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Electronics => Electronics => Topic started by: rbarkas on August 15, 2008, 12:29:58 AM

Title: very simple intelligent I/O controller needed
Post by: rbarkas on August 15, 2008, 12:29:58 AM
I need to find a very simple device that I can program for a specific application.  Hopefully there is something available off the shelf that I can just power up, package, program and use.

Requirements:
The device needs to accept strings of asciii data via a USB port, detect and buffer some of the strings, then periodically access a 3G phone device on another USB port, connect to a network and upload the buffered data.  All the normal stuff like digital outputs to drive fault L.E.D., etc also needed.

Could you point me in the direction of such a device?

Forgive my probable ignorance - I am new to all this.

Thanks in advance for any assistance
Title: Re: very simple intelligent I/O controller needed
Post by: JesseWelling on August 15, 2008, 03:56:41 PM
Sounds like you need more than just a simple microcontroller if you need all of that, specifically the two USB and network thing...
Something like this (http://www.linuxdevices.com/news/NS8479495970.html) may work.
Title: Re: very simple intelligent I/O controller needed
Post by: ArcMan on August 15, 2008, 09:09:50 PM
Micro-ITX boards could be another option.  For example:

http://www.rocketdepot.com/p-1037-intel-d201gly2-microitx-motherboard-with-celeron-215-processor.aspx (http://www.rocketdepot.com/p-1037-intel-d201gly2-microitx-motherboard-with-celeron-215-processor.aspx)

Title: Re: very simple intelligent I/O controller needed
Post by: JesseWelling on August 15, 2008, 11:00:23 PM
The only problem with that is you don't get the GPIO for free, but you could develop it yourself on a 8bit micro taking serial commands from the x86 there... all depends on your power supply and speed requirements I'd say.
Title: Re: very simple intelligent I/O controller needed
Post by: rbarkas on August 15, 2008, 11:20:50 PM
Thanks to all for replys so far.

No really high speed required and low power is very important so micro or nano itx probably won't hack it.

I may have inadequately described the application.  It seems quite simple and un-intellligent to me.

1) sentences of ASCII data arrive on USB 1. 
2) computer looks at sentences and selects some to put into a ring or FIFO buffer.
3) once in a while computer connects via USB 2 to an external device.
4) Once connected computer sends some initialisation info to external device and looks for appropriate response (connect string and reply).
5) once connected computer sends whatever is in the buffer to the device on USB 2
6) once buffer data is sent it is flushed from the buffer and cycle starts again.
Title: Re: very simple intelligent I/O controller needed
Post by: ArcMan on August 16, 2008, 04:31:23 PM
Well, for me anyway, it was the "off-the-shelf" requirement that steered me toward ITX.
I'm a Microchip PIC guy (my wife says that's why she married me  ;D), and I buy pre-made boards by Olimex from Sparkfun.com.  But this board I buy only has one USB port.  I'm personally not aware of an off-the-shelf board with 2 USB ports.
If you bought one of these Olimex boards, you could add another USB port by using another serial-to-USB conversion circuit.  But then it wouldn't be off-the-shelf.
Title: Re: very simple intelligent I/O controller needed
Post by: Iron Man on August 16, 2008, 11:55:28 PM
rbarkas,

I don't know how small your package needs to be, but you might want to try the microchip explorer 16 board.

it comes with two processors on the board.

One is a pic18F4550 which has USB capabilities, but the firmware needs to be updated in order for it work. This should be able to be done via microchip code generator for USB firmware.

the second processors is a 16bit pic24, which you can buy a plug in for that will give it USB capabilities. This is about as off the shelf as i could think of, both would need to be programmed for your purpose, but i believe that the microchip code generator would be able to take care of any of that.

it might be a bit expensive, i don't remember what the explorer 16 boards are running.

@arcman
you work at microchip?
Title: Re: very simple intelligent I/O controller needed
Post by: ArcMan on August 17, 2008, 10:47:32 AM
No.  I'm a control systems engineer.  Big, heavy machinery.  I think designing microchips would make me crazy.
Title: Re: very simple intelligent I/O controller needed
Post by: dunk on August 19, 2008, 04:27:34 AM
hi Rbarkas,
what i'm not clear about from your description is if you intend the I/O controller to be connected directly to a computer that acts as USB host, connects to the network, etc.

if you need a stand alone unit that does not connect to a PC then staying clear of USB will give you far more options.

if you are just talking about a PC peripheral that connects to a PC USB port then there are loads of microcontrollers on the market that will achieve what you ask.


dunk.