Hi Alan,
I don't think, that it was the RPi - because now it even works on the
RPi. Furthermore I had the problems before RPi with Ubuntu 12.04 on the
same desktop machine I used to run with 10.04.
In order words, the device now works with the same computer and OS that
it used to fail with before. Then this could be a problem in the
device itself or in the USB connection.
Right.
Now with my RPi:
# dmesg:
[95542.802826] usb 1-1.3: new full-speed USB device number 34 using dwc_otg
[95542.907487] usb 1-1.3: New USB device found, idVendor=04d8,
idProduct=000a
[95542.907531] usb 1-1.3: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[95542.907550] usb 1-1.3: Product: CDC RS-232 Emulation Demo
[95542.907564] usb 1-1.3: Manufacturer: Microchip Technology Inc.
[95542.914838] cdc_acm 1-1.3:1.0: This device cannot do calls on its
own. It is not a modem.
[95542.915160] cdc_acm 1-1.3:1.0: ttyACM0: USB ACM device
[95543.000841] USB Serial support registered for FTDI USB Serial Device
[95543.004692] usbcore: registered new interface driver ftdi_sio
[95543.004721] ftdi_sio: v1.6.0:USB FTDI Serial Converters Driver
I still think, that some change in the code is responsible.
Did you change the software on the RPi between this run and the earlier
runs?
If a software change is responsible, the most likely place is in the
dwc_otg driver.
I did not change anything. No patches, nothing. I just loaded
"usbserial", "cdc_acm" and "ftdi_sio", plugged in the device and it
worked. I added the modules to /etc/modules and the board gets ready
with the RPi boot. Perfect! The only difference is, that I plugged it
once into my notebook with Ubuntu 10.04 (2.6.+).
So - how can the kernel/drivers change the behavior of the device on
other machines?
They can't.
Hmmmmm. Your statement sounds a little bit like "It's hard to believe
you really experienced what you describe" ;-)
But I really tried hard on getting this kernel/hardware combination to
run for weeks...
I don't get it. Is there some kind of firmware uploaded
by the drivers?
If there were, it would show up in the usbmon traces. The failure
traces showed that the device failed during initialization long before
any firmware could be uploaded.
ok. then it really seems like something electrical. Strange.
Does the device have its own power supply, or does it run off of USB
bus power? Removing all power from the device should clear out its
state very quickly (like a fraction of a second) unless it has some
sort of battery or flash memory.
The device is powered by USB bus only. There's no battery. And on my RPi
the current is obviously breaking down as soon as I activate all of the
6 relays on board. Might need another power supply or a powered hub. On
the other side it tells me, that the current isn't a problem in the
first place.
I will keep the device unattached over night. Will see what's going on
tomorrow.
Whats the purpose and functionality of firmware in that case? Has that
chip some kind of Flash ROM?
How would I know? It's _your_ device. :-)
Right :) Thought you might have some experience with the 8bit
controllers from MicroChip.
I'll now continue with programming the interface with python and
pySerial - to see if it's stable.
Today I had some fun programming a python web interface. Until now it
works quiet stable.
Thanks to all of you for racking your brains with me!
Best regards,
Florian
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
