[SOLVED]Device somewhy recognized as full speed
Posted: Sun Jan 04, 2009 8:04 pm
Hello.
I have a little problem with hardware part of avr-usb. My device is recognized as 'full speed', though afaik it should recognize as low speed.
I use Zener diode level conversion. 1.3k resistor between Vcc and D-, 3.3v zeners. I try with 3.3v because I have working USBasp with same 3.3v diodes and 1.3k resistor.
The question is: is there any chance to get stuff working as it is now, or exact 3.6v and 1.5k are necessary?
dmesg output:
EDIT:
I will NEVER EVER use NON-STANDARD usb cables! The one I used is non-standard(different marking for D+ and D-), so I got them swapped -> resistor went to wrong one.
I have a little problem with hardware part of avr-usb. My device is recognized as 'full speed', though afaik it should recognize as low speed.
I use Zener diode level conversion. 1.3k resistor between Vcc and D-, 3.3v zeners. I try with 3.3v because I have working USBasp with same 3.3v diodes and 1.3k resistor.
The question is: is there any chance to get stuff working as it is now, or exact 3.6v and 1.5k are necessary?
dmesg output:
Code: Select all
usb 3-1: device descriptor read/64, error -71
usb 3-1: device descriptor read/64, error -71
usb 3-1: new full speed USB device using uhci_hcd and address 85
usb 3-1: device descriptor read/64, error -71
usb 3-1: device descriptor read/64, error -71
usb 3-1: new full speed USB device using uhci_hcd and address 86
usb 3-1: device not accepting address 86, error -71
usb 3-1: new full speed USB device using uhci_hcd and address 87
usb 3-1: device not accepting address 87, error -71
hub 3-0:1.0: unable to enumerate USB device on port 1EDIT:
I will NEVER EVER use NON-STANDARD usb cables! The one I used is non-standard(different marking for D+ and D-), so I got them swapped -> resistor went to wrong one.