> Hi.  I'm a student here at Penn State, and am working on a group project
> to build a low-speed computer-based oscilloscope.  To achieve this, we
> are using a PIC 16C745 to sample an analog signal, and transmit the data
> over the USB bus.

>We verified that the microcontroller (uC) worked
> properly by making it toggle the output of a port -- so we know the uC
> is working properly.

<GRIN>

> Next, we uploaded the sample code provided with the USB firmware
> (assembly version) into the chip, and wired it up exactly as described
> in the last page of the firmware's documentation.  When we plugged the
> USB cable into the computer, the circuit powered up just fine using the
> USB's 5volt source.  I also checked V-USB, and it is a good 3.3 volts.
> We tried running the chip with a 24 MHz crystal, and with the same 6 MHz
> resonator as drawn up in the firmware documentation.  From the hardware
> side, everything looks like it should...

If no smoke comes out, it's a good start.  ;-)

> On the computer, however, win98 recognizes that a new USB device is
> attached, called %USB\UNKNOWN.DeviceDesc%.

That means that it's probably working, but windows doesn't "recognize" the
device.

>  It also says "no driver
> files loaded".  The device manager initially has the device disabled. If
> we enable it, the device then appears as being "malfunctioning" with a
> yellow exclamation point next to it.  We tried 2 win98 second-edition
> machines, and a win2k laptop -- they all respond the same way.

It sounds to me like the device is working, but you aren't loading a driver.
Are you just pressing "finish" and not loading a driver?  This is precisely
how windoze behaves when you skip loading a driver and winderz doesn't have
one built in.  It sounds like totally normal behavior, you just need a
driver (or at the very least an .inf file for windows to be able to identify
the device)

> Because everything appears to be functioning properly in the hardware,
> we are thinking this may be a driver problem.  Is there a driver for
> windows we need to install to make the sample code work?  Is there some
> debugging utilities you guys have that can help us determine the
> problem?  Do you have any suggestions re: what may be wrong?

I think you need a driver or .inf file.

> Thank you very much for your time,
> Justin Mierta

Your welcome.  ;-)

michael brown

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