diff --git a/CMakeLists.txt b/CMakeLists.txt
index cdb1f079..cd228a07 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -32,6 +32,7 @@ set(CORE_SRCS
   cores/esp32/stdlib_noniso.c
   cores/esp32/Stream.cpp
   cores/esp32/StreamString.cpp
+  cores/esp32/HWCDC.cpp
   cores/esp32/USB.cpp
   cores/esp32/USBCDC.cpp
   cores/esp32/USBMSC.cpp
diff --git a/boards.txt b/boards.txt
index 138cbcdb..abc77f9e 100644
--- a/boards.txt
+++ b/boards.txt
@@ -21,12 +21,16 @@ menu.EventsCore=Events Run On
 ##############################################################
 
 esp32c3.name=ESP32C3 Dev Module
+esp32c3.vid.0=0x303a
+esp32c3.pid.0=0x1001
 
 esp32c3.upload.tool=esptool_py
 esp32c3.upload.maximum_size=1310720
 esp32c3.upload.maximum_data_size=327680
 esp32c3.upload.flags=
 esp32c3.upload.extra_flags=
+esp32c3.upload.use_1200bps_touch=false
+esp32c3.upload.wait_for_upload_port=false
 
 esp32c3.serial.disableDTR=false
 esp32c3.serial.disableRTS=false
@@ -48,6 +52,18 @@ esp32c3.build.boot=qio
 esp32c3.build.partitions=default
 esp32c3.build.defines=
 
+esp32c3.menu.CDCOnBoot.default=Disabled
+esp32c3.menu.CDCOnBoot.default.build.cdc_on_boot=0
+esp32c3.menu.CDCOnBoot.cdc=Enabled
+esp32c3.menu.CDCOnBoot.cdc.build.cdc_on_boot=1
+
+esp32c3.menu.UploadMode.default=UART0
+esp32c3.menu.UploadMode.default.upload.use_1200bps_touch=false
+esp32c3.menu.UploadMode.default.upload.wait_for_upload_port=false
+esp32c3.menu.UploadMode.cdc=Internal USB
+esp32c3.menu.UploadMode.cdc.upload.use_1200bps_touch=true
+esp32c3.menu.UploadMode.cdc.upload.wait_for_upload_port=true
+
 esp32c3.menu.PartitionScheme.default=Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
 esp32c3.menu.PartitionScheme.default.build.partitions=default
 esp32c3.menu.PartitionScheme.defaultffat=Default 4MB with ffat (1.2MB APP/1.5MB FATFS)
diff --git a/cores/esp32/HWCDC.cpp b/cores/esp32/HWCDC.cpp
new file mode 100644
index 00000000..05cb816f
--- /dev/null
+++ b/cores/esp32/HWCDC.cpp
@@ -0,0 +1,283 @@
+// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#include "USB.h"
+#if CONFIG_IDF_TARGET_ESP32C3
+
+#include "esp32-hal.h"
+#include "HWCDC.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/semphr.h"
+#include "freertos/queue.h"
+#include "freertos/ringbuf.h"
+#include "esp_intr_alloc.h"
+#include "soc/periph_defs.h"
+#include "hal/usb_serial_jtag_ll.h"
+
+static RingbufHandle_t tx_ring_buf = NULL;
+static xQueueHandle rx_queue = NULL;
+static uint8_t rx_data_buf[64];
+static intr_handle_t intr_handle = NULL;
+static volatile bool initial_empty = false;
+
+static void hw_cdc_isr_handler(void *arg) {
+    portBASE_TYPE xTaskWoken = 0;
+    uint32_t usbjtag_intr_status = 0;
+    usbjtag_intr_status = usb_serial_jtag_ll_get_intsts_mask();
+
+    if (usbjtag_intr_status & USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY) {
+        // Interrupt tells us the host picked up the data we sent.
