be a USB gamepad :)

2 files changed, 55 insertions, 54 deletions

diff --git a/main.c b/main.c
index db2654d..4afe361 100644
--- a/main.c
+++ b/main.c
@@ -51,48 +51,44 @@
 static char buffer[300]; // contains the exploded gamecube bits, i.e. each bit sent/received occupies one byte here.
 
 
-PROGMEM const char usbHidReportDescriptor[52] = { /* USB report descriptor, size must match usbconfig.h */
+PROGMEM const char usbHidReportDescriptor[50] = {
     0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
-    0x09, 0x02,                    // USAGE (Mouse)
-    0xa1, 0x01,                    // COLLECTION (Application)
-    0x09, 0x01,                    //   USAGE (Pointer)
+    0x09, 0x05,                    // USAGE (Game Pad)
+    0xA1, 0x01,                    // COLLECTION (Application)
     0xA1, 0x00,                    //   COLLECTION (Physical)
     0x05, 0x09,                    //     USAGE_PAGE (Button)
-    0x19, 0x01,                    //     USAGE_MINIMUM
-    0x29, 0x03,                    //     USAGE_MAXIMUM
+    0x19, 0x01,                    //     USAGE_MINIMUM (Button 1)
+    0x29, 0x10,                    //     USAGE_MAXIMUM (Button 16)
     0x15, 0x00,                    //     LOGICAL_MINIMUM (0)
     0x25, 0x01,                    //     LOGICAL_MAXIMUM (1)
-    0x95, 0x03,                    //     REPORT_COUNT (3)
+    0x95, 0x10,                    //     REPORT_COUNT (16)
     0x75, 0x01,                    //     REPORT_SIZE (1)
     0x81, 0x02,                    //     INPUT (Data,Var,Abs)
-    0x95, 0x01,                    //     REPORT_COUNT (1)
-    0x75, 0x05,                    //     REPORT_SIZE (5)
-    0x81, 0x03,                    //     INPUT (Const,Var,Abs)
     0x05, 0x01,                    //     USAGE_PAGE (Generic Desktop)
     0x09, 0x30,                    //     USAGE (X)
     0x09, 0x31,                    //     USAGE (Y)
-    0x09, 0x38,                    //     USAGE (Wheel)
+    0x09, 0x32,                    //     USAGE (Z)
+    0x09, 0x33,                    //     USAGE (Rx)
+    0x09, 0x34,                    //     USAGE (Ry)
+    0x09, 0x35,                    //     USAGE (Rz)
     0x15, 0x81,                    //     LOGICAL_MINIMUM (-127)
     0x25, 0x7F,                    //     LOGICAL_MAXIMUM (127)
     0x75, 0x08,                    //     REPORT_SIZE (8)
-    0x95, 0x03,                    //     REPORT_COUNT (3)
-    0x81, 0x06,                    //     INPUT (Data,Var,Rel)
+    0x95, 0x06,                    //     REPORT_COUNT (6)
+    0x81, 0x02,                    //     INPUT (Data,Var,Abs)
     0xC0,                          //   END_COLLECTION
-    0xC0,                          // END COLLECTION
+    0xC0                           // END_COLLECTION
 };
 
-/* This is the same report descriptor as seen in a Logitech mouse. The data
- * described by this descriptor consists of 4 bytes:
- *      .  .  .  .  . B2 B1 B0 .... one byte with mouse button states
- *     X7 X6 X5 X4 X3 X2 X1 X0 .... 8 bit signed relative coordinate x
- *     Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 .... 8 bit signed relative coordinate y
- *     W7 W6 W5 W4 W3 W2 W1 W0 .... 8 bit signed relative coordinate wheel
- */
-typedef struct{
-    uchar   buttonMask;
-    char    dx;
-    char    dy;
-    char    dWheel;
+typedef struct {
+    uchar   btn1;
+    uchar   btn2;
+    char    x;
+    char    y;
+    char    cx;
+    char    cy;
+    uchar   ltrig;
+    uchar   rtrig;
 } report_t;
 
