On Fri, Jun 27, 2008 at 01:15:32PM -0400, Joseph Smith wrote:
You will find two PLX Technology NET 2270 chips and a microcontroller (I'm not sure which micro it was, maybe Ubicom SX) responsible for configuration and data flow control in the NET 2270s.
Is the datasheet publicly available?
Yes, but you have to register on their web site.
I'll bet anyone all the electrical components inside that little box can be purchased for less than 20 dollars.
In which quantity?
Maybe when I figure it out, I will buy a big batch and sell them cheaper to those interested:-)
Even if you have to buy 1000 pcs?
So, you will have to reverse engineer the microcontroller software, and re-engineering a software that does what the NET20DC does.
So is there some kind of memory device with the "microcontroller software"? Like a eprom or eeprom??
I expect it to be stored in internal memory in the microcontroller package. I'll open my device up if I can find it to check if I remember correctly about the Ubicom.
You will be learning a lot about USB - which I think is a great idea!
Good, than maybe this little side project will work out great for everyone. Maybe I will learn so much about USB I will be able contribute else where; like filo, GRUB2, and LegacyBIOS :-)
USB has strict distinction between hosts and devices. This is a fundamental design decision detailed pretty well in the spec.
In order to create your own Debug Class device you need to learn a lot about devices and almost nothing about hosts.
When writing a USB stack for the host one needs to learn everything about the Host Controller and almost nothing about devices.
Also, another question about this topic. I read somewhere someone was working on a Linux Kernel driver for the NET20DC for the host PC. Did this ever implimented? Can you use the NET20DC in linux on a host PC?
Yes.
If so, how does it work?
USB serial port. CONFIG_USB_SERIAL_DEBUG enables the driver.
//Peter