Hi,
I am using arduino duemilanove, and i have following problem, I am using arduino to controll shift registers, through serial communication, and what i noticed is that com port dissappears sometimes, and when i disconnect arduino from usb, to plug in again, there is no com port, what i need to do is disconnect all the i/o from arduino, and then connect to the pc. Then connect all the i/o while running otherwise there is no com port... I dunno if this is computer problem or sth wrong with arduino...

Hmmm, what about maybe doing something like this to get a full range, tell me if this concept is ok

What about measuring the positive voltage, and whenever the voltage hits the 0 which means it will be going to the negative, you use transistor to switch + with -, and then programaticly you just substract the 1023 value (because the reading will be positive again), and then you have the negative reading?

you can use transmiters, to flash with those bulbs, 5V closes the circuit
they are cheap, and if you need only 3 bulbs, you don't need to worry about current supply, I could connect 15 of them, the rest is just to program it how you want to work...

http://www.laro.com.pl/pdf/hm4100f-5v.pdf

I am using 8 shift registers per 3 pins, for totally controlling 225 relays, It worked for me event without transistors, just connected straight to the 595 output, but i supply current to shift registers from pc hard disk cable because there is 5V 12A so enought for that many registers. But actually here I don't care much about refresh rate, because relays maximum switch speed is about 8ms

if you don't have enough current, find right transistor and use it to supply current from somewhere else than arduino

I have this event already in my schedule, will be there for sure. But its only twice a month.

Hello,
I am comming to London tomorrow for an 3 month internship, and was curious If there are people that are meeting to do some stuff together, not quite looking for some paid courses, just to talk and try to do something together. I am playing with arduino for about 1 year, besides of arduino also interested in motion tracking, music synthesis, programming generally in C#

if anybody would like to do some stuff, or already already meeting with some guys , please give me a shout azibmx@gmail.com

i used relays to turn on/off the lights, actually i have 225 of them but like i said couldnt finish this project in one week so here there is only 15 of them + shift registers + bc337 transistor some diodes resistors, the communication between pc and arduino was easy because i had 15x1 pixels bitmaps, and iterating through those bitmap sequences was like rising 2 to power of the pixel number if the color is black what meant that the light should be on, end send it through usb, to arduino, where shiftout library did the rest.

This is a bulb matrix that i have made for the use of this video clip during the time of one week
Not happy enough because did not have enough time to finish it like I wanted ( every bulb could be lighted up separately through application that I wrote in c# ) but will finish it later on

hey guys,
Is it possible to controll dac using 595 shift registers, i could use only 3 pins, or 595's are to slow to generate tones higher than its propagation time??

hello,
I am not sure if this is in VS2005 but there is in VS2008, I wrote that in C#, but in Visual C++, there is the same component in tool box, its called SerialPort, and it's damn easy to send some bytes to arduino... try with that, if you don't know how to use it, let me know I can help you out