I'v got a mips SoC running Linux kernel, 16(maybe 32 if i sacrifice some memory) GPIO pins sitting bored (16 can initiate interrupt). There is also UART port (22MHz clock = very fast, 40ns cycles). I'm evaluating my options about using them :
-IDE/CF interface
-SD/MMC interfase ?
-Camera
-LPT (printserver)
-USB host controller ?
-... ?
I would love to see such a project with a sample code.
-- Like ninjas, true hackers are shrouded in secrecy and mystery. You may never know -- UNTIL IT'S TOO LATE.
was there a question in there somewhere?
I see. you just have some extra pins you dont know what to do with, right? how about this.... build a robotic hand, with thumb and all, and use those pins to control the hand, to come out and jack you off, as desired............ (sorry, in a very cynical mood this morning) lol............ ;-)
I'm sure you can do all those with GPIO. You need to hunt down what those interfaces require as far as protocol. I've heard doing a USB host is a dunting task but I have not done anything with USB myself.
You can use the GPIO bits to talk to an interface chip rather than doing it all in software. You might want to do a google search for such chips.
On Fri, 8 Oct 2004 04:30:38 +0000 (UTC), RusH wrote in comp.arch.embedded:
The notion of doing a USB host controller, even at the 12 Mbs speed of USB 1.1, by bit-banging GPIO, is rather unlikely to be successful.
-- Jack Klein Home: http://JK-Technology.Com FAQs for comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html comp.lang.c++ http://www.parashift.com/c++-faq-lite/alt.comp.lang.learn.c-c++ http://www.contrib.andrew.cmu.edu/~ajo/docs/FAQ-acllc.html
there was, but topposters are in some way immune to thinking.
Pozdrawiam.
-- RusH //
USB is one of those "I dont think so" (thats why the question mark). I have no idea about the speed of GPIO port and USB is kinda fast (12Mbit). I have absolutelly no experience with USB glue chips :(
Low speed USB is another story, that one might be quite easy to implement on those pins (one but - kernel is not realtime).
Pozdrawiam.
-- RusH // http://randki.o2.pl/profil.php?id_r=352019 Like ninjas, true hackers are shrouded in secrecy and mystery. You may never know -- UNTIL IT'S TOO LATE.
Of course I had in mind a USB host controller chip. Memory mapped chips scary me at the moment.
My question was more towards what would be fun / interesting / profitable / to connect with those pins ?
At the moment we got very nice platform for a product. I thing we will start with looking at video_in solutions. Ethernet Camera would be quite a seller.
Pozdrawiam.
-- RusH // http://randki.o2.pl/profil.php?id_r=352019 Like ninjas, true hackers are shrouded in secrecy and mystery. You may never know -- UNTIL IT'S TOO LATE.
re GPIO...
The book "Embedded Linux" by Craig Hollabaugh has a chapter on gpio, using both the parallel port and a memory mapped example. Same text covers SPI and IIC, I think SD/MMC is accessible using one of those...
The book "building embedded Linux Systems" by Karim Yaghmour has some good discussions about flash memory systems, worth a read if you are going to play with compact flash.
Regards Ian McCrum
Thank you, I will look in to those.
Pozdrawiam.
-- RusH // http://randki.o2.pl/profil.php?id_r=352019 Like ninjas, true hackers are shrouded in secrecy and mystery. You may never know -- UNTIL IT'S TOO LATE.
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