diff options
Diffstat (limited to 'Demos/Device/LowLevel/USBtoSerial/USBtoSerial.c')
| -rw-r--r-- | Demos/Device/LowLevel/USBtoSerial/USBtoSerial.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/Demos/Device/LowLevel/USBtoSerial/USBtoSerial.c b/Demos/Device/LowLevel/USBtoSerial/USBtoSerial.c new file mode 100644 index 000000000..7cef56560 --- /dev/null +++ b/Demos/Device/LowLevel/USBtoSerial/USBtoSerial.c @@ -0,0 +1,373 @@ +/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2009.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.fourwalledcubicle.com
+*/
+
+/*
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+ Permission to use, copy, modify, and distribute this software
+ and its documentation for any purpose and without fee is hereby
+ granted, provided that the above copyright notice appear in all
+ copies and that both that the copyright notice and this
+ permission notice and warranty disclaimer appear in supporting
+ documentation, and that the name of the author not be used in
+ advertising or publicity pertaining to distribution of the
+ software without specific, written prior permission.
+
+ The author disclaim all warranties with regard to this
+ software, including all implied warranties of merchantability
+ and fitness. In no event shall the author be liable for any
+ special, indirect or consequential damages or any damages
+ whatsoever resulting from loss of use, data or profits, whether
+ in an action of contract, negligence or other tortious action,
+ arising out of or in connection with the use or performance of
+ this software.
+*/
+
+#include "USBtoSerial.h"
+
+/* Scheduler Task List */
+TASK_LIST
+{
+ { .Task = USB_USBTask , .TaskStatus = TASK_STOP },
+ { .Task = CDC_Task , .TaskStatus = TASK_STOP },
+};
+
+/* Globals: */
+/** Contains the current baud rate and other settings of the virtual serial port.
+ *
+ * These values are set by the host via a class-specific request, and the physical USART should be reconfigured to match the
+ * new settings each time they are changed by the host.
+ */
+CDC_Line_Coding_t LineCoding = { .BaudRateBPS = 9600,
+ .CharFormat = OneStopBit,
+ .ParityType = Parity_None,
+ .DataBits = 8 };
+
+/** Ring (circular) buffer to hold the RX data - data from the host to the attached device on the serial port. */
+RingBuff_t Rx_Buffer;
+
+/** Ring (circular) buffer to hold the TX data - data from the attached device on the serial port to the host. */
+RingBuff_t Tx_Buffer;
+
+/** Flag to indicate if the USART is currently transmitting data from the Rx_Buffer circular buffer. */
+volatile bool Transmitting = false;
+
+/** Main program entry point. This routine configures the hardware required by the application, then
+ * starts the scheduler to run the application tasks.
+ */
+int main(void)
+{
+ /* Disable watchdog if enabled by bootloader/fuses */
+ MCUSR &= ~(1 << WDRF);
+ wdt_disable();
+
+ /* Disable clock division */
+ clock_prescale_set(clock_div_1);
+
+ /* Hardware Initialization */
+ LEDs_Init();
+ ReconfigureUSART();
+
+ /* Ring buffer Initialization */
+ Buffer_Initialize(&Rx_Buffer);
+ Buffer_Initialize(&Tx_Buffer);
+
+ /* Indicate USB not ready */
+ UpdateStatus(Status_USBNotReady);
+
+ /* Initialize Scheduler so that it can be used */
+ Scheduler_Init();
+
+ /* Initialize USB Subsystem */
+ USB_Init();
+
+ /* Scheduling - routine never returns, so put this last in the main function */
+ Scheduler_Start();
+}
+
+/** Event handler for the USB_Connect event. This indicates that the device is enumerating via the status LEDs and
+ * starts the library USB task to begin the enumeration and USB management process.
