I'm using an Arduino Duemilanove and I'm mostly interested in creating my own simple hardware devices to interface with my code. I'm a programmer, and I know very very little about the electronics side of things. I've already created a project with the Arduino that I am now ready to build permanently. It is simply three potentiometers hooked up to control various parts of the Windows 7 volume mixer so that I can independently control game, voice, and music volumes easily without having to tab out of a game.
The problem is that I want the end product to be relatively cheaper than it would be with the whole Arduino inside and USB to serial options that I have been able to find cost nearly as much as the Arduino. The best solution I've figured out I could use a Max 232 chip to create a serial interface and figured I could just use a cheap serial to USB adapter off eBay... however the big serial cord between the two would be less than ideal.
What are my options for interfacing this device via USB considering that I'll need a lot of guidance and I want it to be relatively cheap to implement?
Sorry I can't really help you with your current problem. But hey if your planning on trying to sell those, can i sign up to buy one once u got em working. I tkae it if one was properly setup, while recording a viedo (livestream) of playing a game, I could perhaps use this module to adjust volumes of the game, music I'm playing from Itunes, and friends voices from teamspeak without having to alttab over and do it from the volume mixer (that way it doesnt mess with the recording, but I can mute my friends if their being morons and screaming into their mics to make my video weird). That is a pretty awesome thing to add to a comp. I hope you'll release the code in a manner that I could tell it which programs to link to at a give time.
As far as trying to solve your cost problem. You could try doing a minimalist arduino breadboard setup with a mega chip. Though handproducing several of them and putting them together with all your stuff for the USB would be time consuming and might not even save you that much money. Only other way I can think of would be see if you can build it out of an arduino micro cause they're a little cheaper. But then you'd probably lose the savings in building in the USB chip and a cable.
Really though itd probably be simple enough to use a straight up arduino, I'm assuming for your demo of the sketch your just having the arduino serialmonitorly send the pot values to the program on the computer to manipulate. Using the cheapest full arduino you can get would probably be best cause its already got your USB stuff for you. And then, have a little thing saying that infact their thing is run off of this nifty microcontroller that most anyone who feels like making a little electronics project can use, and have a link back to the arduino forums/getting started in the documentation with your thing your gonna sell. Then there'll probably be more people showing up in the forums if you end up selling a few. And then, if you sell a handful, see if a company will take on producing them for you more cheaply, and make a few bucks selling them.
One thing I say though, use all the analog ports you can for this project, that way you can have more control over the computer without having to leave a program or something.
I'd look at using a Teensy board.
It is very small and has real USB support built in.
http://www.pjrc.com/teensy/
Teensy also has a few libraries to emulate other things like keyboard, mouse, joystick, etc..
This kind of USB capability/support is not possible with the standard Arduino boards as the standard
Arduino boards use a USB to serial chip because the m328/mega AVRs don't have USB
support built into the AVR. When using a USB to serial chip all you get is a USB serial device.
(yes the newer Arduinos have a programmable USB interface chip but I would not waste
any time trying to get it to anything different than the USB to serial function)
If you want to build it youself for super cheap, have a look at using VUSB.
VUSB does the USB in software in the AVR.
The advantage is that the USB interface costs pennies (a couple of resistors and diodes)
Have a look at the VUSB page and the sample projects.
Using VUSB can be a challenge as it requires some pretty good embedded
programming and hardware skills when things don't work straight away.
@Nikarus
I hadn't really considered trying to sell it, but the idea is kind of intriguing if I could cut my costs enough. I suppose I'll explain a bit more about the project itself. The idea is to mount it inside the case from an old broken CD-ROM drive so it can be mounted in a 5.25" drive bay. I planned on adding more controls to the project as I learned and experimented more with the Arduino. So far the only other idea I've had is to add an infrared receiver for a remote control. So far the programs controlled are hard coded, but I intend to add configuration options once I get the circuit figured out better and order some parts (right now I only actually have 2 good pots to play with).
@bperrybap
I looked into VUSB, and it seems like exactly what I want, but I'm not so sure I could successfully implement it... I was unable to find much in the way of guides about how to begin working with it. The teensy looks like a fairly good option too, but still a bit more money that I'd like to spend as a baseline for each project.
What is your target price point?
If the volume is low, (sounds like this is for hobby experimentation),
Then I'm not sure worrying over a couple of $ is worth the work.
Have you added up the total cost of components in your "best case" build it yourself design?
I think in many cases it will be hard to beat the Teensy price ($16) for one off designs,
especially if you are wanting/needing USB connectivity.
Teensy will have more memory, and additional USB capabilities
than a m328 design with USB to serial interface won't have.
For prototyping I really like the Teensy boards because they plug right into a breadboard
and get and supply power from USB.
It makes it really fast and easy to play around with the other parts of the circuit.
For adding USB serial connectivity I'd recommend a cp2102 board like this:
over the board spycatcher used.
The reason being that they have clearly marked holes on the board for all the modem control
signals so it is easy to wire/rewire the cables/connectors to get a auto reset working.