+        if (usb_serial_jtag_ll_txfifo_writable() == 1) {
+            // We disable the interrupt here so that the interrupt won't be triggered if there is no data to send.
+            usb_serial_jtag_ll_disable_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+
+            if(!initial_empty){
+                initial_empty = true;
+                //send event?
+                //ets_printf("CONNECTED\n");
+            }
+            size_t queued_size;
+            uint8_t *queued_buff = (uint8_t *)xRingbufferReceiveUpToFromISR(tx_ring_buf, &queued_size, 64);
+            // If the hardware fifo is avaliable, write in it. Otherwise, do nothing.
+            if (queued_buff != NULL) {  //Although tx_queued_bytes may be larger than 0. We may have interrupt before xRingbufferSend() was called.
+                //Copy the queued buffer into the TX FIFO
+                usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+                usb_serial_jtag_ll_write_txfifo(queued_buff, queued_size);
+                usb_serial_jtag_ll_txfifo_flush();
+                vRingbufferReturnItemFromISR(tx_ring_buf, queued_buff, &xTaskWoken);
+                usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+                //send event?
+                //ets_printf("TX:%u\n", queued_size);
+            }
+        } else {
+            usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+        }
+    }
+
+    if (usbjtag_intr_status & USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT) {
+        // read rx buffer(max length is 64), and send avaliable data to ringbuffer.
+        // Ensure the rx buffer size is larger than RX_MAX_SIZE.
+        usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT);
+        uint32_t rx_fifo_len = usb_serial_jtag_ll_read_rxfifo(rx_data_buf, 64);
+        uint32_t i=0;
+        for(i=0; i<rx_fifo_len; i++){
+            if(rx_queue == NULL || !xQueueSendFromISR(rx_queue, rx_data_buf+i, &xTaskWoken)){
+                break;
+            }
+        }
+        //send event?
+        //ets_printf("RX:%u/%u\n", i, rx_fifo_len);
+    }
+
+    if (usbjtag_intr_status & USB_SERIAL_JTAG_INTR_BUS_RESET) {
+        usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_BUS_RESET);
+        initial_empty = false;
+        usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+        //ets_printf("BUS_RESET\n");
+    }
+
+    if (xTaskWoken == pdTRUE) {
+        portYIELD_FROM_ISR();
+    }
+}
+
+static void ARDUINO_ISR_ATTR cdc0_write_char(char c) {
+    if(xPortInIsrContext()){
+        xRingbufferSendFromISR(tx_ring_buf, (void*) (&c), 1, NULL);
+    } else {
+        xRingbufferSend(tx_ring_buf, (void*) (&c), 1, 0);
+    }
+    usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+}
+
+HWCDC::HWCDC() {
+    
+}
+
+HWCDC::~HWCDC(){
+    end();
+}
+
+HWCDC::operator bool() const
+{
+    return initial_empty;
+}
+
+void HWCDC::begin(unsigned long baud)
+{
+    setRxBufferSize(256);//default if not preset
+    setTxBufferSize(256);//default if not preset
+
+    usb_serial_jtag_ll_clr_intsts_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY | USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT | USB_SERIAL_JTAG_INTR_BUS_RESET);
+    usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY | USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT | USB_SERIAL_JTAG_INTR_BUS_RESET);
+    if(!intr_handle && esp_intr_alloc(ETS_USB_INTR_SOURCE/*ETS_USB_SERIAL_JTAG_INTR_SOURCE*/, 0, hw_cdc_isr_handler, NULL, &intr_handle) != ESP_OK){
+        isr_log_e("HW USB CDC failed to init interrupts");
+        end();
+    }
+}
+
+void HWCDC::end()
+{
+    //Disable tx/rx interrupt.
