Objective Development Forums

I have not attempted to implement the boot protocol myself, but as far as I understand it, all you need to do is to use the standardized report descriptors. New requets (such as SET and GET_PROTOCOL) must be implemented in usbFunctionSetup(). If a request has a data phase, you must expect that usbFu...

Take a look at Automator. This project transfers a block of 512 bytes (the content of the EEPROM) to and from the controller.

Das ist eine Funktion der firmware, die in usbdrv.c verwendet wird und in usbdrvasm.S implementiert ist. Diese Funktion sollte auf der Host-Seite gar nicht erst vorkommen. Kann es sein, dass Du versehentlich usbdrv.c dazu linkst? Oder, wenn es sich um die firmware handelt, dann muss auch usbdrvasm.o...

We recommend the smallest types you can get, which is usually 250 mW. Thanks for posting experimental results with other power ratings!

You need avr-gcc and associated tools to compile any AVRUSB project. Since you have AVRStudio, I assume that you run Windows. I'd recommend WinAVR in this case because it's one big package with everything you need. To change the keys, edit the table keyReport[] in main.c. Remove the modifier (unless...

Du kannst auch die -I Option benutzen um den Include-Suchpfad zu erweitern.

Die firmware laesst sich mit avr-gcc uebersetzen. Ein komplettes Entwicklungssystem bekommst Du mit WinAVR. Da ist der avr-gcc samt allen notwendigen tools und libraries enthalten.

The 1N4148 in Automator is for decoupling, not for ESD protection. Atmel should have a data sheet specifying ESD robustness of the chip. I have not found it in the standard device data sheet, though. They have diodes to V+ and GND on each pin. Designing a REAL ESD protection is not easy. It's not on...

Zener diodes don't have an ideal characteristic curve. The nominal voltage of 3.6 V is only valid for a certain current. With the 68 Ohm series resisotors, you don't reach this current and the 3.6 V diodes come close to 3.3 V.

These circuits are designed to be as simple as possible. The AVR controller itself has some protection against ESD built-in. If you expect a hostile environment, you should add a dedicated ESD protection.

Please have a look at projects based on the ATTiny45, such as i2c-tiny-usb or AVR-CDC.

I don't know what error -75 means, but since you say that the programmer LED flashes, it can't be something fundamental. Avrdude's error message indicates that there was (probably) a timeout in the communication with the target device. I would recommend that you check the ISP levels, levels on the H...

Um das development-System zu testen, probier's bitte einmal mit der host-software von PowerSwitch, unserem Referenzprojekt. Da ist ein Makefile fuer Windows dabei. Wenn sich das uebersetzen laesst, dann funktioniert zumindest das Entwicklungssystem.

I can't see an obvious bug at the first glance. But when you can't find the bug where you are searching, you are probably searching in the wrong place. Can you arrange for SOME kind of debugging output? If not by UART, then maybe at least a port pin which you can toggle when usbFunctionWrite is call...

Maybe I should append:

usbFunctionWrite() is called multiple times with chunks of up to 8 bytes until all 64 bytes are transferred.

My first guess would be that this is a timeout issue. If you disable interrupts for too long (more than ~ 20 CPU cycles), the driver may fail to respond (correctly) to a request from the host. If you have your own interrupt handlers, make sure that the first instruction emitted by the compiler is a ...