Jbravo wrote:dwc_otg.speed=1 forces usb full-speed (12 Mbit/s), otherwise the usb is running at hi-speed (480 Mbit/s). And since the nic is connected internally via usb there will be a BIG performance penalty with this workaround.
I quite agree. I tried the "dwc_otg.speed=1" suggestion, but I was then lucky if the pi booted up at all. It usually just spewed out errors about faulty devices or cables, so wasn't talking to my USB hub or keyboard or mouse. I had to plug the SD card into another PC so I could remove the dwc_otg bit again.
On a good note. My system is now working after installing the 18th September Raspian Wheezy. I'm using a USB FT232R adapter (might be FT232RL but the specs don't say so.) My early post about trying to install drivers from FTDI is now irrelevant and unnecessary. The built in support is enough. No extra drivers required. (Unfortunately, I had sent a question direct to FTDI about their installation instructions, especially failing to run the ./read.py example, but the unimpressive reply I got was just a copy of the same set of installation instructions! So I'm glad these drivers were not required.)
I've only been running a day and have had issues with ssh sessions failing so needing a power cycle. This could have been provoked by my cron job having issues. I'm not sure, only time will show if it's stable.
For anyone interested, my adapter actually talks RS485 out of an RJ45 socket. Internally the 232 chip talks to 2xMAX485 chips for bidirectional comms. I had a hard job getting this to talk to my inverter, since the pin-outs given were wrong. (It was £8 from china so what did I expect!) I actually fried the adapter initially, but got a very useful friend to replace the blown bits, hence when dismantling, it became apparent the pin-out was wrong. So this is just a suggestion to others with problems - don't assume the Pi is faulty, it could be the wiring. I actually checked everything from a Windows XP laptop!
Anyway, I've written some python to talk to a Fronius IG36TL inverter to log data from my solar panels to local files and to the PVoutput.org website. No additional expensive modules from Fronius were needed as the inverter has an RS485 socket (perhaps RS422?). I'm happy to share the details on request until I find somewhere to post it. The Pi automatically connects to my router wirelessly with an Ralink RT5370 USB adapter. Just like the serial adapter this worked with Raspbian with no extra drivers required.
The only installs I've done were a generic update/upgrade (what's the difference?) and the python-serial module. I hope this is useful to others.