diff --git a/cores/arduino/CDC.cpp b/cores/arduino/CDC.cpp index fb0c0e0..3dbf15d 100644 --- a/cores/arduino/CDC.cpp +++ b/cores/arduino/CDC.cpp @@ -23,21 +23,6 @@ #if defined(USBCON) #ifdef CDC_ENABLED -#if (RAMEND < 1000) -#define SERIAL_BUFFER_SIZE 16 -#else -#define SERIAL_BUFFER_SIZE 64 -#endif - -struct ring_buffer -{ - unsigned char buffer[SERIAL_BUFFER_SIZE]; - volatile int head; - volatile int tail; -}; - -ring_buffer cdc_rx_buffer = { { 0 }, 0, 0}; - typedef struct { u32 dwDTERate; @@ -129,7 +114,6 @@ bool WEAK CDC_Setup(Setup& setup) } -int _serialPeek = -1; void Serial_::begin(unsigned long baud_count) { } @@ -142,55 +126,29 @@ void Serial_::end(void) { } -void Serial_::accept(void) -{ - ring_buffer *buffer = &cdc_rx_buffer; - int i = (unsigned int)(buffer->head+1) % SERIAL_BUFFER_SIZE; - - // if we should be storing the received character into the location - // just before the tail (meaning that the head would advance to the - // current location of the tail), we're about to overflow the buffer - // and so we don't write the character or advance the head. - - // while we have room to store a byte - while (i != buffer->tail) { - int c = USB_Recv(CDC_RX); - if (c == -1) - break; // no more data - buffer->buffer[buffer->head] = c; - buffer->head = i; - - i = (unsigned int)(buffer->head+1) % SERIAL_BUFFER_SIZE; - } -} - int Serial_::available(void) { - ring_buffer *buffer = &cdc_rx_buffer; - return (unsigned int)(SERIAL_BUFFER_SIZE + buffer->head - buffer->tail) % SERIAL_BUFFER_SIZE; + if (peek_buffer >= 0) { + return 1; + } + return USB_Available(CDC_RX); } int Serial_::peek(void) { - ring_buffer *buffer = &cdc_rx_buffer; - if (buffer->head == buffer->tail) { - return -1; - } else { - return buffer->buffer[buffer->tail]; - } + if (peek_buffer < 0) + peek_buffer = USB_Recv(CDC_RX); + return peek_buffer; } int Serial_::read(void) { - ring_buffer *buffer = &cdc_rx_buffer; - // if the head isn't ahead of the tail, we don't have any characters - if (buffer->head == buffer->tail) { - return -1; - } else { - unsigned char c = buffer->buffer[buffer->tail]; - buffer->tail = (unsigned int)(buffer->tail + 1) % SERIAL_BUFFER_SIZE; + if (peek_buffer >= 0) { + int c = peek_buffer; + peek_buffer = -1; return c; - } + } + return USB_Recv(CDC_RX); } void Serial_::flush(void) diff --git a/cores/arduino/USBAPI.h b/cores/arduino/USBAPI.h index 1c5ecf0..d506b58 100644 --- a/cores/arduino/USBAPI.h +++ b/cores/arduino/USBAPI.h @@ -28,14 +28,13 @@ extern USBDevice_ USBDevice; class Serial_ : public Stream { private: - ring_buffer *_cdc_rx_buffer; + int peek_buffer; public: void begin(unsigned long); void begin(unsigned long, uint8_t); void end(void); virtual int available(void); - virtual void accept(void); virtual int peek(void); virtual int read(void); virtual void flush(void); diff --git a/cores/arduino/USBCore.cpp b/cores/arduino/USBCore.cpp index 76ceb01..f8123e5 100644 --- a/cores/arduino/USBCore.cpp +++ b/cores/arduino/USBCore.cpp @@ -614,8 +614,6 @@ ISR(USB_GEN_vect) { #ifdef CDC_ENABLED USB_Flush(CDC_TX); // Send a tx frame if found - if (USB_Available(CDC_RX)) // Handle received bytes (if any) - Serial.accept(); #endif // check whether the one-shot period has elapsed. if so, turn off the LED