diff --git a/cores/arduino/CDC.cpp b/cores/arduino/CDC.cpp
index 4ff6b9b42..a91a11db2 100644
--- a/cores/arduino/CDC.cpp
+++ b/cores/arduino/CDC.cpp
@@ -215,7 +215,17 @@ void Serial_::flush(void)
 
 size_t Serial_::write(uint8_t c)
 {
-	return write(&c, 1);
+	if (_usbLineInfo.lineState > 0)	{
+		int r = USB_Send(CDC_TX,&c,1);
+		if (r > 0) {
+			return r;
+		} else {
+			setWriteError();
+			return 0;
+		}
+	}
+	setWriteError();
+	return 0;
 }
 
 size_t Serial_::write(const uint8_t *buffer, size_t size)
@@ -257,7 +267,7 @@ Serial_::operator bool() {
 	return result;
 }
 
-unsigned long Serial_::baud() {
+uint32_t Serial_::baud() {
 	// Disable interrupts while reading a multi-byte value
 	uint32_t baudrate;
 	ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
diff --git a/cores/arduino/USBCore.cpp b/cores/arduino/USBCore.cpp
index dc6bc387e..a2895f641 100644
--- a/cores/arduino/USBCore.cpp
+++ b/cores/arduino/USBCore.cpp
@@ -34,6 +34,7 @@ volatile u8 RxLEDPulse; /**< Milliseconds remaining for data Rx LED pulse */
 extern const u16 STRING_LANGUAGE[] PROGMEM;
 extern const u8 STRING_PRODUCT[] PROGMEM;
 extern const u8 STRING_MANUFACTURER[] PROGMEM;
+extern const u8 STRING_SERIAL[] PROGMEM;
 extern const DeviceDescriptor USB_DeviceDescriptorIAD PROGMEM;
 
 const u16 STRING_LANGUAGE[2] = {
@@ -47,6 +48,8 @@ const u16 STRING_LANGUAGE[2] = {
 #endif
 
 const u8 STRING_PRODUCT[] PROGMEM = USB_PRODUCT;
+u8 STRING_PRODUCT_LEN = strlen(USB_PRODUCT);
+u8 const * STRING_PRODUCT_PTR = STRING_PRODUCT;
 
 #if USB_VID == 0x2341
 #  if defined(USB_MANUFACTURER)
@@ -64,6 +67,14 @@ const u8 STRING_PRODUCT[] PROGMEM = USB_PRODUCT;
 #endif
 
 const u8 STRING_MANUFACTURER[] PROGMEM = USB_MANUFACTURER;
+u8 STRING_MANUFACTURER_LEN = strlen(USB_MANUFACTURER);
+u8 const * STRING_MANUFACTURER_PTR = STRING_MANUFACTURER;
+
+#define USB_SERIAL ""
+
+const u8 STRING_SERIAL[] PROGMEM = USB_SERIAL;
+u8 STRING_SERIAL_LEN = strlen(USB_SERIAL);
+u8 const * STRING_SERIAL_PTR = STRING_SERIAL;
 
 
 #define DEVICE_CLASS 0x02
@@ -336,9 +347,10 @@ u8 _initEndpoints[USB_ENDPOINTS] =
 	// Following endpoints are automatically initialized to 0
 };
 
+#define EP_SINGLE_16 0x12
 #define EP_SINGLE_64 0x32	// EP0
 #define EP_DOUBLE_64 0x36	// Other endpoints
-#define EP_SINGLE_16 0x12
+#define EP_DOUBLE_128 0x46	// Other endpoints
 
