| 1 |
On 08/07 11:21, Stefan Mark wrote: |
| 2 |
> On Sun, 6 Aug 2017 18:50:07 +0200 |
| 3 |
> tuxic@××××××.de wrote: |
| 4 |
> |
| 5 |
> > Hi, |
| 6 |
> > |
| 7 |
> > sorry, this will become a little longish... |
| 8 |
> > |
| 9 |
> > Background: To program an ATMEL ATtiny85 via USB |
| 10 |
> > without a dedicated USB chip there is a bootloader |
| 11 |
> > called "micornucleys", which bitbangs the USB protocoll. |
| 12 |
> > This mechanism is used in Digistupms Digispark ATTtiny |
| 13 |
> > developmnent board (http://digistump.com/products/1). |
| 14 |
> > |
| 15 |
> > So far so ....nice? |
| 16 |
> > |
| 17 |
> > When I plug in such a little board into my PC, demesg |
| 18 |
> > reports: |
| 19 |
> > [ 1429.834140] usb 7-4: new low-speed USB device number 15 using |
| 20 |
> > ohci-pci [ 1429.965142] usb 7-4: device descriptor read/64, error -62 |
| 21 |
> > [ 1430.203151] usb 7-4: device descriptor read/64, error -62 |
| 22 |
> > [ 1430.438161] usb 7-4: new low-speed USB device number 16 using |
| 23 |
> > ohci-pci [ 1430.569151] usb 7-4: device descriptor read/64, error -62 |
| 24 |
> > [ 1430.803174] usb 7-4: device descriptor read/64, error -62 |
| 25 |
> > [ 1431.038184] usb 7-4: new low-speed USB device number 17 using |
| 26 |
> > ohci-pci [ 1431.456157] usb 7-4: device not accepting address 17, |
| 27 |
> > error -62 [ 1431.582204] usb 7-4: new low-speed USB device number 18 |
| 28 |
> > using ohci-pci [ 1432.000209] usb 7-4: device not accepting address |
| 29 |
> > 18, error -62 [ 1432.000244] usb usb7-port4: unable to enumerate USB |
| 30 |
> > device |
| 31 |
> > |
| 32 |
> > or similiar. lsusb does not show anything related at all. |
| 33 |
> > |
| 34 |
> That usually happens when the improvised USB is not good enough. Try a |
| 35 |
> different port, maybe put a USB Hub between. Check if the resistors and |
| 36 |
> diodes for the level shifting are the right ones (measure the |
| 37 |
> resistors, especially if you are not using 5% types). If that does not |
| 38 |
> work, try a different diode/resistor combination (For example, usbasp |
| 39 |
> uses 5v6 zener and 68/2k2 resistor, littlewire 3v6 zener and 27/1k2 |
| 40 |
> resistor. I have seen others too. I had at least one which never |
| 41 |
> worked with my laptop). |
| 42 |
|
| 43 |
The board is THAT tiny (http://digistump.com/products/1) that even |
| 44 |
a single proble will short circuit one half of the board... :) |
| 45 |
|
| 46 |
> |
| 47 |
> > As recommended on related pages on the internet, I installed |
| 48 |
> > dedicated udev rules to show the needed ttyACM device. But |
| 49 |
> > since the kernel itsself fails to accept the device, the best |
| 50 |
> > udev rules will not work. |
| 51 |
> > |
| 52 |
> > My first thought was: The micronucleus bootloaed is missing or |
| 53 |
> > is defective... |
| 54 |
> > |
| 55 |
> > But plugging in the board into my Android tablet (the tablet runs |
| 56 |
> > Lollipop and is nothing special at all beside being rooted) via |
| 57 |
> > an OTG cable and using lsusb after that, it shows |
| 58 |
> > Bus 001 Device 003 ID 16d0:0753 MCS Digistump DigiSpark |
| 59 |
> Some ports are more forgiving than others. These soft-usb-thingies tend |
| 60 |
> to be a bit rough, especially the level conversion seems to be a bit |
| 61 |
> icky :) |
| 62 |
> I have a usbasp which works always and everywhere i tested it just |
| 63 |
> perfectly. One of my littlewires is a bit wonky (it sometimes looses |
| 64 |
> connection and needs a few tries until it works again). Another one |
| 65 |
> works fine, but not on every device. |
Archives