 
@@ -286,6 +282,19 @@ int send_recv_gc(char* bytes, int len)
 		// a value of >=128 means "0", <127 means "1" bit.
 }
 
+/* reads eight exploded bits from bufptr, and makes a 8bit-char from them.
+ * Bit ordering is MSB first. A bit is considered as 1, if bufptr[i] & 0x80 is
+ * *not* set, and vice versa. */
+char decode_byte(char* bufptr)
+{
+	char result=0;
+	for (int i=0;i<8;i++)
+		result|= ( (bufptr[7-i]&0x80)?0:(1<<i) );
+	
+	return result;
+}
+
+
 int main (void)
 {
 	char rand=123;
@@ -336,14 +345,10 @@ debug(4);
 		wdt_reset();
 		usbPoll();
 		
-		if(usbInterruptIsReady()) { // if the interrupt is ready, feed data
-		    // pseudo-random sequence generator, thanks to Dan Frederiksen @AVRfreaks
-		    // http://en.wikipedia.org/wiki/Linear_congruential_generator
-		    rand=(rand*109+89)%251;
-		    
-		    // move to a random direction
-		    reportBuffer.dx = gc_x;
-		    reportBuffer.dy = -gc_y;
+		if(usbInterruptIsReady())
+		{
+		    reportBuffer.x = gc_x;
+		    reportBuffer.y = -gc_y;
 
 		    usbSetInterrupt((void *)&reportBuffer, sizeof(reportBuffer));
 
@@ -388,29 +393,25 @@ debug(4);
 		n_received=send_recv_gc(foo, 3);
 		if (n_received == 64)
 		{
+			
+			gc_y=decode_byte(buffer+24);
+			gc_x=decode_byte(buffer+16);
+			
+			reportBuffer.cx=decode_byte(buffer+32);
+			reportBuffer.cy=decode_byte(buffer+40);
 
-			gc_y=0;
-			for (int i=0;i<8;i++)
-				gc_y|= ( (buffer[23+8-i]&0x80)?0:(1<<i) );
-
-			gc_x=0;
-			for (int i=0;i<8;i++)
-				gc_x|= ( (buffer[23-i]&0x80)?0:(1<<i) );
-
-			//gc_x^=0x80;
-			//gc_y^=0x80;
-
-			gc_x = ((signed char)(((unsigned char) gc_x) - 128)) /8;
-			gc_y = ((signed char)(((unsigned char) gc_y) - 128)) /8;
+			reportBuffer.ltrig=decode_byte(buffer+48);
+			reportBuffer.rtrig=decode_byte(buffer+56);
 
-			char tmp=0;
-			for (int i=1;i<8;i++)
-				tmp|= ( (buffer[i]&0x80)?0:(1<<i) );
+			reportBuffer.btn1=decode_byte(buffer+0);
+			reportBuffer.btn2=decode_byte(buffer+8);
 
-//			if (  (temp & 0xFF) > tmp2 )
-//				tmp|=1;
+			ltrig=decode_byte(buffer+48);
+			rtrig=decode_byte(buffer+56);
+			
+			gc_x = ((signed char)(((unsigned char) gc_x) - 128));
+			gc_y = ((signed char)(((unsigned char) gc_y) - 128));
 
-			//PORTB=~gc_x;
 		}
 		else
 		{
diff --git a/usbdrv/usbconfig.h b/usbdrv/usbconfig.h
index 7bb2a17..a5a0c0a 100644
--- a/usbdrv/usbconfig.h
+++ b/usbdrv/usbconfig.h
@@ -279,7 +279,7 @@ section at the end of this file).
  * HID class is 3, no subclass and protocol required (but may be useful!)
  * CDC class is 2, use subclass 2 and protocol 1 for ACM
  */
-#define USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH    52
+#define USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH    50
 /* Define this to the length of the HID report descriptor, if you implement
  * an HID device. Otherwise don't define it or define it to 0.
  * If you use this define, you must add a PROGMEM character array named