Need help on USB and ATmega32A connection

[monimi]

Hi, i'm having problems with the design of a development board based on Atmega32A which has USB connection.

The development board that i've been designing has the bootloader already loaded (it was loaded using SPI), the problem is that when i plug it on the USB port of my PC, it doesnt recognize the board, and it says that it is an UnknownDevice.

The data lines voltage should be 3.6V, but the output voltage is 4V. The components that i've been using are the following:

2 Resistors 68 ohm
1 Resistor of 1.5K
1 Resistor of 1M
2 Diodes 1N4148 (3.6V and 250mW)
1 Capacitor of 10uF
1 Atmega32A

in the attached files are the schematic, the board design and an image of the physical board. The connections between lines are checked already so there are not short circuits.

if some one could help me it would be really great, i have to finish this project as soon as i can but i have no idea what could be the problem. thanks in advanced.

 

[KlausST]

Hi

You need avr firmware called Usb stack. Usb needs some communication with usb host before being recognized as usb device.

Klaus

 

[monimi]

Hi

You need avr firmware called Usb stack. Usb needs some communication with usb host before being recognized as usb device.

Klaus

Hi, thanks for the reply, i already have the firmware on the microcontroller, i've done the same with atmega16, but with this microcontroller i dont know exactly what is happening, what i am thinking is that the problem is in the hardware but i dont know where could it be.

 

[KlausST]

Hi,

From your post we only can see that you use two port pins of the controller.
In this point there is no difference to M16.

So what controller periferals do you use? Are they absolutely compatible?

Can you use some debug circuit? Maybe a led, with that you can confirm that the codepieces are executed, step by step.

Klaus