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by spiff
Sun Mar 10, 2013 11:15 pm
Forum: V-USB
Topic: USBaspLoader suggestion
Replies: 1
Views: 1727

USBaspLoader suggestion

Hello. I have been using USBaspLoader for a couple of my projects over time, and have been quite happy with it. I do have a feature suggestion, though: I usually do not have a jumper to trigger the boot loader. Instead I use some combination of buttons (usually already on the device), that must be h...
by spiff
Sat Mar 21, 2009 11:21 am
Forum: V-USB
Topic: 1k5 k pull-up on D-
Replies: 8
Views: 9997

First, thanks for your reply. I'm not trying to get into an argument here, but simply understanding where the limitations are. Since the electrical performance and error correction is not up to spec anyway with AVR-USB, the device will never be fully compliant anyways, but it is always nice to take ...
by spiff
Tue Mar 17, 2009 11:06 pm
Forum: V-USB
Topic: 1k5 k pull-up on D-
Replies: 8
Views: 9997

Thanks for your reply. I use a 2k2 resistor to 5V, works fine, uses less power. Shouldn't be a problem since you need a self powered device to met the specs for suspend. Leakage over the Zeneres is probably neglegtable if you use 3V6 ones. Why do I need a self-powered device to meet the specs for su...
by spiff
Tue Mar 17, 2009 12:00 am
Forum: V-USB
Topic: 1k5 k pull-up on D-
Replies: 8
Views: 9997

1k5 k pull-up on D-

I have been developing a few different things based on AVR-USB, and I am currently enhancing my C64 USB keyboard. I have been changing the schematics according to the one suggested by ObDev (with zener-diodes). The reason I want to use this version is to have a 5V supply for the uController. Now, on...
by spiff
Tue Apr 15, 2008 11:58 pm
Forum: V-USB
Topic: AvrUsbBoot on ATmega168
Replies: 5
Views: 5164

Somewhat more sucessful now

OK, I decided to try a newer driver, to see if it would fit in the bootloader section. Turns out it is actually considerably smaller (about 100 bytes) than the one included in the AvrUsbBoot archive. I ported each of the options from the old usbconfig.h, but I am not really sure what VID/PID the old...
by spiff
Tue Apr 15, 2008 11:10 pm
Forum: V-USB
Topic: AvrUsbBoot on ATmega168
Replies: 5
Views: 5164

This is an old note. Recent versions of AVR-USB don't have this requirement any more. If the boot loader fails to work, please check the usual things: fuses, speed selection in usbconfig.h, level conversion for D+ and D- etc. But the version of AVR-USB used for the bootloader is also very old. I ha...
by spiff
Mon Apr 14, 2008 8:25 pm
Forum: V-USB
Topic: Using an Obdev AVR-USB device with Labview
Replies: 7
Views: 7050

But do you think that my device program (that generate a pulse width modulated signal from 1ms to 2ms with a period of 20ms) Since I guess from the timing you are mentioning, that you want to control an RC servo, you should probably look at the USB-Servo projects: http://obdev.at/products/avrusb/pr...
by spiff
Mon Apr 14, 2008 8:16 pm
Forum: V-USB
Topic: AVR-USB frequency meter
Replies: 16
Views: 11250

christian wrote:If you use the input capture unit, you still get an interrupt every cycle. That gives the maximum frequency of ~ 3 kHz.

Is it necessary to generate an interrupt on the input capture. Wouldn't it be possible to just read the captured value from the main loop?
by spiff
Mon Apr 14, 2008 8:14 pm
Forum: V-USB
Topic: AVR_USB timing out?
Replies: 18
Views: 29035

Re: same problem here

while (--j) { /* USB Reset by device only required on Watchdog Reset */ i = 0; while (--i); /* delay >10ms for USB reset */ } I have seen many problems with this construction after switching to a newer avr-gcc (based on gcc4). The delay loops get optimized away. Use _delay...
by spiff
Mon Apr 14, 2008 8:00 pm
Forum: V-USB
Topic: AvrUsbBoot on ATmega168
Replies: 5
Views: 5164

I found a different thread with a problem that could be related: http://forums.obdev.at/viewtopic.php?t=1327 Then I stumbled upon the following in the AvrUsbBoot Makefile: OBJECTS = usbdrv/usbdrv.o usbdrv/usbdrvasm.o usbdrv/oddebug.o main.o # Note that we link usbdrv.o first! This is required for co...
by spiff
Mon Apr 14, 2008 7:42 pm
Forum: V-USB
Topic: AVR-USB frequency meter
Replies: 16
Views: 11250

You can do this with signals up to ~ 3 kHz. This gives an interrupt rate of ~ 300 microseconds which should be compatible with AVR-USB. For higher frequencies, you need a prescaler or simply count input pulses during a given period of time. How about using the event capture function of a timer. Whe...
by spiff
Sun Apr 13, 2008 11:06 pm
Forum: V-USB
Topic: AvrUsbBoot on ATmega168
Replies: 5
Views: 5164

AvrUsbBoot on ATmega168

I have been trying to make AvrUsbBoot work with ATmega168. What I have done is set the appropriate parameters in bootloaderconfig.h, and alter the Makefile appropriately: BOOTLOADER_ADDRESS = 3800 LDFLAGS += -Wl,--section-start=.text=$(BOOTLOADER_ADDRESS) COMPILE = avr-gcc -Wall -Os -Iusbdrv...
by spiff
Mon Jun 18, 2007 11:57 pm
Forum: V-USB
Topic: Making a composite device.
Replies: 5
Views: 7736

Making a composite device.

Hello all. The next step in my C64 USB keyboard implementation is trying to make a composite device that handles both the keyboard and two digital joysticks. I have made each of these work individually, that is two joysticks on one uController and the keyboard on a different one. I tried to create a...
by spiff
Fri Jun 15, 2007 9:45 pm
Forum: V-USB
Topic: USB Keyboard Boot Protocol [solved]
Replies: 7
Views: 9039

Maybe your extensions moved the RAM layout around and the alignment requirements for the USB receive buffer was not met. We have dropped this requirement in the latest version. This is certainly possible. I had seen the discussion about the alignment problem in the header file, but have not done an...
by spiff
Fri Jun 15, 2007 3:29 pm
Forum: V-USB
Topic: USB Keyboard Boot Protocol [solved]
Replies: 7
Views: 9039

Working!

I managed to get this working. It turned out that the problem was related to using an older version of the Obdev stack. :oops: I had simply used the one already in my source directory with my C64 keyboard firmware. I decided to give it a try and downloaded the newest version, and after making approp...

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