My problem is I need to control a 7 segment LED circuit (currently on a breadboard, eventually on a PCB). The only option I have from my PC is through USB. The circuit I have built on a breadboard uses 7 segment LED's and 4206 decade counters. I have cut a USB cable in half, and am using the positive and negative leads to power the circuit. I have made multiple attemps at controlling the circuit through the D+ and D- leads, but have failed so far. Basically all I need to do is control the clock input to the 4206 decade counter.
I have made multiple attemps at controlling the circuit through the D+ and D- leads, but have failed so far.
Does anybody know if this is even possible using the D+ and D- leads from the USB? I will eventually attempt to control it through bash script, but don't want to waste my time trying to develop a driver for this circuit if I will not be able to control it.
University of Alabama
Kenneth Ricks
ECE 494 - Capstone Design II (URL's not allowed due to my post count)
Perhaps this article may help ?
No, this won't work. You can't just hook up raw USB signals up to a TTL-level chip and expect it to do anything meaningful. Even if the signals were powerful and noise-free enough for it to do anything, USB's got a very complicated protocol to the point it expects you to tell it how much power your device will consume before it's willing to give you the time of day. You'd better just get an adapter of some sort if you want to make USB controlled leds a project and not a career.
I've used the DLP-IO8 module before and reccomend it. It's pretty simple to use and flexible, plus works with Linux and Windows(uses the FTDI USB-to-serial chip). It acts like a serial port when plugged in. Set it to 115200 baud no parity 8 bits 1 stop bit. Write an ascii '1' to the device and it sets pin one high, write an ascii 'Q' to it and it sets pin 1 low, etc, etc. Other functions include analog input and digital temperature-sensor reading. It provides convenient power hookups. And it's shockingly cheap for what it does. It should control your LEDs fine.