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F1CHF
- 2nd January 2007, 14:26
Hello,
First best wishes for this new year to everybody !
Second : I don't want to reinvent the wheel, so my question is :
Did you "play" with an USB key connected to a "pic"
I mean, I need a huge amount of datas from an external device
(which can be programmed first) to feed a PIC in a On Screen Display system
let say in a OSD page 308 characters are needed (for a full page)
I want to display more than one page, and the contents is not always the same !
I want to have an external device, be able to prepare the pages first and connect this unit to my PIC/OSD system !
May be you have an other solution than USB key ..I2C memory seems too small for this need.
It is possible to use "USB" command for PBP V2.47 in a "simple" way ?
thank in advance for your inputs.
Francois

bitmaniac
- 2nd January 2007, 17:32
1st of all ,Happy New year!

Now to your question:

You have to know that pic can be used only as 'slave' controller and not as 'master' so i is NOT possible to access devices 'from' the pic like usb sticks etc.
USB is a "master-slave" bus with exactly one master and multiple slaves.
The slaves are called peripherals. The master is called a host. Only the
host can initiate USB transfers; the peripherals (PIC) always respond, never
initiate!

F1CHF
- 3rd January 2007, 13:11
Well, thank you for your reply , it's clear
when looking to this item
http://www.mecanique.co.uk/products/usb/easyhid.html
could you tell me if I'm right ?

PIC (same in this example) is connected to a PC through the USB interface

Do you think that I will be able to see a "TEXT FILE" in the PC hard disk
and get the datas with a USBread command (or something else)

If it is possible, I can prepare the TEXT file with a simple method
and feed my PIC (with OSD program imbedded) ?

thanks in advance

Francois F1CHF

mister_e
- 3rd January 2007, 16:30
Yup you could dump a .txt, .bin, .hex or else file from your PC to your PIC by building your own PC software.

F1CHF
- 3rd January 2007, 18:15
Oh year !
Sure I can do it that way, the complete story is that the PIC / OSD system is installed ALONE in a TVA repeater (Radio amateur television) and there is no
PC on the remote site ! that why the solution with the USB key directly
connected to the PIC will be superb, but if it is not possible
I will try with BIG I2C eprom ... I will built a USB/I2C key !
hi ...
Francois F1CHF

SteveB
- 3rd January 2007, 22:57
I will try with BIG I2C eprom ... I will built a USB/I2C key !

I don't know about availability in your location, but I have used the AMTEL AT45DB321C Dataflash (http://www.atmel.com/dyn/products/devices.asp?family_id=616) very successfully. If you're looking for a large storage, PIC friendly solution, it works a treat.

Steve B

mister_e
- 11th January 2007, 18:07
I knew it reminded me something....

i don't know how far those one could go...
http://www.saelig.com/miva/merchant.mvc?Screen=CTGY&Category_Code=FF
http://www.crownhill.co.uk/product.php?prod=1578
http://www.crownhill.co.uk/product.php?prod=1556

but seems to be interesting... worth to read it carefully...

F1CHF
- 11th January 2007, 18:18
My god, i have too much item now ..
I have to understand first
and to order after !

Thanks for your usefull help.

Francois