I'm looking for a way to use raspberry as a slave usb device.
I noticed that the usb port of the model B/B+/2 is connected to a hub chip (as is the ethernet plug), and then to the processor, so the hardware prevent me from using it as slave, as discussed in this Q&A.
So, i start looking for an external USB chip that i could connect to the rasperry (UART / Serial most probably), and which i can entirely control : Computer <= USB => Chip <= Serial => Rpi
Every chip I found (here for example : http://www.ftdichip.com/) handle the USB protocol itself what I'm looking for, as I really need to do the usb stuff myself.
Do you know a chip that "convert" serial to male USB without handling USB protocol itself, or a USB chip i could program entirely (no protocol handling again, so no firmware ?)