Objective Development Forums

Yes, I have seen these EMI problems, too. I don't know what causes them, but I know that the processor goes through a RESET. I suspect that the spikes somehow couple to the RESET pin since any connection to this pin makes the problem worse. As far as I remember, I could prove that it's not a watchdo...

Windows is very strict when it checks the consistency of report descriptors and whether the report complies to the descriptor. Usb.org's descriptor tool does not check the consistency of the descriptor at all. You can easily create descriptors which are rejected by Windows. It's easiest to start wit...

You can safely use bits D0 and D2, I do this in all my projects. Please verify your basic configuration: ⋅  Clock frequency. Write a simple test program which uses _delay_ms() from util/delay.h to generate a known frequency and check whether it's correct. The processor has a clock prescale...

All you need to do is to specify your current requirements in the device descriptor. There's an option in usbconfig.h where you specify the power you need from the USB.

The USB driver itself does not use any timers. All it needs is a hardware interrupt (int0) and two I/O pins located on the same port. Have you checked that the AVR really runs on 12 MHz? Did you initialize the I/O pins correctly and are you sure you send the USB reset/disconnect on the correct pins?...

That looks OK to me. You may want to pass an index and a value after CMD_GET to further identify the block, but you don't need to.

If you don't want to spend the extra 128 bytes of RAM for the reply message, you can return -1 and have usbFunctionRead() called to obtain chunks of 8 bytes each.

1 MB is quite a bit of data for a low speed device. You must expect a total transfer time of ~ 2 minutes. I would recommend that you divide the data into chunks of 128 bytes (the driver allows up to 254, but you probably want a power of 2) and read these chunks with a control transfer. You can use t...

At the very end of the page, in section "Download", you can find a link to the project archive. It contains all the projects described on the page.

I have no idea about Delphi and how to use USB from there, but if you don't have very good reasons to use bulk transfers, I would recommend against them. Bulk transfers are not allowed for low speed USB devices, but they are tolerated by Windows and most other operating systems. If you specify a bul...

Please download a new version of the driver with the PowerSwitch project which will be online tomorrow. The new version is 2007-07-19.

We have fixed a minor quirk with SE0 (end of packet) detection. This might help.

If it does not, please get in contact with us through the support form.

Please look at the projects page. There are two IR remote control to USB keyboard converters in the list of HID devices. None of them uses RC5, though, as far as I remember. But it should be easy to change the code to RC5.

Since the suggested code goes into rxChar_poll() only when data is available, there's no delay, at least no delay related to the bit rate. The maximum delay between calls to usbPoll() is documented in usbdrv.h, I think it's 50 ms. One byte sent through asynchronous serial transmission consists of 10...

No, fuse values are NOT stored in the hex file. They are sent to the device in a separate programming session. The fuse values distributed with our project should be correct. But you need to program them with "make fuse". You probably have to change the Makefile if you use a different prog...

Yes, checking for data available on the UART is done via the RXC flag. The while statement should therefore be: while(UCSRA & ( 1 << RXC )){ .... } The watchdog timer is a hardware unit which resets your device when the firmware has crashed. Your firmware must call wdt_...

Please make sure that the AVR is really clocked at 12 MHz. As shipped, the ATMega8 runs on an internal RC oscillator. You must program the fuses for the external crystal oscillator option.

Please run "make fuse" in the project directory to set the fuse values correctly.