Statistics: Posted by rowaweb — Fri Jun 01, 2007 5:03 pm

Statistics: Posted by christian — Thu May 31, 2007 10:47 pm

Statistics: Posted by Guest — Thu May 31, 2007 7:45 pm

Statistics: Posted by christian — Thu May 31, 2007 7:24 pm

Device Class Definition for Human Interface Devices (HID) V1.11 wrote:5.6 Reports

Using USB terminology, a device may send or receive a transaction every USB frame (1 millisecond). A transaction may be made up of multiple packets (token, data, handshake) but is limited in size to 8 bytes for low-speed devices and 64 bytes for high-speed devices. A transfer is one or more transactions creating a set of data that is meaningful to the device—for example, Input, Output, and Feature reports. In this document, a transfer is synonymous with a report.

Most devices generate reports, or transfers, by returning a structure in which each data field is sequentially represented. However, some devices may have multiple report structures on a single endpoint, each representing only a few data fields. For example, a keyboard with an integrated pointing device could independently report “key press” data and “pointing” data over the same endpoint. Report ID items are used to indicate which data fields are represented in each report structure. A Report ID item tag assigns a 1-byte identification prefix to each report transfer. If no Report ID item tags are present in the Report descriptor, it can be assumed that only one Input, Output, and Feature report structure exists and together they represent all of the device’s data.

If a device has multiple report structures, all data transfers start with a 1-byte identifier prefix that indicates which report structure applies to the transfer. This allows the class driver to distinguish incoming pointer data from keyboard data by examining the transfer prefix.

Statistics: Posted by Grendel — Thu May 31, 2007 9:55 am

(...)
    0x09, 0x00,                    //   USAGE (Undefined)
    0xb1, 0x02,                    //   FEATURE (Data,Var,Abs)
    0x85, 0x04,                    //   REPORT_ID (4)
    0x95, 0x40,                    //   REPORT_COUNT (64)
    0x09, 0x00,                    //   USAGE (Undefined)
    0xb1, 0x02,                    //   FEATURE (Data,Var,Abs)

static uchar   textBuffPtr=0;
static uchar   textBuffer[63]= { ... }

uchar   usbFunctionSetup(uchar data[8])
...
       } else if (rq->bRequest == USBRQ_HID_SET_REPORT) {
         if (rq->wValue.bytes[0] == 4) {
            // set 63 byte custom
                        state = STATE_WRITE_KEYBUFFER;   // prepared to receive data
         textBuffPtr = 0;
                        usbWriteLen = rq->wLength.word; // length of Report
                        return 0xff;
}
...

uchar usbFunctionWrite(uchar *data, uchar len)
{

  uchar i;
  
  if (state == STATE_WRITE_KEYBUFFER) {
   if (usbWriteLen == 1+63)     // first chunk to receive
   {
      data++;
      len--;
   }
   
   // to be safe (###)
   if (len > usbWriteLen) len = usbWriteLen;
   
   for(i=0; i<len; i++) {
      textBuffPtr++;
      textBuffer[textBuffPtr] = data[i];
      usbWriteLen--;
   }
   
   
   // return 0 if more data expected
   if (usbWriteLen) return 0;

   state = STATE_IDLE;
   textBuffPtr = 0;
   
   return 1;   
  }

Statistics: Posted by rowaweb — Thu May 31, 2007 12:53 am