USB to Analog output

[UthReal]

I am VERY new with electronics, so please forgive me if this seems trivial or I am using the wrong descriptions for components.

I need something that will take an input from USB, then complete a stand alone circuit.

To make this seem a little easier to explain, how would I control 32 12v LED's from one USB. Using a software I can write to tell the controller what LED to trigger at what time?

I would like the option to choose what voltage I am sending between 1.5v - 12v, I don't know if this is possible using only a USB device, but external power can be solved at a later date. Possibly using relays to trigger the higher 12v. If I am not mistaken USB is powered by 5v?


Any help that could be offered here would be amazing. The only other interface I know that can do this is a PLC that sells for $300+.

 

[mneary]

First, you probably want to apply 12V to your 12V LEDs, and control the brightness by changing the duty cycle. A "12V" LED probably won't light at all with voltages much less than 12V.

There are several microcontrollers that interface directly to USB, either with built in USB hardware or with firmware tricks. Search for your favorite (PIC or AVR) and USB interface.

 

[UthReal]

I'm not actually lighting LED's other then to test the connection for the main control system. The reason I would like to adjust the power is because I am working with electronically triggered fireworks and I want the option to send a 1.5v test signal down the line. The ignitor wont fire until 11.5v, the problem is I still have not revived the data-sheet for the ignitor, so I still dont know if there is a minimum amperage... If so, I will simply use the circuit I am designing to trigger a relay.


But thank you for your help... I have no idea what a PIC or and AVR is, but it points me in the right direction on what to research.

 

[cr0sh]

PIC/AVR are types of microcontrollers; basically small, self-contained computers that you can program to switch outputs on/off and/or receive data from (so, for example, you could - in theory - use a microcontroller to set off your fireworks using MIDI control messages - the microcontroller would "listen" for the message, interpret it, then set an output pin HIGH - like a PLC - which you could use to then switch a transistor to turn on a relay to latch the igniter - music into fireworks launches - sounds cool!).

For this kind of system, aside from the programming required (C/C++), I would say the easiest thing to use would be an Arduino Mega (which is based on the Atmel ATMega1280), which can provide you with 54 digital i/o channels, which will be plenty for your needs. The software to program and control it is easy to use, and there is a large forum community which can help you out, plus plenty of other stuff online. The hardware is fairly inexpensive, and the software is free.

Arduino - HomePage

Arduino - ArduinoBoardMega

**broken link removed**

 

[3v0]

The USB Bitwacker (see my signature) maybe what you are looking for at about $30.