 static
 void InitEP(u8 index, u8 type, u8 size)
@@ -361,6 +373,8 @@ void InitEndpoints()
 		UECFG1X = EP_SINGLE_16;
 #elif USB_EP_SIZE == 64
 		UECFG1X = EP_DOUBLE_64;
+#elif USB_EP_SIZE == 128
+		UECFG1X = EP_DOUBLE_128;
 #else
 #error Unsupported value for USB_EP_SIZE
 #endif
@@ -519,15 +533,21 @@ bool SendDescriptor(USBSetup& setup)
 			desc_addr = (const u8*)&STRING_LANGUAGE;
 		}
 		else if (setup.wValueL == IPRODUCT) {
-			return USB_SendStringDescriptor(STRING_PRODUCT, strlen(USB_PRODUCT), TRANSFER_PGM);
+			return USB_SendStringDescriptor(STRING_PRODUCT_PTR, STRING_PRODUCT_LEN, TRANSFER_PGM);
 		}
 		else if (setup.wValueL == IMANUFACTURER) {
-			return USB_SendStringDescriptor(STRING_MANUFACTURER, strlen(USB_MANUFACTURER), TRANSFER_PGM);
+			return USB_SendStringDescriptor(STRING_MANUFACTURER_PTR, STRING_MANUFACTURER_LEN, TRANSFER_PGM);
 		}
 		else if (setup.wValueL == ISERIAL) {
 #ifdef PLUGGABLE_USB_ENABLED
 			char name[ISERIAL_MAX_LEN];
 			PluggableUSB().getShortName(name);
+			u8 strLen=strlen(name);
+			if(strLen==0){
+#endif
+				return USB_SendStringDescriptor(STRING_SERIAL_PTR, STRING_SERIAL_LEN, TRANSFER_PGM);
+#ifdef PLUGGABLE_USB_ENABLED
+			}
 			return USB_SendStringDescriptor((uint8_t*)name, strlen(name), 0);
 #endif
 		}
diff --git a/cores/arduino/USBCore.h b/cores/arduino/USBCore.h
index 0c63c2b1f..566f395a7 100644
--- a/cores/arduino/USBCore.h
+++ b/cores/arduino/USBCore.h
@@ -18,6 +18,15 @@
 #ifndef __USBCORE_H__
 #define __USBCORE_H__
 
+extern u8 const * STRING_PRODUCT_PTR;
+extern u8 STRING_PRODUCT_LEN;
+
+extern u8 const * STRING_MANUFACTURER_PTR;
+extern u8 STRING_MANUFACTURER_LEN;
+
+extern u8 const * STRING_SERIAL_PTR;
+extern u8 STRING_SERIAL_LEN;
+
 #include "USBAPI.h"
 
 //	Standard requests
diff --git a/package.json b/package.json
new file mode 100644
index 000000000..d88eddc24
--- /dev/null
+++ b/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "framework-arduino-avr",
+  "version": "9005.1.0",
+  "description": "The official Arduino Wiring-based Framework for Microchip AVR microcontrollers",
+  "keywords": [
+    "framework",
+    "arduino",
+    "microchip",
+    "avr"
+  ],
+  "homepage": "https://www.arduino.cc/reference/en",
+  "license": "LGPL-2.1-or-later",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/Technus/ArduinoCore-avr"
+  }
+}
diff --git a/variants/micro/pins_arduino.h b/variants/micro/pins_arduino.h
index f83ef1f85..ff4bb4866 100644
--- a/variants/micro/pins_arduino.h
+++ b/variants/micro/pins_arduino.h
@@ -28,8 +28,8 @@
 #undef RXLED1
 #undef TX_RX_LED_INIT
 
-#define TXLED0			PORTD &= ~(1<<5)
-#define TXLED1			PORTD |= (1<<5)
-#define RXLED0			PORTB &= ~(1<<0)
-#define RXLED1			PORTB |= (1<<0)
-#define TX_RX_LED_INIT	DDRD |= (1<<5), DDRB |= (1<<0), TXLED0, RXLED0
+#define TXLED0			    PORTF &= ~(1<<1)
+#define TXLED1			    PORTF |= (1<<1)
+#define RXLED0			    PORTF &= ~(1<<0)
+#define RXLED1			    PORTF |= (1<<0)
+#define TX_RX_LED_INIT	DDRF |= (1<<0), DDRF |= (1<<1), TXLED0, RXLED0