Do not send Contact Count (HID Usage 0x54) with USB Touchscreen

teensy3/usb_desc.c

@@ -379,11 +379,11 @@ static uint8_t multitouch_report_desc[] = {
         0x95, 0x01,                     //   Report Count (1)
         0x09, 0x56,                     //   Usage (Scan Time)
         0x81, 0x02,                     //   Input (variable,absolute)
-        0x09, 0x54,                     //   Usage (Contact Count)
-        0x25, MULTITOUCH_FINGERS,       //   Logical Maximum (10)
-        0x75, 0x08,                     //   Report Size (8)
-        0x95, 0x01,                     //   Report Count (1)
-        0x81, 0x02,                     //   Input (variable,absolute)
+        //0x09, 0x54,                     //   Usage (Contact Count)
+        //0x25, MULTITOUCH_FINGERS,       //   Logical Maximum (10)
+        //0x75, 0x08,                     //   Report Size (8)
+        //0x95, 0x01,                     //   Report Count (1)
+        //0x81, 0x02,                     //   Input (variable,absolute)
         0x05, 0x0D,                     //   Usage Page (Digitizers)
         0x09, 0x55,                     //   Usage (Contact Count Maximum)
         0x25, MULTITOUCH_FINGERS,       //   Logical Maximum (10)

teensy3/usb_desc.h

@@ -289,7 +289,7 @@ let me know?  http://forum.pjrc.com/forums/4-Suggestions-amp-Bug-Reports
   #define KEYMEDIA_INTERVAL     4
   #define MULTITOUCH_INTERFACE  3	// Touchscreen
   #define MULTITOUCH_ENDPOINT   5
-  #define MULTITOUCH_SIZE       9
+  #define MULTITOUCH_SIZE       8
   #define MULTITOUCH_FINGERS    10
   #define ENDPOINT1_CONFIG	ENDPOINT_TRANSIMIT_ONLY
   #define ENDPOINT2_CONFIG	ENDPOINT_RECEIVE_ONLY
@@ -329,7 +329,7 @@ let me know?  http://forum.pjrc.com/forums/4-Suggestions-amp-Bug-Reports
   #define MOUSE_INTERVAL        2
   #define MULTITOUCH_INTERFACE  4	// Touchscreen
   #define MULTITOUCH_ENDPOINT   5
-  #define MULTITOUCH_SIZE       9
+  #define MULTITOUCH_SIZE       8
   #define MULTITOUCH_FINGERS    10
   #define ENDPOINT1_CONFIG	ENDPOINT_TRANSIMIT_ONLY
   #define ENDPOINT2_CONFIG	ENDPOINT_RECEIVE_ONLY
@@ -846,7 +846,7 @@ let me know?  http://forum.pjrc.com/forums/4-Suggestions-amp-Bug-Reports
   #define AUDIO_SYNC_ENDPOINT	14
   #define MULTITOUCH_INTERFACE  12	// Touchscreen
   #define MULTITOUCH_ENDPOINT   15
-  #define MULTITOUCH_SIZE       9
+  #define MULTITOUCH_SIZE       8
   #define MULTITOUCH_FINGERS    10
   #define ENDPOINT1_CONFIG	ENDPOINT_TRANSIMIT_ONLY
   #define ENDPOINT2_CONFIG	ENDPOINT_TRANSMIT_AND_RECEIVE

teensy3/usb_touch.c

@@ -85,7 +85,7 @@ void usb_touchscreen_release(uint8_t finger)
 //  5: Y msb
 //  6: scan time lsb
 //  7: scan time msb
-//  8: contact count
+//  (no longer used) 8: contact count
 
 static int usb_touchscreen_transmit(int index, int count)
 {
@@ -100,8 +100,8 @@ static int usb_touchscreen_transmit(int index, int count)
 	*(tx_packet->buf + 5) = ypos[index] >> 8;
 	*(tx_packet->buf + 6) = scan_timestamp;
 	*(tx_packet->buf + 7) = scan_timestamp >> 8;
-	*(tx_packet->buf + 8) = count;
-	tx_packet->len = 9;
+	//*(tx_packet->buf + 8) = count;
+	tx_packet->len = 8;
 	usb_tx(MULTITOUCH_ENDPOINT, tx_packet);
 	return 1;
 }