+    usb_serial_jtag_ll_disable_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY | USB_SERIAL_JTAG_INTR_SERIAL_OUT_RECV_PKT | USB_SERIAL_JTAG_INTR_BUS_RESET);
+    esp_intr_free(intr_handle);
+    intr_handle = NULL;
+    setRxBufferSize(0);
+    setTxBufferSize(0);
+}
+
+/*
+ * WRITING
+*/
+
+size_t HWCDC::setTxBufferSize(size_t tx_queue_len){
+    if(tx_ring_buf){
+        if(!tx_queue_len){
+            vRingbufferDelete(tx_ring_buf);
+            tx_ring_buf = NULL;
+        }
+        return 0;
+    }
+    tx_ring_buf = xRingbufferCreate(tx_queue_len, RINGBUF_TYPE_BYTEBUF);
+    if(!tx_ring_buf){
+        return 0;
+    }
+    return tx_queue_len;
+}
+
+int HWCDC::availableForWrite(void)
+{
+    if(tx_ring_buf == NULL){
+        return -1;
+    }
+    return xRingbufferGetCurFreeSize(tx_ring_buf);
+}
+
+size_t HWCDC::write(const uint8_t *buffer, size_t size)
+{
+    // Blocking method, Sending data to ringbuffer, and handle the data in ISR.
+    if(xRingbufferSend(tx_ring_buf, (void*) (buffer), size, 200 / portTICK_PERIOD_MS) != pdTRUE){
+        log_e("Write Failed");
+        return 0;
+    }
+    // Now trigger the ISR to read data from the ring buffer.
+    usb_serial_jtag_ll_ena_intr_mask(USB_SERIAL_JTAG_INTR_SERIAL_IN_EMPTY);
+    return size;
+}
+
+size_t HWCDC::write(uint8_t c)
+{
+    return write(&c, 1);
+}
+
+void HWCDC::flush(void)
+{
+    if(tx_ring_buf == NULL){
+        return;
+    }
+    UBaseType_t uxItemsWaiting = 0;
+    vRingbufferGetInfo(tx_ring_buf, NULL, NULL, NULL, NULL, &uxItemsWaiting);
+    while(uxItemsWaiting){
+        delay(5);
+        vRingbufferGetInfo(tx_ring_buf, NULL, NULL, NULL, NULL, &uxItemsWaiting);
+    }
+}
+
+/*
+ * READING
+*/
+
+size_t HWCDC::setRxBufferSize(size_t rx_queue_len){
+    if(rx_queue){
+        if(!rx_queue_len){
+            vQueueDelete(rx_queue);
+            rx_queue = NULL;
+        }
+        return 0;
+    }
+    rx_queue = xQueueCreate(rx_queue_len, sizeof(uint8_t));
+    if(!rx_queue){
+        return 0;
+    }
+    if(!tx_ring_buf){
+        tx_ring_buf = xRingbufferCreate(rx_queue_len, RINGBUF_TYPE_BYTEBUF);
+    }
+    return rx_queue_len;
+}
+
+int HWCDC::available(void)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    return uxQueueMessagesWaiting(rx_queue);
+}
+
+int HWCDC::peek(void)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    uint8_t c;
+    if(xQueuePeek(rx_queue, &c, 0)) {
+        return c;
+    }
+    return -1;
+}
+
+int HWCDC::read(void)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    uint8_t c = 0;
+    if(xQueueReceive(rx_queue, &c, 0)) {
+        return c;
+    }
+    return -1;
+}
+
+size_t HWCDC::read(uint8_t *buffer, size_t size)
+{
+    if(rx_queue == NULL){
+        return -1;
+    }
+    uint8_t c = 0;
+    size_t count = 0;
+    while(count < size && xQueueReceive(rx_queue, &c, 0)){
+        buffer[count++] = c;
+    }
+    return count;
+}
+
+/*
+ * DEBUG
+*/