+ */
+void EVENT_USB_Connect(void)
+{
+ /* Start USB management task */
+ Scheduler_SetTaskMode(USB_USBTask, TASK_RUN);
+
+ /* Indicate USB enumerating */
+ UpdateStatus(Status_USBEnumerating);
+}
+
+/** Event handler for the USB_Disconnect event. This indicates that the device is no longer connected to a host via
+ * the status LEDs and stops the USB management and CDC management tasks.
+ */
+void EVENT_USB_Disconnect(void)
+{
+ /* Stop running CDC and USB management tasks */
+ Scheduler_SetTaskMode(CDC_Task, TASK_STOP);
+ Scheduler_SetTaskMode(USB_USBTask, TASK_STOP);
+
+ /* Reset Tx and Rx buffers, device disconnected */
+ Buffer_Initialize(&Rx_Buffer);
+ Buffer_Initialize(&Tx_Buffer);
+
+ /* Indicate USB not ready */
+ UpdateStatus(Status_USBNotReady);
+}
+
+/** Event handler for the USB_ConfigurationChanged event. This is fired when the host set the current configuration
+ * of the USB device after enumeration - the device endpoints are configured and the CDC management task started.
+ */
+void EVENT_USB_ConfigurationChanged(void)
+{
+ /* Setup CDC Notification, Rx and Tx Endpoints */
+ Endpoint_ConfigureEndpoint(CDC_NOTIFICATION_EPNUM, EP_TYPE_INTERRUPT,
+ ENDPOINT_DIR_IN, CDC_NOTIFICATION_EPSIZE,
+ ENDPOINT_BANK_SINGLE);
+
+ Endpoint_ConfigureEndpoint(CDC_TX_EPNUM, EP_TYPE_BULK,
+ ENDPOINT_DIR_IN, CDC_TXRX_EPSIZE,
+ ENDPOINT_BANK_SINGLE);
+
+ Endpoint_ConfigureEndpoint(CDC_RX_EPNUM, EP_TYPE_BULK,
+ ENDPOINT_DIR_OUT, CDC_TXRX_EPSIZE,
+ ENDPOINT_BANK_SINGLE);
+
+ /* Indicate USB connected and ready */
+ UpdateStatus(Status_USBReady);
+
+ /* Start CDC task */
+ Scheduler_SetTaskMode(CDC_Task, TASK_RUN);
+}
+
+/** Event handler for the USB_UnhandledControlPacket event. This is used to catch standard and class specific
+ * control requests that are not handled internally by the USB library (including the CDC control commands,
+ * which are all issued via the control endpoint), so that they can be handled appropriately for the application.
+ */
+void EVENT_USB_UnhandledControlPacket(void)
+{
+ uint8_t* LineCodingData = (uint8_t*)&LineCoding;
+
+ /* Process CDC specific control requests */
+ switch (USB_ControlRequest.bRequest)
+ {
+ case REQ_GetLineEncoding:
+ if (USB_ControlRequest.bmRequestType == (REQDIR_DEVICETOHOST | REQTYPE_CLASS | REQREC_INTERFACE))
+ {
+ /* Acknowledge the SETUP packet, ready for data transfer */
+ Endpoint_ClearSETUP();
+
+ /* Write the line coding data to the control endpoint */
+ Endpoint_Write_Control_Stream_LE(LineCodingData, sizeof(LineCoding));
+
+ /* Finalize the stream transfer to send the last packet or clear the host abort */
+ Endpoint_ClearOUT();
+ }
+
+ break;
+ case REQ_SetLineEncoding:
+ if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_INTERFACE))
+ {
+ /* Acknowledge the SETUP packet, ready for data transfer */
+ Endpoint_ClearSETUP();
+
+ /* Read the line coding data in from the host into the global struct */
+ Endpoint_Read_Control_Stream_LE(LineCodingData, sizeof(LineCoding));
+
+ /* Finalize the stream transfer to clear the last packet from the host */
+ Endpoint_ClearIN();
+
+ /* Reconfigure the USART with the new settings */
+ ReconfigureUSART();
+ }
+
+ break;
+ case REQ_SetControlLineState:
+ if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_INTERFACE))
+ {
+ /* Acknowledge the SETUP packet, ready for data transfer */
+ Endpoint_ClearSETUP();
+
+ /* NOTE: Here you can read in the line state mask from the host, to get the current state of the output handshake
