I am attempting to use the LUFA library (https://www.fourwalledcubicle.com/files/LUFA/Doc/210130/html/index.html) to configure a program for the ATMEGA16U2. I want it to show up on windows as a COM port to allow for messages to be sent over serial. If the ATMEGA16U2 receives a byte 'F', it should drive pin PB7 (pin 20) high, and if it receives a '0', it should drive the same pin low. I also want it to echo back what was sent over serial. I was able to get this code to compile and build, but no response from the microcontroller and no change in pin voltage was seen. I am not sure if it is not configured properly, or if I have an entirely different issue occurring.
The code is seen below:
/*
LUFA Library
Copyright (C) Dean Camera, 2015.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
Copyright 2015 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
without fee, 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 disclaims 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.
*/
/** \file
*
* Main source file for the VirtualSerial demo. This file contains the main tasks of
* the demo and is responsible for the initial application hardware configuration.
*/
#include "VirtualSerial.h"
#include <avr/io.h>
#include <util/delay.h>
#define USB_OPT_AUTO_PLL (0 << 2)
#define USB_OPT_REG_ENABLED (0 << 1)
#define USB_DEVICE_OPT_FULLSPEED (0 << 0)
/** LUFA CDC Class driver interface configuration and state information. This structure is
* passed to all CDC Class driver functions, so that multiple instances of the same class
* within a device can be differentiated from one another.
*/
USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
{
.Config =
{
.ControlInterfaceNumber = INTERFACE_ID_CDC_CCI,
.DataINEndpoint =
{
.Address = CDC_TX_EPADDR,
.Size = CDC_TXRX_EPSIZE,
.Banks = 1,
},
.DataOUTEndpoint =
{
.Address = CDC_RX_EPADDR,
.Size = CDC_TXRX_EPSIZE,
.Banks = 1,
},
.NotificationEndpoint =
{
.Address = CDC_NOTIFICATION_EPADDR,
.Size = CDC_NOTIFICATION_EPSIZE,
.Banks = 1,
},
},
};
/** Standard file stream for the CDC interface when set up, so that the virtual CDC COM port can be
* used like any regular character stream in the C APIs.
*/
static FILE USBSerialStream;
/** Main program entry point. This routine contains the overall program flow, including initial
* setup of all components and the main program loop.
*/
int main(void)
{
// Setup pin 20 (PB0) as output
DDRB |= (1 << PB6); // Data Direction Register for Port B
PORTB &= ~(1 << PB6); // Start with pin 20 low
DDRC |= _BV(DDC5);
SetupHardware();
PORTC |= _BV(PC5);
/* Create a regular character stream for the interface so that it can be used with the stdio.h functions */
CDC_Device_CreateStream(&VirtualSerial_CDC_Interface, &USBSerialStream);
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
GlobalInterruptEnable();
for (;;)
{
int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface); // This returns -1 if no data received, otherwise returns the byte
if (ReceivedByte >= 0) // Ensure a byte was actually received
{
if (ReceivedByte == 'F') // Check if received byte is 'F'
{
PORTB |= (1 << PB6); // Set pin 20 high
}
else if (ReceivedByte == '0') // Check if received byte is '0'
{
PORTB &= ~(1 << PB6); // Set pin 20 low
}
// Respond to the PC with "Message received" after any byte is received
CDC_Device_SendString(&VirtualSerial_CDC_Interface, "Message received");
}
CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
USB_USBTask();
}
}
/** Configures the board hardware and chip peripherals for the demo's functionality. */
void SetupHardware(void)
{
#if (ARCH == ARCH_AVR8)
/* Disable watchdog if enabled by bootloader/fuses */
MCUSR &= ~(1 << WDRF);
wdt_disable();
/* Disable clock division */
clock_prescale_set(clock_div_1);
#elif (ARCH == ARCH_XMEGA)
/* Start the PLL to multiply the 2MHz RC oscillator to 32MHz and switch the CPU core to run from it */
XMEGACLK_StartPLL(CLOCK_SRC_INT_RC2MHZ, 2000000, F_CPU);
XMEGACLK_SetCPUClockSource(CLOCK_SRC_PLL);
/* Start the 32MHz internal RC oscillator and start the DFLL to increase it to 48MHz using the USB SOF as a reference */
XMEGACLK_StartInternalOscillator(CLOCK_SRC_INT_RC32MHZ);
XMEGACLK_StartDFLL(CLOCK_SRC_INT_RC32MHZ, DFLL_REF_INT_USBSOF, F_USB);
PMIC.CTRL = PMIC_LOLVLEN_bm | PMIC_MEDLVLEN_bm | PMIC_HILVLEN_bm;
#endif
/* Hardware Initialization */
LEDs_Init();
USB_Init(1);
}
/** Event handler for the library USB Connection event. */
void EVENT_USB_Device_Connect(void)
{
LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
}
/** Event handler for the library USB Disconnection event. */
void EVENT_USB_Device_Disconnect(void)
{
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
}
/** Event handler for the library USB Configuration Changed event. */
void EVENT_USB_Device_ConfigurationChanged(void)
{
bool ConfigSuccess = true;
ConfigSuccess &= CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);
LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
}
/** Event handler for the library USB Control Request reception event. */
void EVENT_USB_Device_ControlRequest(void)
{
CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
}
/** CDC class driver callback function the processing of changes to the virtual
* control lines sent from the host..
*
* \param[in] CDCInterfaceInfo Pointer to the CDC class interface configuration structure being referenced
*/
void EVENT_CDC_Device_ControLineStateChanged(USB_ClassInfo_CDC_Device_t *const CDCInterfaceInfo)
{
/* You can get changes to the virtual CDC lines in this callback; a common
use-case is to use the Data Terminal Ready (DTR) flag to enable and
disable CDC communications in your application when set to avoid the
application blocking while waiting for a host to become ready and read
in the pending data from the USB endpoints.
*/
/*bool HostReady = (CDCInterfaceInfo->State.ControlLineStates.HostToDevice & CDC_CONTROL_LINE_OUT_DTR) != 0;*/
}
void HandleError(void)
{
;
// For example, blink an LED to signal an error
// for (int i = 0; i < 5; i++) { // Blink 5 times
// LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
// _delay_ms(200);
// LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
// _delay_ms(200);
// }
// You can also add other hardware-specific error handling code here, if needed
}
void SendSpecificString(void)
{
char* ReportString = NULL;
static bool ActionSent = false;
ReportString = "data packet\r\n";
if ((ReportString != NULL) && (ActionSent == false))
{
ActionSent = true;
/* Write the string to the virtual COM port via the created character stream */
if (fputs(ReportString, &USBSerialStream) == EOF) {
// Log error to the serial stream (if another debug stream is available)
// fputs("Error: Failed to write to USBSerialStream\n", &DebugStream);
// Call the error handler
HandleError();
}
}
}