i';m at work so i cant check, but if memory serves me correctly, then thats the right chip number you quoted. you can also order samples free from max. dont go over board, but they'll send out a hand full.
Thanks vidiotsquad, I had a look at getting samples but as I am in the UK the postage would cost alot more than just buying them here. Appreciate the suggestion though.
Is there anything else I need to consider before hooking the chip up to my arduino and a bunch of LEDs? Nothing that if I forget my lead to my house burning down or something blowing up?
Also, can I just grab a bag full of LEDs or are there specific ones I need to get (this is for the tester, not the full version)? Any recommendation for high brightness LEDs for the full version too?
no bother chief, i'm in scotland and they sent them with free postage, dunno if they have changed that though, it was a few years back. i've still got a few of them as well!
i got a big bag of 1000 ultra bright blue led's off of fleabay for $20/£10 including postage(so no duty either) ages ago which i find great for most things, but in the uk, somewhere like rapidonline or farnell do cheap basic 3mm leds which will suit your needs for trying things out.
you can set the max to controll any matrix size from 1x1 to 8x8 using the registers, so you can use the 5x5 shape the daft punk table does if you want.
i doubt that you'd burn your house down with such a circuit unless its generating a lot of heat for some reason, so i wouldnt really worry about that just now, just follw the circuit diagrams in the playground and you cant really go wrong. remember to use diffused led's in the final project, they give a better, more even distribution of light under the glass top.
theres some videos and pictures of various led related projects i'm working on just now on my website, i'm an led junkie too!
i'm using the arduino to prototype an interactive touch interface which will either be capacitive or IR sensor based when i'm done. cant decide, both have their pros and cons just now.
i actually built that matrix, since i'm a cheapskate and have soooo many of those blue led's! i drilled a matrix of holes into a piece of black plastic i had and slotted an led into each, then bent all the cathodes down to the next row,soldered them all, and then bent all the anodes to the right to the next anodes, thus creating a matrix.
if you try it, just make sure you get the polarity of the led's right, and bend one leg slightly higher (3mm or so) so the anodes and cathodes dont touch each other, if that makes sense.
the plastic i put on the wave video was a scrap peice of 5mm thick Opal Perspex, which as you can see, creates a cool effect! i get most of the perspex i use for projects from the www.theplasticshop.co.uk for large peices(like table tops) or ebay for smaller, cut to size bits.
I think you may have just spawned my second project! Sitting here and thinking 'How big could I make one of those?' I have a feeling the answer is going to be very big! I'm guessing the plastic would screw up you IR sensors, what range can you get on those?
surprisingly they dont fare too badly with the plastic, and they become fmore of a touch sensor than a distance sensor. the plastic on top creates a very high feedback level of the IR light, but lets enough through to be able to recognise when an object is on top as a bit more IR light is reflected back. i can sense about 20 mm away from the plastic in a dark room, but in a light room its more like 2mm.
i'm working on a 4x4 modules, so i can add more modules when i build them to a table, but i've recently been playing with a new chip that i managed to scam as a sample from someone, its nowhere near as comprehensive as the atmel chips, but their IDE is graphical which is easy to use. apple seem to use them in alot of their products, and it's been a HUGE learning curve to implement it.
I know it is a case of running before you can crawl but.........
what I have in my mind is a large scale matrix of LEDs and IR sensors (something like this Welcome to Willow Technologies) or ultrasonic sensors maybe. Set it all up so that the LEDs light up in the shape of whatever is in front of the sensors, so if you were to stand infront of it you would see an LED silhouette reflection of yourself. Now all I need is to fake being a conceptual artist and a massive Arts Council grant for a 'Community Art Project' and I could probably pull this off!
Having given it a further 30 seconds thought it would probably be a whole lot easier to use a video input (with contrast all the way up and against a white backgorund) and use software to translate the black and white image into the output to the LED matrix. I would love to have this running down a long corridor.
...anyway, back to making that one LED blink in pin 13.
they look expensive! but nice! i just use IR led's and IR photodiodes which are nice and cheap per "pixel".
thats effectively my ultimate goal as well, and something that arduino is definetely capable of. getting an arts council grant is easier said than done though, they dont like us electronics freaks much...
start small, work out how it all works, piece it all together and read loads!! works for me.