DigiKeyboard BIOS Compatibility

Question

I am using a custom version of the DigiKeyboard library, to use a Digispark as a keyboard in the BIOS. It works on most computers, but HP 730 Thin clients dont recognize it as a keyboard.

Below is the custom version. Any suggestions on how to fix this issue? Thank you in advance for any suggestions/help.

/*
 * Based on Obdev's AVRUSB code and under the same license.
 *
 * TODO: Make a proper file header. :-)
 * Modified for Digispark by Digistump
 */
#ifndef __DigiKeyboard_h__
#define __DigiKeyboard_h__
#include <Arduino.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <avr/delay.h>
#include <string.h>
#include "usbdrv.h"
#include "scancode-ascii-table.h"
// TODO: Work around Arduino 12 issues better.
//#include <WConstants.h>
//#undef int()
typedef uint8_t byte;
#define BUFFER_SIZE 2 // Minimum of 2: 1 for modifiers + 1 for keystroke
static uchar    idleRate;           // in 4 ms units
/* Boot protocols have been added.

We do allow simultaneous key presses.
The report descriptor has been created with usb.org's "HID Descriptor Tool"
which can be downloaded from http://www.usb.org/developers/hidpage/.
Redundant entries (such as LOGICAL_MINIMUM and USAGE_PAGE) have been omitted
for the second INPUT item.

/
const PROGMEM uchar usbHidReportDescriptor[USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH] = { / USB report descriptor */
        0x05, 0x01, // USAGE_PAGE (Generic Desktop)
        0x09, 0x06, // USAGE (Keyboard)
        0xa1, 0x01, // COLLECTION (Application)
        0x05, 0x07, // USAGE_PAGE (Keyboard)
        0x19, 0xe0, // USAGE_MINIMUM (Keyboard LeftControl)
        0x29, 0xe7, // USAGE_MAXIMUM (Keyboard Right GUI)
        0x15, 0x00, // LOGICAL_MINIMUM (0)
        0x25, 0x01, // LOGICAL_MAXIMUM (1)
        0x75, 0x01, // REPORT_SIZE (1)
        0x95, 0x08, // REPORT_COUNT (8)
        0x81, 0x02, // INPUT (Data,Var,Abs)
        0x95, 0x01, // REPORT_COUNT (1)
        0x75, 0x08, // REPORT_SIZE (8)
        0x81, 0x03, // INPUT (Cnst,Var,Abs)
        0x95, 0x05, // REPORT_COUNT (5)
        0x75, 0x01, // REPORT_SIZE (1)
        0x05, 0x08, // USAGE_PAGE (LEDs)
        0x19, 0x01, // USAGE_MINIMUM (Num Lock)
        0x29, 0x05, // USAGE_MAXIMUM (Kana)
        0x91, 0x02, // OUTPUT (Data,Var,Abs)
        0x95, 0x01, // REPORT_COUNT (1)
        0x75, 0x03, // REPORT_SIZE (3)
        0x91, 0x03, // OUTPUT (Cnst,Var,Abs)
        0x95, 0x06, // REPORT_COUNT (6)
        0x75, 0x08, // REPORT_SIZE (8)
        0x15, 0x00, // LOGICAL_MINIMUM (0)
        0x25, 0x65, // LOGICAL_MAXIMUM (101)
        0x05, 0x07, // USAGE_PAGE (Keyboard)
        0x19, 0x00, // USAGE_MINIMUM (Reserved (no event indicated))
        0x29, 0x65, // USAGE_MAXIMUM (Keyboard Application)
        0x81, 0x00, // INPUT (Data,Ary,Abs)
        0xc0 // END_COLLECTION
};
/* Keyboard usage values, see usb.org's HID-usage-tables document, chapter