+ lines. The mask is read in from the wValue parameter in USB_ControlRequest, and can be masked against the
+ CONTROL_LINE_OUT_* masks to determine the RTS and DTR line states using the following code:
+ */
+
+ /* Acknowledge status stage */
+ while (!(Endpoint_IsINReady()));
+ Endpoint_ClearIN();
+ }
+
+ break;
+ }
+}
+
+/** Task to manage CDC data transmission and reception to and from the host, from and to the physical USART. */
+TASK(CDC_Task)
+{
+ if (USB_IsConnected)
+ {
+#if 0
+ /* NOTE: Here you can use the notification endpoint to send back line state changes to the host, for the special RS-232
+ handshake signal lines (and some error states), via the CONTROL_LINE_IN_* masks and the following code:
+ */
+
+ USB_Notification_Header_t Notification = (USB_Notification_Header_t)
+ {
+ .NotificationType = (REQDIR_DEVICETOHOST | REQTYPE_CLASS | REQREC_INTERFACE),
+ .Notification = NOTIF_SerialState,
+ .wValue = 0,
+ .wIndex = 0,
+ .wLength = sizeof(uint16_t),
+ };
+
+ uint16_t LineStateMask;
+
+ // Set LineStateMask here to a mask of CONTROL_LINE_IN_* masks to set the input handshake line states to send to the host
+
+ Endpoint_SelectEndpoint(CDC_NOTIFICATION_EPNUM);
+ Endpoint_Write_Stream_LE(&Notification, sizeof(Notification));
+ Endpoint_Write_Stream_LE(&LineStateMask, sizeof(LineStateMask));
+ Endpoint_ClearIN();
+#endif
+
+ /* Select the Serial Rx Endpoint */
+ Endpoint_SelectEndpoint(CDC_RX_EPNUM);
+
+ /* Check to see if a packet has been received from the host */
+ if (Endpoint_IsOUTReceived())
+ {
+ /* Read the bytes in from the endpoint into the buffer while space is available */
+ while (Endpoint_BytesInEndpoint() && (BUFF_STATICSIZE - Rx_Buffer.Elements))
+ {
+ /* Store each character from the endpoint */
+ Buffer_StoreElement(&Rx_Buffer, Endpoint_Read_Byte());
+ }
+
+ /* Check to see if all bytes in the current packet have been read */
+ if (!(Endpoint_BytesInEndpoint()))
+ {
+ /* Clear the endpoint buffer */
+ Endpoint_ClearOUT();
+ }
+ }
+
+ /* Check if Rx buffer contains data - if so, send it */
+ if (Rx_Buffer.Elements)
+ Serial_TxByte(Buffer_GetElement(&Rx_Buffer));
+
+ /* Select the Serial Tx Endpoint */
+ Endpoint_SelectEndpoint(CDC_TX_EPNUM);
+
+ /* Check if the Tx buffer contains anything to be sent to the host */
+ if (Tx_Buffer.Elements)
+ {
+ /* Wait until Serial Tx Endpoint Ready for Read/Write */
+ while (!(Endpoint_IsReadWriteAllowed()));
+
+ /* Write the bytes from the buffer to the endpoint while space is available */
+ while (Tx_Buffer.Elements && (Endpoint_BytesInEndpoint() < CDC_TXRX_EPSIZE))
+ {
+ /* Write each byte retreived from the buffer to the endpoint */
+ Endpoint_Write_Byte(Buffer_GetElement(&Tx_Buffer));
+ }
+
+ /* Remember if the packet to send completely fills the endpoint */
+ bool IsFull = (Endpoint_BytesInEndpoint() == CDC_TXRX_EPSIZE);
+
+ /* Send the data */
+ Endpoint_ClearIN();
+
+ /* If no more data to send and the last packet filled the endpoint, send an empty packet to release
+ * the buffer on the receiver (otherwise all data will be cached until a non-full packet is received) */
+ if (IsFull && !(Tx_Buffer.Elements))
+ {
+ /* Wait until Serial Tx Endpoint Ready for Read/Write */
+ while (!(Endpoint_IsReadWriteAllowed()));
+
+ /* Send an empty packet to terminate the transfer */
+ Endpoint_ClearIN();
+ }
+ }
+ }
+}
+
+/** ISR to handle the USART receive complete interrupt, fired each time the USART has received a character. This stores the received
+ * character into the Tx_Buffer circular buffer for later transmission to the host.
