i'm working on a button pad and i want to be able to make it send asci values to my computer via usb cable. is there any way to simply output an asci ( might be saying it wrong ) directly from the arduino tx to a usb port, or a ps/2 port and make it think i'm typing certain letters?
just to let you know what i want to acomplush from this:
i have 16 buttons, so i'll have 16 letters sent to my computer. when the program i use called glovepie see's it, then it will turn the letters into midi notes, and then i can use the buttons i have with a progam on my computer called mixcraft ( the windows version of garage band... )
This is very similar to a project I'm working on. Basically I'm making an adapter to convert the serial protocol of an Atari ST keyboard to PS2. You need to implement a PS2 device on your Arduino, which shouldn't be much of a problem.
Take a look at this, which implements both a PS2 device and a host on an Atmega168. The C sources should be easy to adapt to the arduino.
Here's a great little device that I have used to emulate a keyboard, both USB or PS2. People who make arcade controllers use it to translate joystick signals and "fire" and "hyperspace" button presses into keystrokes that a computer can understand. And no Arduino needed! It seems like it would be perfect for your application.
I'm about to build and test the board shown below. It's intended to emulate a USB keyboard, mouse, or joystick and let the Arduino send keypresses, mouse moves, etc to a computer. I built non-shield versions a year or two ago and they work pretty well. Eventual goal is put these up for sale in less than 2 months.
There's not much to it...I'm pretty sure I'll be able to price it somewhere in the $25 neighborhood. The CAD files will also be available if someone wants to build their own. After I make sure it works, of course. Might also have a bare PCB available, the parts are all easily found at Digikey. Nothing smaller than 0805 so it should be a pretty simple soldering job.
follower, the work your doing is very intresting! ( from what i see and read ) it seems like your able to use 4 pins and a b usb connector to send button commands to the computer ( like keyboard buttons a, b, c and so on... )
but , it is exactly what i was looking for... i just make the computer think i'm typing, then use glovepie to set the buttons being sent to midi notes, and bam, i have a button pad that also uses midi ( pretty close to monome )
just to fill you in for the rest of my project ( not important, but i thought you should know ) i'm using sparkfun's 4x4 button pad ( with rgb lights ) to make a usable button interface, and the project ended up becoming so complicated, that for a beginner like me, it's alot easier to use 2 arduino's instead of one. so i have one arduino working all the lights ( which takes up all the pins except 0,1 and one analog input ) and on the second arduino controls the button scanning, and when a button is seen as pressed, it sends a pwm signal to the other arduino via the one open analog input i left to let it know a button is pressed, which makes the ability to control color and such.
you can say it would be similar to monome type projects, but it has rgb led's for more fun, and cant do that one row at a time flashing thing that makes songs...
*** so i was thinking since the second arduino doesent do alot ( only handles the buttons, which i hope and think will not be a tedious task ) hopefully, it can double as a means of connecting my computer to the arduino by means of a usb cable.
and the arduinos will be standalone... no arduino board with them...
i am working on the backpack for the button pad and if i want to add the usb interface, i will need room for it on the backpack. thanks follower!
follower: It's just an ATTiny44 with AVR-USB on it. It's a way to offload the software USB code to another chip, leaving the Arduino unmodified and still able to do heavy processing. It uses the Wire library, unfortunately using up two of the analog inputs. I didn't want users to have to mess with a software I2C implementation.
once again, follower, i just want to stress that what your doing is pretty cool, it opens up doors for alot of fun projects, and i'f i'm able to implement this into my project, anywhere i send the documentation to, just for viewing, i will include your name and such and maybe a few links... this really should be more popular, since your turning the arduino into a flippen usb keyboard!