Objective Development Forums

Re: SOLVED: How to send mulitple reports over one interrupt

2013-08-28T21:26:44+02:00

its been understood for a long time that Linux will not work with mutiple descriptor reports like that, are you saying you over came that?

like this for example.
viewtopic.php?f=8&t=2926&p=9925&hilit=multi+linux#p9925

Statistics: Posted by ulao — Wed Aug 28, 2013 9:26 pm

Re: How to send mulitple reports over one interrupt endpoint

2013-08-28T03:09:52+02:00

I figured out why the code gets stuck in the loop waiting for usbInterruptIsReady() to return true.

The OS I'm using (Linux) won't poll the USB device unless there is a program actually using the device. In my case I'm running the following command to poll the device.

Code:

jstest --event /dev/input/js0

Which polls the device just fine.

I was also able to reduce USB_CFG_INTR_POLL_INTERVAL to 2ms (not tested on windows).

I managed to get the two reports sending successfully using the following code. - this is mostly inspired by code found on raphnet.net

Code:

    uint8_t must_report = 0;
    while(1) {

        wdt_reset();
        usbPoll(); //this must be called approx every 50ms

        pollButtons(&must_report);

        if (must_report) {
            for (gp = 0; gp < NUM_GAMEPADS; gp++) {
                if (must_report & (1 << gp) == 0)
                    continue;

                if (usbInterruptIsReady()) {
                    buildReport(&gamepads[gp], reportBuffer);
                    usbSetInterrupt(reportBuffer, REPORT_SIZE);
                    must_report &= ~(1 << gp);

                    while (!usbInterruptIsReady()) {
                        usbPoll();
                        wdt_reset();
                        pollButtons(&must_report);
                    }
                }
            }
        }
    }

Statistics: Posted by frampy — Wed Aug 28, 2013 3:09 am

SOLVED: How to send mulitple reports over one interrupt endp

2013-08-28T03:10:23+02:00

I've been building a USB joystick controller for use in an arcade machine using V-USB. I've setup my report descriptor to contain two different reports using the REPORT_ID field (one for each player on tha machine).

I can send a report for each of the players individually, like so.

Code:

if (TCNT0 > 47)  //47 == 4ms approx
{
    if (usbInterruptIsReady())
    {
        // this works fine, but only send a report for player 1
        buildReport(&gamepads[0], reportBuffer);
        usbSetInterrupt(reportBuffer, REPORT_SIZE);
    }
}

But I cannot send both reports squentially, I found some example code at http://www.raphnet.net/electronique/2ne ... dex_en.php which I've used to template this, but it doesn't work for me. Reference the following code sample, after usbSetInterrupt() is called, the code enters a loop waiting for the buffer to clear so we can set another interrupt, but the code gets stuck in this loop and never returns.

Someone help please! Programmer in peril.

Code:

if (TCNT0 > 47) //47 == 4ms approx
{
    TCNT0 = 0;
    for (gp = 0; gp < NUM_GAMEPADS; gp++)
    {
        buildReport(&gamepads[gp], reportBuffer);
        if (usbInterruptIsReady())
        {
            usbSetInterrupt(reportBuffer, REPORT_SIZE);
            while (!usbInterruptIsReady())
            {
                // code hangs in this loop
                usbPoll();
                wdt_reset();

                // when uncommented, this toggles furiously!
                //toggle_pin();
            }
        }
    }
    // never see this toggled
    toggle_pin();
}

Thanks for your time

--Mike

Statistics: Posted by frampy — Tue Aug 27, 2013 11:07 am