DigiKeyboard.h

/*
 * 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 


/* We use a simplifed keyboard report descriptor which does not support the
 * boot protocol. We don't allow setting status LEDs and but 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.
 */
PROGMEM char 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 (simultaneous keystrokes) 
  0x75, 0x08,                    //   REPORT_SIZE (8) 
  0x25, 0x65,                    //   LOGICAL_MAXIMUM (101) 
  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_ARROW_LEFT 0x50


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 > 0) {
	    unsigned long now = millis();
	    milli -= now - last;
	    last = now;
	    update();
	  }
	}
  
  void sendKeyStroke(byte keyStroke) {
    sendKeyStroke(keyStroke, 0);
  }

  void sendKeyStroke(byte keyStroke, byte modifiers) {
   	while (!usbInterruptIsReady()) {
      // Note: We wait until we can send keystroke
      //       so we know the previous keystroke was
      //       sent.
    	usbPoll();
    	_delay_ms(5);
    }
    
    memset(reportBuffer, 0, sizeof(reportBuffer));
		
    reportBuffer[0] = modifiers;
    reportBuffer[1] = keyStroke;
    
    usbSetInterrupt(reportBuffer, sizeof(reportBuffer));
		
  	while (!usbInterruptIsReady()) {
      // Note: We wait until we can send keystroke
      //       so we know the previous keystroke was
      //       sent.
    	usbPoll();
    	_delay_ms(5);
    }
      
    // This stops endlessly repeating keystrokes:
    memset(reportBuffer, 0, sizeof(reportBuffer));      
    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[2];    // 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->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS) {
      /* class request type */

      if (rq->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->bRequest == USBRQ_HID_GET_IDLE) {
				//usbMsgPtr = &idleRate;
				//return 1;
				return 0;
				
      } else if (rq->bRequest == USBRQ_HID_SET_IDLE) {
				idleRate = rq->wValue.bytes[1];
				
      }
    } else {
      /* no vendor specific requests implemented */
    }
		
    return 0;
  }
#ifdef __cplusplus
} // extern "C"
#endif


#endif // __DigiKeyboard_h__