+ */
+ISR(USART1_RX_vect, ISR_BLOCK)
+{
+ /* Only store received characters if the USB interface is connected */
+ if (USB_IsConnected)
+ {
+ /* Character received, store it into the buffer */
+ Buffer_StoreElement(&Tx_Buffer, UDR1);
+ }
+}
+
+/** Function to manage status updates to the user. This is done via LEDs on the given board, if available, but may be changed to
+ * log to a serial port, or anything else that is suitable for status updates.
+ *
+ * \param CurrentStatus Current status of the system, from the USBtoSerial_StatusCodes_t enum
+ */
+void UpdateStatus(uint8_t CurrentStatus)
+{
+ uint8_t LEDMask = LEDS_NO_LEDS;
+
+ /* Set the LED mask to the appropriate LED mask based on the given status code */
+ switch (CurrentStatus)
+ {
+ case Status_USBNotReady:
+ LEDMask = (LEDS_LED1);
+ break;
+ case Status_USBEnumerating:
+ LEDMask = (LEDS_LED1 | LEDS_LED2);
+ break;
+ case Status_USBReady:
+ LEDMask = (LEDS_LED2 | LEDS_LED4);
+ break;
+ }
+
+ /* Set the board LEDs to the new LED mask */
+ LEDs_SetAllLEDs(LEDMask);
+}
+
+/** Reconfigures the USART to match the current serial port settings issued by the host as closely as possible. */
+void ReconfigureUSART(void)
+{
+ uint8_t ConfigMask = 0;
+
+ /* Determine parity - non odd/even parity mode defaults to no parity */
+ if (LineCoding.ParityType == Parity_Odd)
+ ConfigMask = ((1 << UPM11) | (1 << UPM10));
+ else if (LineCoding.ParityType == Parity_Even)
+ ConfigMask = (1 << UPM11);
+
+ /* Determine stop bits - 1.5 stop bits is set as 1 stop bit due to hardware limitations */
+ if (LineCoding.CharFormat == TwoStopBits)
+ ConfigMask |= (1 << USBS1);
+
+ /* Determine data size - 5, 6, 7, or 8 bits are supported */
+ if (LineCoding.DataBits == 6)
+ ConfigMask |= (1 << UCSZ10);
+ else if (LineCoding.DataBits == 7)
+ ConfigMask |= (1 << UCSZ11);
+ else if (LineCoding.DataBits == 8)
+ ConfigMask |= ((1 << UCSZ11) | (1 << UCSZ10));
+
+ /* Enable double speed, gives better error percentages at 8MHz */
+ UCSR1A = (1 << U2X1);
+
+ /* Enable transmit and receive modules and interrupts */
+ UCSR1B = ((1 << RXCIE1) | (1 << TXEN1) | (1 << RXEN1));
+
+ /* Set the USART mode to the mask generated by the Line Coding options */
+ UCSR1C = ConfigMask;
+
+ /* Set the USART baud rate register to the desired baud rate value */
+ UBRR1 = SERIAL_2X_UBBRVAL((uint16_t)LineCoding.BaudRateBPS);
+}
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