+
+void HWCDC::setDebugOutput(bool en)
+{
+    if(en) {
+        uartSetDebug(NULL);
+        ets_install_putc1((void (*)(char)) &cdc0_write_char);
+    } else {
+        ets_install_putc1(NULL);
+    }
+}
+
+#if ARDUINO_HW_CDC_ON_BOOT //Serial used for USB CDC
+HWCDC Serial;
+#else
+HWCDC USBSerial;
+#endif
+
+#endif /* CONFIG_TINYUSB_CDC_ENABLED */
diff --git a/cores/esp32/HWCDC.h b/cores/esp32/HWCDC.h
new file mode 100644
index 00000000..6551425d
--- /dev/null
+++ b/cores/esp32/HWCDC.h
@@ -0,0 +1,82 @@
+// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#pragma once
+
+#include "sdkconfig.h"
+#if CONFIG_IDF_TARGET_ESP32C3
+
+#include <inttypes.h>
+#include "Stream.h"
+
+class HWCDC: public Stream
+{
+public:
+    HWCDC();
+    ~HWCDC();
+
+    size_t setRxBufferSize(size_t);
+    size_t setTxBufferSize(size_t);
+    void begin(unsigned long baud=0);
+    void end();
+    
+    int available(void);
+    int availableForWrite(void);
+    int peek(void);
+    int read(void);
+    size_t read(uint8_t *buffer, size_t size);
+    size_t write(uint8_t);
+    size_t write(const uint8_t *buffer, size_t size);
+    void flush(void);
+    
+    inline size_t read(char * buffer, size_t size)
+    {
+        return read((uint8_t*) buffer, size);
+    }
+    inline size_t write(const char * buffer, size_t size)
+    {
+        return write((uint8_t*) buffer, size);
+    }
+    inline size_t write(const char * s)
+    {
+        return write((uint8_t*) s, strlen(s));
+    }
+    inline size_t write(unsigned long n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(long n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(unsigned int n)
+    {
+        return write((uint8_t) n);
+    }
+    inline size_t write(int n)
+    {
+        return write((uint8_t) n);
+    }
+    operator bool() const;
+    void setDebugOutput(bool);
+    uint32_t baudRate(){return 115200;}
+
+};
+
+#if ARDUINO_HW_CDC_ON_BOOT //Serial used for USB CDC
+extern HWCDC Serial;
+#else
+extern HWCDC USBSerial;
+#endif
+
+#endif /* CONFIG_IDF_TARGET_ESP32C3 */
diff --git a/cores/esp32/HardwareSerial.cpp b/cores/esp32/HardwareSerial.cpp
index 32411514..064aef6f 100644
--- a/cores/esp32/HardwareSerial.cpp
+++ b/cores/esp32/HardwareSerial.cpp
@@ -76,6 +76,8 @@ void serialEvent2(void) {}
 #if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_SERIAL)
 #if ARDUINO_USB_CDC_ON_BOOT //Serial used for USB CDC
 HardwareSerial Serial0(0);
+#elif ARDUINO_HW_CDC_ON_BOOT
+HardwareSerial Serial0(0);
 #else
 HardwareSerial Serial(0);
 #endif
@@ -91,6 +93,8 @@ void serialEventRun(void)
 {
 #if ARDUINO_USB_CDC_ON_BOOT //Serial used for USB CDC
     if(Serial0.available()) serialEvent();
+#elif ARDUINO_HW_CDC_ON_BOOT
+    if(Serial0.available()) serialEvent();
 #else
     if(Serial.available()) serialEvent();
 #endif
diff --git a/cores/esp32/HardwareSerial.h b/cores/esp32/HardwareSerial.h
index 04b96045..40282361 100644
--- a/cores/esp32/HardwareSerial.h
