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Re: Microcontrollers USB-Stick
by Olin Lathrop
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Funny NYPD wrote:
> I am a Microchip PIC user, just don't see the high possibility to use
> its USB products so easily very soon.
Then take a look at http://www.embedinc.com/pic/usb.htm. This gives you a
complete end to end bi-directional byte stream between the app on the host
and the application firmware on the PIC. You fill in your device
information in a include file, and all the enumeration is handled for you.
After that, the PIC application calls simple PUT and GET routines to send
and receive single bytes. Under the hood it uses hardware ping-pong
buffering with triple software buffers, but you don't need to know any of
that to make your app work. Pipe 0 is reserved for enumeration and private
communication with the custom driver, and pipe 1 is totally for the
application.
The U1EX firmware is a example on top of the USB routines. It takes about
11% of the program memory of a 18F2550, with the USB routines taking only
8%. The USB routines don't use interrupts so that no addtional interrupt
latency is imposed on the app.
On the host side, there is a custom kernel mode driver and a example library
and application. Each device can be given a unique name, which is stored in
the PIC EEPROM. The driver uses a special protocol over pipe 0 to query the
name of all devices of that VID/PID connected to the system, and allows
applications to enumerate them and connect to a particular one. The example
application provides a command line interface on the host to querying and
setting the device name and turning a LED on and off. The USBProg firmware
and host software provide a more complicated example of using the USB
framework.
We have used this framework for several projects, including our USBProg PIC
programmer. We are also planning on coming out with a USB development board
(http://www.embedinc.com/products/ready02) to make development of PIC usb
devices really easy.
********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014. Gold level PIC consultants since 2000.
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
> I am a Microchip PIC user, just don't see the high possibility to use
> its USB products so easily very soon.
Then take a look at http://www.embedinc.com/pic/usb.htm. This gives you a
complete end to end bi-directional byte stream between the app on the host
and the application firmware on the PIC. You fill in your device
information in a include file, and all the enumeration is handled for you.
After that, the PIC application calls simple PUT and GET routines to send
and receive single bytes. Under the hood it uses hardware ping-pong
buffering with triple software buffers, but you don't need to know any of
that to make your app work. Pipe 0 is reserved for enumeration and private
communication with the custom driver, and pipe 1 is totally for the
application.
The U1EX firmware is a example on top of the USB routines. It takes about
11% of the program memory of a 18F2550, with the USB routines taking only
8%. The USB routines don't use interrupts so that no addtional interrupt
latency is imposed on the app.
On the host side, there is a custom kernel mode driver and a example library
and application. Each device can be given a unique name, which is stored in
the PIC EEPROM. The driver uses a special protocol over pipe 0 to query the
name of all devices of that VID/PID connected to the system, and allows
applications to enumerate them and connect to a particular one. The example
application provides a command line interface on the host to querying and
setting the device name and turning a LED on and off. The USBProg firmware
and host software provide a more complicated example of using the USB
framework.
We have used this framework for several projects, including our USBProg PIC
programmer. We are also planning on coming out with a USB development board
(http://www.embedinc.com/products/ready02) to make development of PIC usb
devices really easy.
********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014. Gold level PIC consultants since 2000.
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
« Return to Thread: Microcontrollers USB-Stick
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