Objective Development Forums

Its a very common problem when switching to atmel devices. You picked the fuses wrong and choosed a wrong oscillator source. The normal solution is to feed the X1 pin with a 1Mhz clock from another device, like an lm555, living X2 unconnected, and reprogram the fuses with it to the right ones. I had...

You are correct. My mistake. too many errors in the code and in my interpretation. I will try to get real results. EDIT: The problem was a bad use of the "clock" function. The new result is 7182 bytes/s (only the buffer is counted, not protocol bytes). So good realtime adquisition is not p...

How fast can AVR-USB transfer a buffer? I did some tests transferring 5000 times a buffer of 1800 bytes from the uC to PC doing most transfers in chuncks of 250 bytes. The result was a transfer rate of about 55 kb/s. The firmware does nothing more than blink a led each second and transfer the buffe...

The BOOTRST fuse isn't programmed -- try 0xC8 for the high fuse byte. I have now the fuses with C8, but also is not working. It is not being recogniced by linux. Fuses I only changed the boot condition to port D pin 7. #define USB_CFG_IOPORTNAME D #define USB_CFG_DMINUS_BIT 2 #define USB_CFG_DPLUS_...

Could it be caused by the differences between the return values of usbFunctionRead and usbFunctionWrite. The first returns the length of the buffer. And the second returns True or False. I can only suspect that for usbFunctionRead there is an "uchar" variable somewhere acumulating the retu...

Hi i need to transfer a big buffer from an ATmega32 to the computer. For that i have redefined "bytesRemaining" variable from uchar to usbWord_t and made some simple changes to usbFunctionWrite and Read. I test this writing 1800 bytes from the computer to the uC memory and reading it again...

I have succesfully flashed the bootloader, but i cant get it to work. DEVICE = atmega32 BOOTLOADER_ADDRESS = 3800 F_CPU = 16000000 FUSEH = 0xc9 FUSEL = 0xef I can not find more information than this: usb 2-3: new low speed USB device using ohci_hcd and address 29 usb 2-3: device descriptor read/64, ...

I have miss readed the fuses High and Low from the Calculator and burned it swapped.
I always write the High part at the left, and in the calculator it is at the right.

The solution is just to build an oscilator with a 555, 10 nF capacitor and 2 x 470 Ohms resistors.

HI. I am trying to make my previous work with avr-usb bootloadable. For that i needed to change the fuses and the device doesnt work any more. It is an ATmega32, previous fuses were H: 0xC9 L:0xEF It uses an external 16 Mhz Crystal. Now i changed the fuses to H: 0xC9 L:0xE9 to use the biggest boot l...

search for "usbtool" in this forum or the projects page

Hi. Nice done. How have you messured the sample rate? I need to fetch information from ADCs as fast as possible, but i may not need it to be circular. What microcontroller are you using? Crystal oscillator? ADC prescaler settings? How many channels are you sending? etc. How fast can AVR-USB transfer...

In USB you have a Host controller and an endpoint. It seems like you are trying to connect 2 devices with no computer. If so, one of the devices needs to have a host usb module, otherwise it wont work. If all of this is correct on your devices and still doesnt working, it may be that 16 Mhz could be...

Yes it works great with libusb under both OSes. Im glad that it worked for you, then it is not a code problem. It could be that i have windows xp inside a virtual machine, but all other usb devices and libusb-win32 on the same OS works fine. Anyway, using libusb was much easier than the instructions...

All you need for AVR-USB is a supported clock speed (12, 16, 16.5 Mhz), the int0 pin and some other normal pin. You should be able to use the internal usb module with different pins. The datasheet of AT90usb162 says "Up to 16 MIPS Throughput at 16 MHz". So AVR-USB will work fine at 12 or 1...

I dont know this AT90usb, but if it can be used as a host, then he may want to controll another low end device and comunicate with a PC with avrusb.