Objective Development Forums

USB is a host driven bus. Every activity must be initiated by the host. This gives ugly semantics for things like interrupts but makes the bus logic (and thus the controller chips) much simpler (= cheaper).

Someone also suggested a green and an orange LED in series. The forward voltage should be pretty close to 3.3 V.

Since LEDs can differ depending on efficiency etc, measure the voltage before you use them.

You can save quite a couple of bytes if you don't output the value in decimal. That would save the division code.

Other than that, I'd recommend gcc 3 since it generates shorter code.

Did you do a "make clean" after the change? Most of the makefiles don't have dependencies on usbconfig.h and don't recompile after a change.

Other than that: Are you sure the wiring is OK?

Since you say that you connect a microphone, I assume that you have a sampling rate of more than 8 kHz. AVR-USB is low speed only. The available transfer rate is not enough for one audio channel.

Regarding the HID reports: I usually look for a similar device and check how they did it...

Look at the global variable usbConfiguration. It contains the value of the configuration choosen by the host. However, it is not reset when the device is disconnected. To find out whether your device is disconnected, connect INT0 to D- instead of D+, define USB_COUNT_SOF to 1 and check whether usbSo...

The value you define is in mA, so define it to 500. The USB Spec demands half that value and AVR-USB divides it automatically. Note that you must wait until your device is configured before you draw the full power. Until then you are limited to 100 mA. If you exceed the value, it depends on the host...

If the interrupt is wired to D+, there is only activity when data is actually requested or transferred. If you connect it to D-, you get a couple of cycles every 1 ms frame. Other than that, note that interrupt endpoints are polled and that you have to call usbPoll() in regular intervals. Bulk endpo...

This is example code only. When you write your own device, host and device must agree on numerical values for the requests. This define must be shared between host software and device so that both use the same numerical value.

Hast Du ein scope? Im Prinzip MUSS sich auf der D+ Leitung was tun, sonst koennte er nicht behaupten, dass die enumeration schief gegangen ist. Wenn Du ein Speicherscope hast, trigger auf D+ und schau' nach, ob das device auf ein request antwortet. Meistens kann man die Antwort am leicht anderen Peg...

Don't know. Probably not...

Not just too little memory, the ATTiny x5 has no boot loader section.

You can verify if the uC works correctly if you upload a program which toggles a pin every second and connect an LED to the pin. Then take a stopwatch and count...

Please note that not all orange and green LEDs have the same forward voltage. You must specify exact part types for the LEDs.

We at obdev don't plan to support these chips.