Objective Development Forums

They were 500mw D0-35 1n5227b zeners.

I've removed the zeners and the problem appears to have gone away. If I ever need to put them back in for compatability, I suspect I have a voltage level issue I will need to resolve.

It seemed fine overnight last night - could it be a brownout issue? I know the long reset period at startup is supposed to overcome that, but I don't think it can e timing issues - the avr is hardly doing anything but usb right now, with no other interrupts in use.

I've build a device based on the powerswitch demo on an atmega324p, and it works very nicely - until I leave it alone for 10 to 15 minutes. Then, when I try to run the commandline app from ubuntu linux, I get: Warning: cannot query manufacturer for device: error sending control message: Timer expire...

Mystery solved! I need to remember: anytime you see random behavior, first look for open grounds, then look for noise. At the suggestion of eric_j in #avr on freenode, I added a pair of caps, a 47 uf electrolytic and a 0.1 uf across the power near the avr. Suddenly, it all works - both on and off bu...

Since you have made sure that the AVR runs on 12 MHz, the most likely causes are missing zener diodes in 5 V designs or I've got the zeners in the circuit and in the linked schematic, I think - am I missing something? an incorrect initialization of the pins involved for USB. All pins must be config...

I'm building the simplest AVR-USB circuit I can, using the atmega324p and based off of the powerSwitch demo, running completely on external 5v power. When I connect it to linux, I get Feb 20 17:25:02 foo kernel: [66496.580000] usb 1-5: new low speed USB device using ohci_hcd and address 29 Feb 20 17...