USBIN pain

[nicjo]

That might explain why garbage appears on the lcd at switch on, however as its confihured as virtual serial and not pure USB as in hid I would,nt have thought that [0] would be reserved, but it does make me think its worth another look. So you think that the buffer size should be at least 8 bytes?

[pedja089]

I'm not sure, but I think it should be at least 8 bytes...
If you are using CDC, than it maybe different... Best choice is that you leave USB variable, as is. Don't change anything.
And for CDC I think that numbers of bytes in packet is not constant... It can be one, it can be more... But again, I'm not sure... I don't have much experience with usb.

[Demon]

Darn, can't remember where I read about buffer length. I would go with 8 bytes too.

It's not going to affect performance much anyways.

Robert

[Ioannis]

I think it is in USB Complete, but have to search and the book is far away right now...

Ioannis

[DaveC3]

You can have the buffer any length as long as the discriptor is set correctly.

example

USBBufferSizeMax   con 16  ' maximum buffer size
USBBufferSizeTX    con 16  ' input 
USBBufferSizeRX    con 16  ' output

  ; report count (number of fields)
    retlw	0x95
    retlw	0x10   ; 16 byte buffer

it could be 3 bytes, 5 bytes as many as you want up to 64 bytes