10 Keyboard/Keypad Page for more codes.

*/
#define MOD_CONTROL_LEFT    (1<<0)
#define MOD_SHIFT_LEFT      (1<<1)
#define MOD_ALT_LEFT        (1<<2)
#define MOD_GUI_LEFT        (1<<3)
#define MOD_CONTROL_RIGHT   (1<<4)
#define MOD_SHIFT_RIGHT     (1<<5)
#define MOD_ALT_RIGHT       (1<<6)
#define MOD_GUI_RIGHT       (1<<7)
#define KEY_A       4
#define KEY_B       5
#define KEY_C       6
#define KEY_D       7
#define KEY_E       8
#define KEY_F       9
#define KEY_G       10
#define KEY_H       11
#define KEY_I       12
#define KEY_J       13
#define KEY_K       14
#define KEY_L       15
#define KEY_M       16
#define KEY_N       17
#define KEY_O       18
#define KEY_P       19
#define KEY_Q       20
#define KEY_R       21
#define KEY_S       22
#define KEY_T       23
#define KEY_U       24
#define KEY_V       25
#define KEY_W       26
#define KEY_X       27
#define KEY_Y       28
#define KEY_Z       29
#define KEY_1       30
#define KEY_2       31
#define KEY_3       32
#define KEY_4       33
#define KEY_5       34
#define KEY_6       35
#define KEY_7       36
#define KEY_8       37
#define KEY_9       38
#define KEY_0       39
#define KEY_ENTER   40
#define KEY_SPACE   44
#define KEY_F1      58
#define KEY_F2      59
#define KEY_F3      60
#define KEY_F4      61
#define KEY_F5      62
#define KEY_F6      63
#define KEY_F7      64
#define KEY_F8      65
#define KEY_F9      66
#define KEY_F10     67
#define KEY_F11     68
#define KEY_F12     69
#define KEY_LEFT        0x50
#define KEY_RIGHT     0x4F
#define KEY_DOWN        0x51
#define KEY_UP          0x52
#define KEY_DEL         0x4C
#define KEY_TAB       0x2B
#define KEY_BACKSP    0x2A
#define KEY_TILDE     0x35
#define KEY_MINUS     0x2D
#define KEY_EQUAL     0x2E
#define KEY_L_BRACE   0x2F
#define KEY_R_BRACE   0x30
#define KEY_BACKSLASH 0x31
#define KEY_SEMICOLON 0x33
#define KEY_QUOTE     0x34
#define KEY_COMMA     0x36
#define KEY_PERIOD    0x37
#define KEY_SLASH     0x38
#define KEY_ESC       0x29
class DigiKeyboardDevice : public Print {
 public:
  DigiKeyboardDevice () {
    cli();
    usbDeviceDisconnect();
    _delay_ms(250);
    usbDeviceConnect();
usbInit();

sei();

// TODO: Remove the next two lines once we fix
//       missing first keystroke bug properly.
memset(reportBuffer, 0, sizeof(reportBuffer));      
usbSetInterrupt(reportBuffer, sizeof(reportBuffer));

}
void update() {
    usbPoll();
  }
// delay while updating until we are finished delaying
void delay(long milli) {
    unsigned long last = millis();
  while (milli &gt; 0) {
    unsigned long now = millis();
    milli -= now - last;
    last = now;
    update();
  }
}


//sendKeyStroke: sends a key press AND release
  void sendKeyStroke(byte keyStroke) {
    sendKeyStroke(keyStroke, 0);
  }
//sendKeyStroke: sends a key press AND release with modifiers
  void sendKeyStroke(byte keyStroke, byte modifiers) {
    sendKeyPress(keyStroke, modifiers);
  delay(10);
    // This stops endlessly repeating keystrokes:
    sendKeyPress(0,0);
  }
//sendKeyPress: sends a key press only - no release
  //to release the key, send again with keyPress=0
  void sendKeyPress(byte keyPress) {
    sendKeyPress(keyPress, 0);
  }
//sendKeyPress: sends a key press only, with modifiers - no release
  //to release the key, send again with keyPress=0
  void sendKeyPress(byte keyPress, byte modifiers) {
    while (!usbInterruptIsReady()) {
      // Note: We wait until we can send keyPress
      //       so we know the previous keyPress was
      //       sent.
        usbPoll();
        _delay_ms(5);
    }
memset(reportBuffer, 0, sizeof(reportBuffer));

reportBuffer[0] = modifiers;
reportBuffer[3] = keyPress;

usbSetInterrupt(reportBuffer, sizeof(reportBuffer));

}
size_t write(uint8_t chr) {
    uint8_t data = pgm_read_byte_near(ascii_to_scan_code_table + (chr - 8));
    sendKeyStroke(data & 0b01111111, data >> 7 ? MOD_SHIFT_RIGHT : 0);
    return 1;
  }
//private: TODO: Make friend?
  uchar    reportBuffer[8];    // buffer for HID reports [ 1 modifier byte + (len-1) key strokes]
  using Print::write;
};
DigiKeyboardDevice DigiKeyboard = DigiKeyboardDevice();
#ifdef __cplusplus
extern "C"{
#endif 
  // USB_PUBLIC uchar usbFunctionSetup
    uchar usbFunctionSetup(uchar data[8]) {
    usbRequest_t    rq = (usbRequest_t )((void *)data);
usbMsgPtr = DigiKeyboard.reportBuffer; //
if ((rq-&gt;bmRequestType &amp; USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS) {
  /* class request type */

  if (rq-&gt;bRequest == USBRQ_HID_GET_REPORT) {
            /* wValue: ReportType (highbyte), ReportID (lowbyte) */

            /* we only have one report type, so don't look at wValue */
    // TODO: Ensure it's okay not to return anything here?    
            return 0;

  } else if (rq-&gt;bRequest == USBRQ_HID_GET_IDLE) {
            //usbMsgPtr = &amp;idleRate;
            //return 1;
            return 0;

  } else if (rq-&gt;bRequest == USBRQ_HID_SET_IDLE) {
            idleRate = rq-&gt;wValue.bytes[1];

  }
} else {
  /* no vendor specific requests implemented */
}

return 0;

}
#ifdef __cplusplus
} // extern "C"
#endif
#endif // DigiKeyboard_h