Objective Development Forums

Success at last. I had D+ and D- connected incorrectly to PB3 and PB6. Now working fine; I'm happy.

OK, I discovered one issue: I was not using the INT0 pin for D+, since I kept the PB0 and PB2 pin assignments when I ported the code from ATtiny45. Now I switched to PB6=INT0 for D+ and PB3 for D-. But the host still can't communicate with the device. I used an LED to verify that the code invokes th...

I'm still having problems. I now run the AVR at 3.3V with a regulator, to avoid the zener-diode issues. D- is now at 3V at rest, pulled up by a 1.5k. But the host still can't communicate with the device. I tried to see what is going on by turning on an LED at critical points in the code, but I am no...

Thanks. I can try to move the 2.2k resistor to the D- line (right now it's after the 68 Ohm), but I can't see why that would make a difference; the extra 68 Ohm don't make a real difference for a 2.2k. Maybe something else is wrong with my board. I'll try to do some more testing tomorrow with just a...

OK, I see from previous posts that 1w zeners won't work. I switched to 500mW ones (1N5227) and the voltage on D- is till too low, around 2.1v. I changed the 2.2k pullup to 1k, but it only pulls it up to 2.7 or 2.8v, still too low. Should I just reduce the pullup until I get above 3v? Thanks, Sivan

Hi, I built an AVR-USB device using an ATtiny861 with a 16MHz crystal. The clock source works and I can program the chip using ISP. I programmed to it a project to control an I2C device. The chip runs at 5V and the D+ D- lines are protected by 3.6V zeners (but 1W zeners, not low-power ones as sugges...