USB mass storage device on Q26


Is it possible to use the Wavecom Q26 USB interface as a standard USB mass storage device?
Is there some application note or draft to start from?


I think not - I think it’s just a COM/modem device :question:


The USB port on the Q2686 is a USB SLAVE. As awneil says, it’s a modem/com device only.

If you want a quick and simple USB Root device that is easy to interface to embedded controllers, have a look at the Vinculum device produced by FTDI. This device has two USB ports that are configurable in a number of different options, and can be interfaced to the host CPU using UART, SPI or Parallel interfaces.

FTDI also make a number of prototyping modules containing their chip - no PCB design/assy required - just hook up the module and away you go.


WARNING: You will need some form of level shifting interface electronics between the Q2686 and the Vinculum module. The vinculum modules I have used required a 5V power supply, and have 5V I/O. UART1 on the Q2686 has 3V3 tolerant I/O; SPI1/SPI2 are 2V8 I/O and UART2 is 1V8. If you directly connect one of the modules described on the Vinculum website to your Q2686, you will probably let the smoke out of the Q2686. You have been warned…

ciao, Dave

Yes, definitely!

They have mass-storage reference designs - among others…

I gather that the SPI is a bit (!) quirky - so may not be possible to use with Wavecom…? :question:


I’ve had some interesting issues with the Wavecom SPI in the past - although I seem to have it under control now. One of the issues I found with the Wavecom hardware SPI is that it’s not full duplex. The rest of the issues I had were understanding the API doco…

I’m also in the process of interfacing the Vinculum VDRIVE2 module to a PIC 18Fxxxx micro using SPI - so I will know fairly shortly how well the Vinculum SPI has been implemented.

ciao, Dave