All,

I am currently using an LPC2148 based custom board with a
USB circuit similar to the Olimex devel board, and am rather new to USB
firmware. I successfully started with the LPCUSB HID example, and have the
following question:

Why can't I replace:

USBHwRegisterFrameHandler(HandleFrame);

with

USBHwRegisterEPIntHandler(INTR_IN_EP, Xmit);

where Xmit is a function defined roughly as:
void Xmit(U8 bEP, U8 bEPStatus)
{
/* Code to fill up abReport array */

USBHwEPWrite(INTR_IN_EP, abReport, REPORT_SIZE);
}
Doing this results in no activity from my device. I was assuming by using
the RegisterEP function with a function handle that that function would be
called only when an EP event had occurred. Using SnoopyPro, I can watch the
initial device handshaking operate correctly, but it stops when the host
starts to ask for IN reports. Works perfectly when I just modify the Frame
Handler function to fill the abReport array.

More questions to follow once this one's out of the way!

Thanks in advance,
Bob


Start a New Thread

USBHwRegisterEPIntHandler() surely register ISR for the endpoint.
However, the endpoint interrupt occurs just when a packet is sent to host.
Until you fill the endpoint buffer first, nothing is sent to host, then no interrupt occurs.

Usually, Set_Configuration handler is the place to initialize variables and flags for USB communication, which are added by you. Unfortunately, there is no hook for Set_Configuration on LPCUSB. The hook is indispensable to give a chance for stack users to initialize their USB communication, when bus reset - re-enumeration occurs.

- Add a hook for callback to Set_Configuration handler.
- In the callback, fill the endpoint buffer with a dummy report.
usbstdreq.c
https://lpcusb.svn.sourceforge.net/svnroot/lpcusb/trunk/target/usbstdreq.c

static Bool HandleStdDeviceReq( ... )
{
...
case REQ_SET_CONFIGURATION:
if (!USBSetConfiguration(pSetup->wValue & 0xFF, 0)) {
DBG("USBSetConfiguration failed!\n");
return FALSE;
}
// configuration successful, update current configuration
bConfiguration = pSetup->wValue & 0xFF;
callback_Set_Config(); // <--------- Add a hook for configuration
break;
void callback_Set_Config( void )
{
/* fill abReport array with a dummy report */

USBHwEPWrite(INTR_IN_EP, abReport, REPORT_SIZE); // put the report to EP buffer
}

Tsuneo

--- In l..., Border Patrol wrote:
>
> All,
>
> I am currently using an LPC2148 based custom board with a
> USB circuit similar to the Olimex devel board, and am rather new to USB
> firmware. I successfully started with the LPCUSB HID example, and have the
> following question:
>
> Why can't I replace:
>
> USBHwRegisterFrameHandler(HandleFrame);
>
> with
>
> USBHwRegisterEPIntHandler(INTR_IN_EP, Xmit);
>
> where Xmit is a function defined roughly as:
> void Xmit(U8 bEP, U8 bEPStatus)
> {
> /* Code to fill up abReport array */
>
> USBHwEPWrite(INTR_IN_EP, abReport, REPORT_SIZE);
> }
> Doing this results in no activity from my device. I was assuming by using
> the RegisterEP function with a function handle that that function would be
> called only when an EP event had occurred. Using SnoopyPro, I can watch the
> initial device handshaking operate correctly, but it stops when the host
> starts to ask for IN reports. Works perfectly when I just modify the Frame
> Handler function to fill the abReport array.
>
> More questions to follow once this one's out of the way!
>
> Thanks in advance,
> Bob
>
>

Start a New Thread