+++ b/cores/esp32/HardwareSerial.h
@@ -50,6 +50,7 @@
 #include "Stream.h"
 #include "esp32-hal.h"
 #include "soc/soc_caps.h"
+#include "HWCDC.h"
 
 class HardwareSerial: public Stream
 {
@@ -121,6 +122,8 @@ extern void serialEventRun(void) __attribute__((weak));
 #include "USB.h"
 #include "USBCDC.h"
 extern HardwareSerial Serial0;
+#elif ARDUINO_HW_CDC_ON_BOOT
+extern HardwareSerial Serial0;
 #else
 extern HardwareSerial Serial;
 #endif
diff --git a/platform.txt b/platform.txt
index 2fa972dc..d76c6212 100644
--- a/platform.txt
+++ b/platform.txt
@@ -60,7 +60,7 @@ compiler.cpp.flags.esp32c3=-march=rv32imc -ffunction-sections -fdata-sections -W
 compiler.S.flags.esp32c3=-ffunction-sections -fdata-sections -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=deprecated-declarations -Wno-unused-parameter -Wno-sign-compare -ggdb -Wno-error=format= -nostartfiles -Wno-format -Og -fstrict-volatile-bitfields -Wno-error=unused-but-set-variable -fno-jump-tables -fno-tree-switch-conversion  -x assembler-with-cpp -MMD -c
 compiler.c.elf.flags.esp32c3=-T memory.ld -T sections.ld -T esp32c3.rom.ld -T esp32c3.rom.api.ld -T esp32c3.rom.libgcc.ld -T esp32c3.rom.newlib.ld -T esp32c3.rom.version.ld -T esp32c3.peripherals.ld  -nostartfiles -march=rv32imc --specs=nosys.specs -Wl,--cref -Wl,--gc-sections -fno-rtti -fno-lto -u _Z5setupv -u _Z4loopv -Wl,--wrap=mbedtls_mpi_exp_mod -u esp_app_desc -u pthread_include_pthread_impl -u pthread_include_pthread_cond_impl -u pthread_include_pthread_local_storage_impl -u start_app -u __ubsan_include -u __assert_func -u vfs_include_syscalls_impl -Wl,--undefined=uxTopUsedPriority -u app_main -u newlib_include_heap_impl -u newlib_include_syscalls_impl -u newlib_include_pthread_impl -Wl,--wrap=_Unwind_SetEnableExceptionFdeSorting -Wl,--wrap=__register_frame_info_bases -Wl,--wrap=__register_frame_info -Wl,--wrap=__register_frame -Wl,--wrap=__register_frame_info_table_bases -Wl,--wrap=__register_frame_info_table -Wl,--wrap=__register_frame_table -Wl,--wrap=__deregister_frame_info_bases -Wl,--wrap=__deregister_frame_info -Wl,--wrap=_Unwind_Find_FDE -Wl,--wrap=_Unwind_GetGR -Wl,--wrap=_Unwind_GetCFA -Wl,--wrap=_Unwind_GetIP -Wl,--wrap=_Unwind_GetIPInfo -Wl,--wrap=_Unwind_GetRegionStart -Wl,--wrap=_Unwind_GetDataRelBase -Wl,--wrap=_Unwind_GetTextRelBase -Wl,--wrap=_Unwind_SetIP -Wl,--wrap=_Unwind_SetGR -Wl,--wrap=_Unwind_GetLanguageSpecificData -Wl,--wrap=_Unwind_FindEnclosingFunction -Wl,--wrap=_Unwind_Resume -Wl,--wrap=_Unwind_RaiseException -Wl,--wrap=_Unwind_DeleteException -Wl,--wrap=_Unwind_ForcedUnwind -Wl,--wrap=_Unwind_Resume_or_Rethrow -Wl,--wrap=_Unwind_Backtrace -Wl,--wrap=__cxa_call_unexpected -Wl,--wrap=__gxx_personality_v0 -u __cxa_guard_dummy -u __cxx_fatal_exception 
 compiler.ar.flags.esp32c3=cr
-build.extra_flags.esp32c3=-DARDUINO_USB_CDC_ON_BOOT=0
+build.extra_flags.esp32c3=-DARDUINO_HW_CDC_ON_BOOT={build.cdc_on_boot}
 #
 # ESP32C3 Support End
 #