Objective Development Forums

Is this with AVR-Doper? Are you sure that you have chosen the correct serial interface?

The serial interface assigned to AVR-Doper may change when you connect it to a different USB port or insert a hub.

When you use zener diodes, make sure that you use low power types (the tiny ones in the same package as the 1N4148). Higher power types require more current to reach their nominal voltage and have much higher capacitances. The higher capacitance distorts the timing. I would recommend 3.6 V types ove...

This depends on your Linux configuration. As far as I know, you can configure hotplug to set less restrictive permissions for particular USB devices. By default, only root has full access.

Just for your information: We have released EasyLogger 2008-02-28 today. This version adds self-calibration of the RC oscillator. In principle, this calibration algorithm can be used to calibrate the RC oscillator directly to 12 MHz. However, the precision is not high enough for the 12 MHz module (b...

Just for your information: We have released EasyLogger 2008-02-28 today. This version adds self-calibration of the RC oscillator. In principle, this calibration algorithm can be used to calibrate the RC oscillator directly to 12 MHz. However, the precision is not high enough for the 12 MHz module (b...

Just for your information: We have released EasyLogger 2008-02-28 today. This version adds self-calibration of the RC oscillator. In principle, this calibration algorithm can be used to calibrate the RC oscillator directly to 12 MHz. However, the precision is not high enough for the 12 MHz module (b...

Is this the same computer? If not, it may be a hardware problem, e.g. missing zener diodes.

When the PC is in sleep mode, you can wake it with an USB RESET status for a couple of CPU cycles. You could do this with:

Code: Select all

    usbDeviceDisconnect();
    for(i=0;i<10;i++);
    usbDeviceConnect();

If the PC is powered off, this won't help.

Regarding how to enable/disable interrupts: You have to set the interrupt-enable bit for your interrupt in the appropriate register. That's similar to the code in usbInit(). The interrupt handler should not be declared with ISR if you use AVR-USB since it must allow other interrupts. Use UTIL_INTERR...

I don't have Vista so I can't really comment, but I have heard/read that the device should have a serial number. Set one in usbconfig.h and it should work more reliably.

This is possible, of course. In this case you should add a 1 MOhm pull-down resistor on D+ to avoid spurious interrupts. When USB is connected, the driver's interrupt routine handles all necessary requests. When your application sends requests to the device, the function usbFunctionSetup() is called...

A hub, especially a USB 2.0 hub, may have a different timing in the low speed USB communication. Timing dependent bugs may therefore occur or not occur if a hub is inserted.

Yes, this code is intended to handle this. However, it has been developed for the 2313 and it may not be suitable for your pin assignment and AVR type.

Since the device shows up with different addresses in the log file within a period of 2 seconds, I suppose that enumeration fails. 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 an incorrect initialization of the pins involved ...

PowerSwitch actually IS an externally powered device. In order to circumvent some problems when only one power supply is available, the AVR is ALSO powered from the USB.

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