Hi,
On 08/06 07:04, R0b0t1 wrote: > On Sun, Aug 6, 2017 at 11:50 AM, <tu...@posteo.de> wrote: > > When I plug in such a little board into my PC, demesg > > reports: > > [ 1429.834140] usb 7-4: new low-speed USB device number 15 using ohci-pci > > [ 1429.965142] usb 7-4: device descriptor read/64, error -62 > > [ 1430.203151] usb 7-4: device descriptor read/64, error -62 > > [ 1430.438161] usb 7-4: new low-speed USB device number 16 using ohci-pci > > [ 1430.569151] usb 7-4: device descriptor read/64, error -62 > > [ 1430.803174] usb 7-4: device descriptor read/64, error -62 > > [ 1431.038184] usb 7-4: new low-speed USB device number 17 using ohci-pci > > [ 1431.456157] usb 7-4: device not accepting address 17, error -62 > > [ 1431.582204] usb 7-4: new low-speed USB device number 18 using ohci-pci > > [ 1432.000209] usb 7-4: device not accepting address 18, error -62 > > [ 1432.000244] usb usb7-port4: unable to enumerate USB device > > > > > > > My first thought was: The micronucleus bootloaed is missing or > > is defective... > > > > But plugging in the board into my Android tablet (the tablet runs > > Lollipop and is nothing special at all beside being rooted) via > > an OTG cable and using lsusb after that, it shows > > Bus 001 Device 003 ID 16d0:0753 MCS Digistump DigiSpark > > > > What the dmesg output is saying is that your USB hardware has reported > a communication error to the driver. It is my guess that the ATtiny85 > is not meeting the timing requirements for USB. The above is the only part of the dmesg log regarding this usb "device"... If I plug it into a usb-port, it "works"... (read: will be recognized according to dmesg, but still the udev rules dont get triggered, so I still get nothing under /dev/... > Looking at the board there does not seem to be a crystal oscillator > which most people would consider necessary for doing USB > communication. This is an oversight on DigiStump's part and it is very > likely you will not be able to fix the communication issues. You > should contact them and tell them that your computer will not > recognize their device and that you suspect it is because the clock is > too inaccurate. ...the board is a thumbnail thing: http://digistump.com/products/1 No crystal. It is not an original digistum and had cost me less than 1 EUR...so not such a painful loss... > > > > What can I do to make this Digispark being correctly recognized? > > > > Thank you VERY much for any help in advance! > > > > Three things: > > 1) Return the one you bought and get a new one. The ATtiny85's > internal oscillator might be at the end of the bell curve but within > manufacturer tolerance, which isn't enough to produce a USB signal > close enough to the specified frequency. Expect the seller to pay for > return shipping. Returning the board does cost more than the board and I haven't any hope that this will change anything: I have six of them and none works. "The design can be improved..." to be friendly. > 2) You can calibrate the oscillator using instructions in this > application note: > http://www.atmel.com/Images/Atmel-2555-Internal-RC-Oscillator-Calibration-for-tinyAVR-and-megaAVR-Devices_ApplicationNote_AVR053.pdf. > This process still might not get you close enough. I have no oscilloscope nor a frequency counter. That is above my financial possibilities... > 3) Add a crystal oscillator to the ATtiny85 and change its fuses to > use the oscillator. You will need to recompile the firmware if the > crystal is a different frequency from the internal oscillator. There is not enough space on the board. > It might work on your phone and not your desktop because of > differences in the USB hardware (your phone's serial decoder in the > USB hardware performs clock recovery but your PC does not) or because > there are multiple things on a USB hub in your PC and the ATtiny85 is > less accurate than those already present devices. Admittedly I'm > surprised it gets most of the way to registering as a device and then > fails, but I don't think the problem is with the drivers or your > kernel. It's also not very likely to be a problem with the USB code > unless it was reimplemented for DigiStump's product (check against > these libraries > http://www.fourwalledcubicle.com/files/LUFA/Doc/120219/html/_page__alternative_stacks.html). > > R0b0t1. >
