can anyone help me? the osillator can work, there are signal on ALE pin, I make the pcb by myself, but we i plug the usb bus, the xp system says that it can detect it ,"unknown device"
is it the problem of at89c5131 (don't have a bootloader ) or the problem of my schematic. wish a expert to help me?
Presumed that the micro is programmed with the firmware, please check the D- and D+ connections connected on the PCB. IF interchanged, nothing will be detected. Too see you get proper 5volts to the microcontroller. Goodluck.
'unknown device' popup means that xp has detected it, but can't find a driver.
What are you expecting?. If you load up Atmel's flip, try to make a connection, it will repeatedly open a DOSbox, which queries the USB port looking for the device. A bootloader sequence on the device should then complete the connection.